v3.26.1
Shareholder Report
 6 Months Ended
Jun. 30, 2026
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name JOHN HANCOCK VARIABLE INSURANCE TRUST
Entity Central Index Key 0000756913
Entity Investment Company Type N-1A
Document Period End Date Jun. 30, 2026
C000022588 [Member]  
Shareholder Report [Line Items]  
Fund Name Managed Volatility Growth Portfolio
Class Name Series NAV
Trading Symbol JAIZX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about the Managed Volatility Growth Portfolio (the fund) for the period of 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 dfinview.com/johnhancock?site=funds. You can also request this information by contacting us at 800-344-1029 for John Hancock Variable Annuities and 800-732-5543 for John Hancock Variable Life Insurance.
Additional Information Phone Number 800-344-1029800-732-5543
Additional Information Website dfinview.com/johnhancock?site=funds
Expenses [Text Block]
What were the fund costs during the last six months ?
(Based on a hypothetical $10,000 investment)
Fund (Class) Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
Managed Volatility Growth Portfolio
(Series NAV/JAIZX)		 $8 0.16%
Expenses Paid, Amount $ 8
Expense Ratio, Percent 0.16%
Net Assets $ 5,240,449,924
Holdings Count | Holding 42
Investment Company Portfolio Turnover 51.00%
Additional Fund Statistics [Text Block]
Fund Statistics
Fund net assets $5,240,449,924
Total number of portfolio holdings 42
Portfolio turnover rate 51%
Holdings [Text Block]
Graphical Representation of Holdings
The table below shows the investment makeup of the fund, representing a percentage of the total net assets of the fund.
Asset Allocation
Affiliated investment companies 94.8%
Equity 68.2%
Large blend 21.2%
U.S. large cap 20.7%
International equity 11.0%
Emerging-market equity 6.9%
U.S. mid cap 6.4%
U.S. small cap 2.0%
Fixed income 22.9%
Intermediate bond 12.6%
Emerging-market debt 2.5%
Short-term bond 2.3%
Bank loan 2.0%
High yield bond 2.0%
Multi-sector bond 1.5%
Alternative and specialty 3.7%
Sector equity 2.2%
Multi-asset income 1.5%
U.S. Government 3.6%
Short-term investments and other 1.6%
Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time.
C000022590 [Member]  
Shareholder Report [Line Items]  
Fund Name Managed Volatility Growth Portfolio
Class Name Series II
Trading Symbol JAJAX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about the Managed Volatility Growth Portfolio (the fund) for the period of 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 dfinview.com/johnhancock?site=funds. You can also request this information by contacting us at 800-344-1029 for John Hancock Variable Annuities and 800-732-5543 for John Hancock Variable Life Insurance.
Additional Information Phone Number 800-344-1029800-732-5543
Additional Information Website dfinview.com/johnhancock?site=funds
Expenses [Text Block]
What were the fund costs during the last six months ?
(Based on a hypothetical $10,000 investment)
Fund (Class) Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
Managed Volatility Growth Portfolio
(Series II/JAJAX)		 $21 0.41%
Expenses Paid, Amount $ 21
Expense Ratio, Percent 0.41%
Net Assets $ 5,240,449,924
Holdings Count | Holding 42
Investment Company Portfolio Turnover 51.00%
Additional Fund Statistics [Text Block]
Fund Statistics
Fund net assets $5,240,449,924
Total number of portfolio holdings 42
Portfolio turnover rate 51%
Holdings [Text Block]
Graphical Representation of Holdings
The table below shows the investment makeup of the fund, representing a percentage of the total net assets of the fund.
Asset Allocation
Affiliated investment companies 94.8%
Equity 68.2%
Large blend 21.2%
U.S. large cap 20.7%
International equity 11.0%
Emerging-market equity 6.9%
U.S. mid cap 6.4%
U.S. small cap 2.0%
Fixed income 22.9%
Intermediate bond 12.6%
Emerging-market debt 2.5%
Short-term bond 2.3%
Bank loan 2.0%
High yield bond 2.0%
Multi-sector bond 1.5%
Alternative and specialty 3.7%
Sector equity 2.2%
Multi-asset income 1.5%
U.S. Government 3.6%
Short-term investments and other 1.6%
Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time.
C000022589 [Member]  
Shareholder Report [Line Items]  
Fund Name Managed Volatility Growth Portfolio
Class Name Series I
Trading Symbol JELGX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about the Managed Volatility Growth Portfolio (the fund) for the period of 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 dfinview.com/johnhancock?site=funds. You can also request this information by contacting us at 800-344-1029 for John Hancock Variable Annuities and 800-732-5543 for John Hancock Variable Life Insurance.
Additional Information Phone Number 800-344-1029800-732-5543
Additional Information Website dfinview.com/johnhancock?site=funds
Expenses [Text Block]
What were the fund costs during the last six months ?
(Based on a hypothetical $10,000 investment)
Fund (Class) Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
Managed Volatility Growth Portfolio
(Series I/JELGX)		 $11 0.21%
Expenses Paid, Amount $ 11
Expense Ratio, Percent 0.21%
Net Assets $ 5,240,449,924
Holdings Count | Holding 42
Investment Company Portfolio Turnover 51.00%
Additional Fund Statistics [Text Block]
Fund Statistics
Fund net assets $5,240,449,924
Total number of portfolio holdings 42
Portfolio turnover rate 51%
Holdings [Text Block]
Graphical Representation of Holdings
The table below shows the investment makeup of the fund, representing a percentage of the total net assets of the fund.
Asset Allocation
Affiliated investment companies 94.8%
Equity 68.2%
Large blend 21.2%
U.S. large cap 20.7%
International equity 11.0%
Emerging-market equity 6.9%
U.S. mid cap 6.4%
U.S. small cap 2.0%
Fixed income 22.9%
Intermediate bond 12.6%
Emerging-market debt 2.5%
Short-term bond 2.3%
Bank loan 2.0%
High yield bond 2.0%
Multi-sector bond 1.5%
Alternative and specialty 3.7%
Sector equity 2.2%
Multi-asset income 1.5%
U.S. Government 3.6%
Short-term investments and other 1.6%
Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time.
C000022594 [Member]  
Shareholder Report [Line Items]  
Fund Name Managed Volatility Balanced Portfolio
Class Name Series I
Trading Symbol JELBX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about the Managed Volatility Balanced Portfolio (the fund) for the period of 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 dfinview.com/johnhancock?site=funds. You can also request this information by contacting us at 800-344-1029 for John Hancock Variable Annuities and 800-732-5543 for John Hancock Variable Life Insurance.
Additional Information Phone Number 800-344-1029800-732-5543
Additional Information Website dfinview.com/johnhancock?site=funds
Expenses [Text Block]
What were the fund costs during the last six months ?
(Based on a hypothetical $10,000 investment)
Fund (Class) Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
Managed Volatility Balanced Portfolio
(Series I/JELBX)		 $11 0.22%
Expenses Paid, Amount $ 11
Expense Ratio, Percent 0.22%
Net Assets $ 3,852,027,730
Holdings Count | Holding 43
Investment Company Portfolio Turnover 59.00%
Additional Fund Statistics [Text Block]
Fund Statistics
Fund net assets $3,852,027,730
Total number of portfolio holdings 43
Portfolio turnover rate 59%
Holdings [Text Block]
Graphical Representation of Holdings
The table below shows the investment makeup of the fund, representing a percentage of the total net assets of the fund.
Asset Allocation
Affiliated investment companies 92.8%
Equity 49.2%
U.S. large cap 16.4%
Large blend 15.4%
International equity 7.8%
Emerging-market equity 4.2%
U.S. mid cap 3.8%
U.S. small cap 1.6%
Fixed income 40.3%
Intermediate bond 25.4%
Emerging-market debt 4.0%
High yield bond 3.5%
Bank loan 3.5%
Short-term bond 2.0%
Multi-sector bond 1.9%
Alternative and specialty 3.3%
Multi-asset income 1.9%
Sector equity 1.4%
U.S. Government 5.7%
Short-term investments and other 1.5%
Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time.
C000022595 [Member]  
Shareholder Report [Line Items]  
Fund Name Managed Volatility Balanced Portfolio
Class Name Series II
Trading Symbol JAJRX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about the Managed Volatility Balanced Portfolio (the fund) for the period of 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 dfinview.com/johnhancock?site=funds. You can also request this information by contacting us at 800-344-1029 for John Hancock Variable Annuities and 800-732-5543 for John Hancock Variable Life Insurance.
Additional Information Phone Number 800-344-1029800-732-5543
Additional Information Website dfinview.com/johnhancock?site=funds
Expenses [Text Block]
What were the fund costs during the last six months ?
(Based on a hypothetical $10,000 investment)
Fund (Class) Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
Managed Volatility Balanced Portfolio
(Series II/JAJRX)		 $21 0.42%
Expenses Paid, Amount $ 21
Expense Ratio, Percent 0.42%
Net Assets $ 3,852,027,730
Holdings Count | Holding 43
Investment Company Portfolio Turnover 59.00%
Additional Fund Statistics [Text Block]
Fund Statistics
Fund net assets $3,852,027,730
Total number of portfolio holdings 43
Portfolio turnover rate 59%
Holdings [Text Block]
Graphical Representation of Holdings
The table below shows the investment makeup of the fund, representing a percentage of the total net assets of the fund.
Asset Allocation
Affiliated investment companies 92.8%
Equity 49.2%
U.S. large cap 16.4%
Large blend 15.4%
International equity 7.8%
Emerging-market equity 4.2%
U.S. mid cap 3.8%
U.S. small cap 1.6%
Fixed income 40.3%
Intermediate bond 25.4%
Emerging-market debt 4.0%
High yield bond 3.5%
Bank loan 3.5%
Short-term bond 2.0%
Multi-sector bond 1.9%
Alternative and specialty 3.3%
Multi-asset income 1.9%
Sector equity 1.4%
U.S. Government 5.7%
Short-term investments and other 1.5%
Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time.
C000022593 [Member]  
Shareholder Report [Line Items]  
Fund Name Managed Volatility Balanced Portfolio
Class Name Series NAV
Trading Symbol JAIYX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about the Managed Volatility Balanced Portfolio (the fund) for the period of 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 dfinview.com/johnhancock?site=funds. You can also request this information by contacting us at 800-344-1029 for John Hancock Variable Annuities and 800-732-5543 for John Hancock Variable Life Insurance.
Additional Information Phone Number 800-344-1029800-732-5543
Additional Information Website dfinview.com/johnhancock?site=funds
Expenses [Text Block]
What were the fund costs during the last six months ?
(Based on a hypothetical $10,000 investment)
Fund (Class) Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
Managed Volatility Balanced Portfolio
(Series NAV/JAIYX)		 $9 0.17%
Expenses Paid, Amount $ 9
Expense Ratio, Percent 0.17%
Net Assets $ 3,852,027,730
Holdings Count | Holding 43
Investment Company Portfolio Turnover 59.00%
Additional Fund Statistics [Text Block]
Fund Statistics
Fund net assets $3,852,027,730
Total number of portfolio holdings 43
Portfolio turnover rate 59%
Holdings [Text Block]
Graphical Representation of Holdings
The table below shows the investment makeup of the fund, representing a percentage of the total net assets of the fund.
Asset Allocation
Affiliated investment companies 92.8%
Equity 49.2%
U.S. large cap 16.4%
Large blend 15.4%
International equity 7.8%
Emerging-market equity 4.2%
U.S. mid cap 3.8%
U.S. small cap 1.6%
Fixed income 40.3%
Intermediate bond 25.4%
Emerging-market debt 4.0%
High yield bond 3.5%
Bank loan 3.5%
Short-term bond 2.0%
Multi-sector bond 1.9%
Alternative and specialty 3.3%
Multi-asset income 1.9%
Sector equity 1.4%
U.S. Government 5.7%
Short-term investments and other 1.5%
Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time.
C000022598 [Member]  
Shareholder Report [Line Items]  
Fund Name Managed Volatility Moderate Portfolio
Class Name Series NAV
Trading Symbol JAIVX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about the Managed Volatility Moderate Portfolio (the fund) for the period of 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 dfinview.com/johnhancock?site=funds. You can also request this information by contacting us at 800-344-1029 for John Hancock Variable Annuities and 800-732-5543 for John Hancock Variable Life Insurance.
Additional Information Phone Number 800-344-1029800-732-5543
Additional Information Website dfinview.com/johnhancock?site=funds
Expenses [Text Block]
What were the fund costs during the last six months ?
(Based on a hypothetical $10,000 investment)
Fund (Class) Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
Managed Volatility Moderate Portfolio
(Series NAV/JAIVX)		 $11 0.22%
Expenses Paid, Amount $ 11
Expense Ratio, Percent 0.22%
Net Assets $ 958,497,181
Holdings Count | Holding 42
Investment Company Portfolio Turnover 64.00%
Additional Fund Statistics [Text Block]
Fund Statistics
Fund net assets $958,497,181
Total number of portfolio holdings 42
Portfolio turnover rate 64%
Holdings [Text Block]
Graphical Representation of Holdings
The table below shows the investment makeup of the fund, representing a percentage of the total net assets of the fund.
Asset Allocation
Affiliated investment companies 92.4%
Equity 39.0%
Large blend 12.5%
U.S. large cap 11.9%
International equity 7.2%
Emerging-market equity 3.2%
U.S. mid cap 2.8%
U.S. small cap 1.4%
Fixed income 50.1%
Intermediate bond 31.8%
Emerging-market debt 4.8%
Bank loan 4.3%
High yield bond 4.2%
Short-term bond 3.0%
Multi-sector bond 2.0%
Alternative and specialty 3.3%
Multi-asset income 2.0%
Sector equity 1.3%
U.S. Government 6.2%
Short-term investments and other 1.4%
Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time.
C000022600 [Member]  
Shareholder Report [Line Items]  
Fund Name Managed Volatility Moderate Portfolio
Class Name Series II
Trading Symbol JAIWX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about the Managed Volatility Moderate Portfolio (the fund) for the period of 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 dfinview.com/johnhancock?site=funds. You can also request this information by contacting us at 800-344-1029 for John Hancock Variable Annuities and 800-732-5543 for John Hancock Variable Life Insurance.
Additional Information Phone Number 800-344-1029800-732-5543
Additional Information Website dfinview.com/johnhancock?site=funds
Expenses [Text Block]
What were the fund costs during the last six months ?
(Based on a hypothetical $10,000 investment)
Fund (Class) Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
Managed Volatility Moderate Portfolio
(Series II/JAIWX)		 $24 0.47%
Expenses Paid, Amount $ 24
Expense Ratio, Percent 0.47%
Net Assets $ 958,497,181
Holdings Count | Holding 42
Investment Company Portfolio Turnover 64.00%
Additional Fund Statistics [Text Block]
Fund Statistics
Fund net assets $958,497,181
Total number of portfolio holdings 42
Portfolio turnover rate 64%
Holdings [Text Block]
Graphical Representation of Holdings
The table below shows the investment makeup of the fund, representing a percentage of the total net assets of the fund.
Asset Allocation
Affiliated investment companies 92.4%
Equity 39.0%
Large blend 12.5%
U.S. large cap 11.9%
International equity 7.2%
Emerging-market equity 3.2%
U.S. mid cap 2.8%
U.S. small cap 1.4%
Fixed income 50.1%
Intermediate bond 31.8%
Emerging-market debt 4.8%
Bank loan 4.3%
High yield bond 4.2%
Short-term bond 3.0%
Multi-sector bond 2.0%
Alternative and specialty 3.3%
Multi-asset income 2.0%
Sector equity 1.3%
U.S. Government 6.2%
Short-term investments and other 1.4%
Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time.
C000022599 [Member]  
Shareholder Report [Line Items]  
Fund Name Managed Volatility Moderate Portfolio
Class Name Series I
Trading Symbol JELMX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about the Managed Volatility Moderate Portfolio (the fund) for the period of 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 dfinview.com/johnhancock?site=funds. You can also request this information by contacting us at 800-344-1029 for John Hancock Variable Annuities and 800-732-5543 for John Hancock Variable Life Insurance.
Additional Information Phone Number 800-344-1029800-732-5543
Additional Information Website dfinview.com/johnhancock?site=funds
Expenses [Text Block]
What were the fund costs during the last six months ?
(Based on a hypothetical $10,000 investment)
Fund (Class) Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
Managed Volatility Moderate Portfolio
(Series I/JELMX)		 $14 0.27%
Expenses Paid, Amount $ 14
Expense Ratio, Percent 0.27%
Net Assets $ 958,497,181
Holdings Count | Holding 42
Investment Company Portfolio Turnover 64.00%
Additional Fund Statistics [Text Block]
Fund Statistics
Fund net assets $958,497,181
Total number of portfolio holdings 42
Portfolio turnover rate 64%
Holdings [Text Block]
Graphical Representation of Holdings
The table below shows the investment makeup of the fund, representing a percentage of the total net assets of the fund.
Asset Allocation
Affiliated investment companies 92.4%
Equity 39.0%
Large blend 12.5%
U.S. large cap 11.9%
International equity 7.2%
Emerging-market equity 3.2%
U.S. mid cap 2.8%
U.S. small cap 1.4%
Fixed income 50.1%
Intermediate bond 31.8%
Emerging-market debt 4.8%
Bank loan 4.3%
High yield bond 4.2%
Short-term bond 3.0%
Multi-sector bond 2.0%
Alternative and specialty 3.3%
Multi-asset income 2.0%
Sector equity 1.3%
U.S. Government 6.2%
Short-term investments and other 1.4%
Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time.
C000022604 [Member]  
Shareholder Report [Line Items]  
Fund Name Managed Volatility Conservative Portfolio
Class Name Series I
Trading Symbol JELCX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about the Managed Volatility Conservative Portfolio (the fund) for the period of 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 dfinview.com/johnhancock?site=funds. You can also request this information by contacting us at 800-344-1029 for John Hancock Variable Annuities and 800-732-5543 for John Hancock Variable Life Insurance.
Additional Information Phone Number 800-344-1029800-732-5543
Additional Information Website dfinview.com/johnhancock?site=funds
Expenses [Text Block]
What were the fund costs during the last six months ?
(Based on a hypothetical $10,000 investment)
Fund (Class) Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
Managed Volatility Conservative Portfolio
(Series I/JELCX)		 $16 0.31%
Expenses Paid, Amount $ 16
Expense Ratio, Percent 0.31%
Net Assets $ 445,711,231
Holdings Count | Holding 35
Investment Company Portfolio Turnover 73.00%
Additional Fund Statistics [Text Block]
Fund Statistics
Fund net assets $445,711,231
Total number of portfolio holdings 35
Portfolio turnover rate 73%
Holdings [Text Block]
Graphical Representation of Holdings
The table below shows the investment makeup of the fund, representing a percentage of the total net assets of the fund.
Asset Allocation
Affiliated investment companies 89.1%
Equity 20.2%
Large blend 6.2%
U.S. large cap 6.0%
International equity 4.0%
Emerging-market equity 1.4%
U.S. mid cap 1.4%
U.S. small cap 1.2%
Fixed income 66.4%
Intermediate bond 42.0%
Emerging-market debt 6.2%
Bank loan 5.9%
High yield bond 5.8%
Short-term bond 4.0%
Multi-sector bond 2.5%
Alternative and specialty 2.5%
Multi-asset income 2.5%
U.S. Government 10.0%
Short-term investments and other 0.9%
Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time.
C000022605 [Member]  
Shareholder Report [Line Items]  
Fund Name Managed Volatility Conservative Portfolio
Class Name Series II
Trading Symbol JAISX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about the Managed Volatility Conservative Portfolio (the fund) for the period of 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 dfinview.com/johnhancock?site=funds. You can also request this information by contacting us at 800-344-1029 for John Hancock Variable Annuities and 800-732-5543 for John Hancock Variable Life Insurance.
Additional Information Phone Number 800-344-1029800-732-5543
Additional Information Website dfinview.com/johnhancock?site=funds
Expenses [Text Block]
What were the fund costs during the last six months ?
(Based on a hypothetical $10,000 investment)
Fund (Class) Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
Managed Volatility Conservative Portfolio
(Series II/JAISX)		 $26 0.51%
Expenses Paid, Amount $ 26
Expense Ratio, Percent 0.51%
Net Assets $ 445,711,231
Holdings Count | Holding 35
Investment Company Portfolio Turnover 73.00%
Additional Fund Statistics [Text Block]
Fund Statistics
Fund net assets $445,711,231
Total number of portfolio holdings 35
Portfolio turnover rate 73%
Holdings [Text Block]
Graphical Representation of Holdings
The table below shows the investment makeup of the fund, representing a percentage of the total net assets of the fund.
Asset Allocation
Affiliated investment companies 89.1%
Equity 20.2%
Large blend 6.2%
U.S. large cap 6.0%
International equity 4.0%
Emerging-market equity 1.4%
U.S. mid cap 1.4%
U.S. small cap 1.2%
Fixed income 66.4%
Intermediate bond 42.0%
Emerging-market debt 6.2%
Bank loan 5.9%
High yield bond 5.8%
Short-term bond 4.0%
Multi-sector bond 2.5%
Alternative and specialty 2.5%
Multi-asset income 2.5%
U.S. Government 10.0%
Short-term investments and other 0.9%
Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time.
C000022603 [Member]  
Shareholder Report [Line Items]  
Fund Name Managed Volatility Conservative Portfolio
Class Name Series NAV
Trading Symbol JAIUX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about the Managed Volatility Conservative Portfolio (the fund) for the period of 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 dfinview.com/johnhancock?site=funds. You can also request this information by contacting us at 800-344-1029 for John Hancock Variable Annuities and 800-732-5543 for John Hancock Variable Life Insurance.
Additional Information Phone Number 800-344-1029800-732-5543
Additional Information Website dfinview.com/johnhancock?site=funds
Expenses [Text Block]
What were the fund costs during the last six months ?
(Based on a hypothetical $10,000 investment)
Fund (Class) Costs of a $10,000 investment Costs paid as a percentage
of a $10,000 investment
Managed Volatility Conservative Portfolio
(Series NAV/JAIUX)		 $13 0.26%
Expenses Paid, Amount $ 13
Expense Ratio, Percent 0.26%
Net Assets $ 445,711,231
Holdings Count | Holding 35
Investment Company Portfolio Turnover 73.00%
Additional Fund Statistics [Text Block]
Fund Statistics
Fund net assets $445,711,231
Total number of portfolio holdings 35
Portfolio turnover rate 73%
Holdings [Text Block]
Graphical Representation of Holdings
The table below shows the investment makeup of the fund, representing a percentage of the total net assets of the fund.
Asset Allocation
Affiliated investment companies 89.1%
Equity 20.2%
Large blend 6.2%
U.S. large cap 6.0%
International equity 4.0%
Emerging-market equity 1.4%
U.S. mid cap 1.4%
U.S. small cap 1.2%
Fixed income 66.4%
Intermediate bond 42.0%
Emerging-market debt 6.2%
Bank loan 5.9%
High yield bond 5.8%
Short-term bond 4.0%
Multi-sector bond 2.5%
Alternative and specialty 2.5%
Multi-asset income 2.5%
U.S. Government 10.0%
Short-term investments and other 0.9%
Holdings may not have been held by the fund for the entire period and are subject to change without notice. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk and may change at any time.