Shareholder Report |
6 Months Ended | |||||||||||||||||||||||||
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Jun. 30, 2026
USD ($)
Holding
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| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Document Type | N-CSRS | |||||||||||||||||||||||||
| Amendment Flag | false | |||||||||||||||||||||||||
| Registrant Name | American Funds Insurance Series | |||||||||||||||||||||||||
| Entity Central Index Key | 0000729528 | |||||||||||||||||||||||||
| Entity Investment Company Type | N-1A | |||||||||||||||||||||||||
| Document Period End Date | Jun. 30, 2026 | |||||||||||||||||||||||||
| American Funds Global Growth Portfolio - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® Global Growth Portfolio | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds Global Growth Portfolio (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment )
*Annualized.
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| Expenses Paid, Amount | $ 27 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.51% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 89,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 6 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 7.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
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| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
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| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was
appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure. |
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| American Funds Growth and Income Portfolio - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® Growth and Income Portfolio | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds Growth and Income Portfolio (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment )
*Annualized.
|
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| Expenses Paid, Amount | $ 26 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.51% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 450,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 8 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 7.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
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| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
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| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was
appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure. |
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| American Funds Managed Risk Growth Portfolio - Class P2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® Managed Risk Growth Portfolio | |||||||||||||||||||||||||
| Class Name | Class P2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds Managed Risk Growth Portfolio (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-P2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-P2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
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| Expenses Paid, Amount | $ 31 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.61% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 1,791,623,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 25 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 18.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
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| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)![]() *Includes derivatives.
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| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
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| American Funds Managed Risk Growth and Income Portfolio - Class P2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® Managed Risk Growth and Income Portfolio | |||||||||||||||||||||||||
| Class Name | Class P2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds Managed Risk Growth and Income Portfolio (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-P2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-P2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment )
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 31 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.61% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 1,310,595,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 24 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 16.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
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| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets) *Includes derivatives. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the
independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure. |
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| American Funds Managed Risk Global Allocation Portfolio - Class P2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® Managed Risk Global Allocation Portfolio | |||||||||||||||||||||||||
| Class Name | Class P2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds Managed Risk Global Allocation Portfolio (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-P2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-P2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
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| Expenses Paid, Amount | $ 33 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.63% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 357,545,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 18 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 17.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
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| Holdings [Text Block] | Portfolio holdings by fund type *Includes derivatives. |
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| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
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| American Funds IS 2070 Target Date Retirement Fund - Class 1 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2070 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2070 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment )
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.06% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 2,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 17 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 5.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
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| Holdings [Text Block] | Portfolio holdings by fund type
|
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| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025,
PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the period May 1, 2024 (commencement of operations) through December 31, 2024, fiscal year ended December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure. |
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| American Funds IS 2070 Target Date Retirement Fund - Class 1A | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2070 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1A | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2070 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1A. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1A | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.05% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 2,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 17 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 5.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
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| Holdings [Text Block] | Portfolio holdings by fund type
|
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| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee,
as part of a broader effort to update board oversight and fund operations. At no point during the period May 1, 2024 (commencement of operations) through December 31, 2024, fiscal year ended December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure. |
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| American Funds IS 2070 Target Date Retirement Fund - Class 2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2070 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2070 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.06% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 2,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 17 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 5.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
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| Holdings [Text Block] | Portfolio holdings by fund type
|
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| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The
change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the period May 1, 2024 (commencement of operations) through December 31, 2024, fiscal year ended December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure. |
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| American Funds IS 2070 Target Date Retirement Fund - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2070 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2070 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.05% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 2,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 17 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 5.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
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| Holdings [Text Block] | Portfolio holdings by fund type
|
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| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as
the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the period May 1, 2024 (commencement of operations) through December 31, 2024, fiscal year ended December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure. |
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| American Funds IS 2065 Target Date Retirement Fund - Class 1 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2065 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2065 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.06% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 698,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 17 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 12.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2065 Target Date Retirement Fund - Class 1A | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2065 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1A | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2065 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1A. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1A | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.05% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 698,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 17 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 12.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2065 Target Date Retirement Fund - Class 2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2065 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2065 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment )
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.05% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 698,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 17 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 12.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2065 Target Date Retirement Fund - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2065 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2065 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 8 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.16% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 698,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 17 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 12.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2060 Target Date Retirement Fund - Class 1 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2060 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2060 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.06% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 1,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 18 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 6.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2060 Target Date Retirement Fund - Class 1A | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2060 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1A | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2060 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1A. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1A | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.05% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 1,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 18 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 6.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets) *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2060 Target Date Retirement Fund - Class 2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2060 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2060 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.05% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 1,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 18 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 6.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets) *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2060 Target Date Retirement Fund - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2060 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2060 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 15 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.28% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 1,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 18 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 6.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)![]() *Less than 0.01%.
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2055 Target Date Retirement Fund - Class 1 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2055 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2055 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 10,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 20 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 16.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2055 Target Date Retirement Fund - Class 1A | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2055 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1A | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2055 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1A. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1A | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 10,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 20 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 16.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2055 Target Date Retirement Fund - Class 2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2055 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2055 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 10,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 20 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 16.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2055 Target Date Retirement Fund - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2055 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2055 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 10,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 20 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 16.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2050 Target Date Retirement Fund - Class 1 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2050 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2050 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 15,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 20 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 10.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2050 Target Date Retirement Fund - Class 1A | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2050 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1A | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2050 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1A. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1A | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.03% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 15,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 20 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 10.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2050 Target Date Retirement Fund - Class 2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2050 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2050 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.03% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 15,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 20 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 10.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (perc ent of net assets) |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2050 Target Date Retirement Fund - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2050 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2050 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 8 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.15% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 15,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 20 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 10.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2045 Target Date Retirement Fund - Class 1 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2045 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2045 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.05% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 21,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 25 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 23.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdin (percent of net assets)gs by fund type |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2045 Target Date Retirement Fund - Class 1A | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2045 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1A | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2045 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1A. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1A | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 21,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 25 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 23.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio hold (percent of net assets)ings by fund type |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2045 Target Date Retirement Fund - Class 2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2045 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2045 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 21,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 25 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 23.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of ne t assets) |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2045 Target Date Retirement Fund - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2045 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2045 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
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| Expenses Paid, Amount | $ 7 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.13% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 21,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 25 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 23.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
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| Holdings [Text Block] | Portfolio holdings by (percent of net assets) fund t ype |
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| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
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| American Funds IS 2040 Target Date Retirement Fund - Class 1 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2040 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2040 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
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| Expenses Paid, Amount | $ 4 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.07% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 23,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 26 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 16.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statist ic s
|
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| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets) *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
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| American Funds IS 2040 Target Date Retirement Fund - Class 1A | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2040 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1A | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2040 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1A. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1A | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 23,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 26 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 16.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets) *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagre emen ts with accountantsOn December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
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| American Funds IS 2040 Target Date Retirement Fund - Class 2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2040 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2040 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investme nt)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 23,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 26 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 16.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets) *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2040 Target Date Retirement Fund - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2040 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2040 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 28 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.54% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 23,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 26 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 16.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets) *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements w ith a ccountantsOn December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2035 Target Date Retirement Fund - Class 1 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2035 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2035 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,00 0 investm ent)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.05% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 40,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 24 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 12.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets) *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2035 Target Date Retirement Fund - Class 1A | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2035 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1A | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2035 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1A. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1A | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 in vestmen t)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 1 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.02% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 40,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 24 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 12.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets) *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2035 Target Date Retirement Fund - Class 2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2035 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2035 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 1 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.02% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 40,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 24 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 12.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets) *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountantsOn December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2035 Target Date Retirement Fund - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2035 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2035 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetica l $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 26 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.51% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 40,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 24 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 12.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets) *Less than 0.01%. |
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
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| American Funds® IS 2030 Target Date Retirement Fund - Class 1 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2030 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2030 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.06% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 47,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 25 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 12.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds® IS 2030 Target Date Retirement Fund - Class 1A | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2030 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 1A | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2030 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1A. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1A | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 47,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 25 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 12.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds® IS 2030 Target Date Retirement Fund - Class 2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2030 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2030 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 47,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 25 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 12.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds® IS 2030 Target Date Retirement Fund - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2030 Target Date Retirement Fund | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2030 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 27 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.53% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 47,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 25 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 12.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds® IS 2025 Target Date Retirement Income Fund - Class 1 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2025 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 1 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2025 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.06% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 26,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 21 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 15.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type ![]() *Less than 0.01%.
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds® IS 2025 Target Date Retirement Income Fund - Class 1A | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2025 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 1A | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2025 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1A. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1A | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 26,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 21 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 15.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type ![]() *Less than 0.01%.
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds® IS 2025 Target Date Retirement Income Fund - Class 2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2025 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2025 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 26,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 21 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 15.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type ![]() *Less than 0.01%.
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds® IS 2025 Target Date Retirement Income Fund - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2025 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2025 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund atcapitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 27 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.54% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 26,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 21 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 15.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type
*Less than 0.01%.
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants
On December 10, 2025 , PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure. |
|||||||||||||||||||||||||
| American Funds® IS 2020 Target Date Retirement Income Fund - Class 1 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2020 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 1 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2020 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.06% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 41,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 21 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 8.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund sta ti stics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds® IS 2020 Target Date Retirement Income Fund - Class 1A | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2020 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 1A | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2020 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1A. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1A | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (bas ed on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 41,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 21 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 8.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds® IS 2020 Target Date Retirement Income Fund - Class 2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2020 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2020 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 41,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 21 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 8.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund (percent of net assets) ty pe
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds® IS 2020 Target Date Retirement Income Fund - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2020 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2020 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 28 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.55% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 41,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 21 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 8.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements wit h acco untantsOn December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds® IS 2015 Target Date Retirement Income Fund - Class 1 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2015 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 1 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2015 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund atcapitalgroup.com/AFIS-literature-1. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 3 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.05% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 144,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 18 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 7.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, P
ricewaterhou seCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure. |
|||||||||||||||||||||||||
| American Funds® IS 2015 Target Date Retirement Income Fund - Class 1A | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2015 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 1A | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2015 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund atcapitalgroup.com/AFIS-literature-1A. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1A | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 144,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 18 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 7.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with ac cou ntantsOn December 10, 2025, P
ricewaterhouseCoope rs LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal yea r ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure. |
|||||||||||||||||||||||||
| American Funds® IS 2015 Target Date Retirement Income Fund - Class 2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2015 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2015 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 144,000,000 | |||||||||||||||||||||||||
| Holdings Count | 18 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 7.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2015 Target Date Fund - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2015 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2015 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 28 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.55% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 144,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 18 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 7.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2010 Target Date Fund - Class 1 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2010 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 1 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2010 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-1. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 538,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 16 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 4.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2010 Target Date Retirement Income Fund - Class 1A | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2010 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 1A | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2010 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional informationabout the fund at capitalgroup.com/AFIS-literature-1A. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-1A | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 538,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 16 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 4.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
|
|||||||||||||||||||||||||
| American Funds IS 2010 Target Date Retirement Income Fund - Class 2 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2010 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 2 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2010 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-2. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-2 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
|
|||||||||||||||||||||||||
| Expenses Paid, Amount | $ 2 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.04% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 538,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 16 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 4.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
|
|||||||||||||||||||||||||
| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
|
|||||||||||||||||||||||||
| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during
the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure. |
|||||||||||||||||||||||||
| American Funds IS 2010 Target Date Retirement Income Fund - Class 4 | ||||||||||||||||||||||||||
| Shareholder Report [Line Items] | ||||||||||||||||||||||||||
| Fund Name | American Funds® IS 2010 Target Date Retirement Income Fund | |||||||||||||||||||||||||
| Class Name | Class 4 | |||||||||||||||||||||||||
| No Trading Symbol Flag | true | |||||||||||||||||||||||||
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about American Funds IS 2010 Target Date Fund (the "fund") for the period from January 1, 2026 to June 30, 2026. | |||||||||||||||||||||||||
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |||||||||||||||||||||||||
| Additional Information [Text Block] | You can find additional information about the fund at capitalgroup.com/AFIS-literature-4. You can also request this information by contacting us at (800) 421-4225. | |||||||||||||||||||||||||
| Additional Information Phone Number | (800) 421-4225 | |||||||||||||||||||||||||
| Additional Information Website | capitalgroup.com/AFIS-literature-4 | |||||||||||||||||||||||||
| Expenses [Text Block] | What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)
*Annualized.
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| Expenses Paid, Amount | $ 27 | |||||||||||||||||||||||||
| Expense Ratio, Percent | 0.53% | [1] | ||||||||||||||||||||||||
| Net Assets | $ 538,000,000 | |||||||||||||||||||||||||
| Holdings Count | Holding | 16 | |||||||||||||||||||||||||
| Investment Company, Portfolio Turnover | 4.00% | |||||||||||||||||||||||||
| Additional Fund Statistics [Text Block] | Key fund statistics
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| Holdings [Text Block] | Portfolio holdings by fund type (percent of net assets)
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| Accountant Change Date | Dec. 10, 2025 | |||||||||||||||||||||||||
| Accountant Change Disagreements [Text Block] | Changes in and disagreements with accountants On December 10, 2025, PricewaterhouseCoopers LLP (“PwC”) was dismissed and Deloitte & Touche LLP was appointed as the fund’s independent registered public accounting firm for the fiscal year ending December 31, 2026 audit. The change in the fund’s independent registered public accounting firm was approved by the fund’s board of trustees, including a majority of the independent trustees, upon recommendation of the audit committee, as part of a broader effort to update board oversight and fund operations. At no point during the fund’s fiscal years ended December 31, 2024 and December 31, 2025 and the subsequent interim period through February 13, 2026, were there any disagreements between management and PwC on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.
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