v3.25.1
Label Element Value
Prospectus [Line Items] rr_ProspectusLineItems  
Document Type dei_DocumentType 485BPOS
Document Period End Date dei_DocumentPeriodEndDate Dec. 31, 2024
Entity Registrant Name dei_EntityRegistrantName JNL INVESTORS SERIES TRUST
Entity Central Index Key dei_EntityCentralIndexKey 0001121257
Entity Inv Company Type dei_EntityInvCompanyType N-1A
Amendment Flag dei_AmendmentFlag false
Document Creation Date dei_DocumentCreationDate Apr. 24, 2025
Document Effective Date dei_DocumentEffectiveDate Apr. 28, 2025
Prospectus Date rr_ProspectusDate Apr. 28, 2025
JNL Government Money Market Fund  
Prospectus [Line Items] rr_ProspectusLineItems  
Objective [Heading] rr_ObjectiveHeading Investment Objective.
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The investment objective of the Fund is to achieve as high a level of current income as is consistent with the preservation of capital and maintenance of liquidity.

 

Expense [Heading] rr_ExpenseHeading Expenses.
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund.

 

You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.

 

Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder Fees (fees paid directly from your investment) Not Applicable
Operating Expenses Caption [Text] rr_OperatingExpensesCaption Annual Fund Operating Expenses (Expenses that you pay each year as a percentage of the value of your investment)
Expense Example [Heading] rr_ExpenseExampleHeading Expense Example.
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The table below shows the expenses you would pay on a $10,000 investment, assuming (1) 5% annual return; (2) redemption at the end of each time period; and (3) that the Fund operating expenses remain the same. The example also assumes that the Class SL administrative fee waiver is discontinued after one year. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

 

Strategy [Heading] rr_StrategyHeading Principal Investment Strategies.
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

Under normal circumstances, the Fund seeks to achieve its investment objective by investing at least 99.5% of its total assets in cash, U.S. Government securities, and/or repurchase agreements that are “collateralized fully” (i.e., collateralized by cash or government securities). The government securities typically have a maximum remaining maturity of 397 calendar days and the repurchase agreements are collateralized by cash or government securities. Under normal circumstances, the Fund will invest at least 80% of its assets (net assets plus the amount of any borrowings made for investment purposes) in government securities or repurchase agreements collateralized by government securities. As a government money market fund, the Fund is exempt from requirements that permit money market funds to impose a liquidity fee. While the Fund’s Board of Trustees may elect to subject the Fund to liquidity fee requirements in the future, the Board of Trustees has not elected to do so at this time.

 

The Fund seeks to maintain a stable net asset value of $1.00 per share, neither the Federal Deposit Insurance Company, nor any other government agency insures or protects your investment.

 

Risk [Heading] rr_RiskHeading Principal Risks of Investing in the Fund.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading Performance.
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The performance information shown provides some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and by showing how the Fund’s average annual returns compared with those of a broad-based securities market index and an additional index that the Adviser believes more closely reflects the market segments in which the Fund invests. Performance results include the effect of expense waiver/reduction arrangements for some or all of the periods shown. If such arrangements had not been in place, performance for those periods would have been lower. The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future.

 

Prior to September 19, 2016, the Fund was operated as a prime money market fund. Effective September 19, 2016, the Fund operates as a government money market fund and, as such, invests at least 99.5% of its total assets in cash, government securities and/or repurchase agreements that are “collateralized fully” (i.e., backed by cash or government securities). Performance prior to February 1, 2024 reflects the Fund’s results when managed by the former sub-adviser, Wellington Management Company LLP.

 

Effective December 31, 2024, for consistency with the Fund’s principal investment strategies, the Fund added the Bloomberg U.S. Aggregate Index as the Fund’s primary benchmark and the Bloomberg USD 1 Month Cash Deposit Index as the Fund’s secondary benchmark.

 

The 7-day yield of the Class I (formerly named Institutional Class) on December 31, 2024, was 4.36%.

 

The 7-day yield of the Class SL on December 31, 2024, was 4.46%.

 

Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The performance information shown provides some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and by showing how the Fund’s average annual returns compared with those of a broad-based securities market index and an additional index that the Adviser believes more closely reflects the market segments in which the Fund invests. Performance results include the effect of expense waiver/reduction arrangements for some or all of the periods shown.
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading Annual Total Returns as of December 31
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

 

Best Quarter (ended 12/31/2023): 1.32%; Worst Quarter (ended 3/31/2022): 0.00%

Best Quarter (ended 3/31/2024): 1.32%; Worst Quarter (ended 12/31/2024): 1.18%

Performance Table Heading rr_PerformanceTableHeading Average Annual Total Returns as of 12/31/2024
JNL Government Money Market Fund | Risk Lose Money [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock You could lose money by investing in the Fund.
JNL Government Money Market Fund | Risk Money Market Fund May Not Preserve Dollar [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so.
JNL Government Money Market Fund | Risk Not Insured [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock An investment in the Fund is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
JNL Government Money Market Fund | Risk Money Market Fund Sponsor May Not Provide Support [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock The Fund’s sponsor is not required to reimburse the Fund for losses, and you should not expect that the sponsor will provide financial support to the Fund at any time, including during periods of market stress.
JNL Government Money Market Fund | Fixed-income risk [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock
Fixed-income risk The price of fixed-income securities responds to economic developments, particularly interest rate changes, as well as to perceptions about the credit risk of individual issuers. Rising interest rates generally will cause the price of bonds and other fixed-income debt securities to fall. Falling interest rates may cause an issuer to redeem, call or refinance a security before its stated maturity, which may result in the Fund having to reinvest the proceeds in lower yielding securities. Bonds and other fixed-income debt securities are subject to credit risk, which is the possibility that the credit strength of an issuer will weaken and/or an issuer of a fixed-income security will fail to make timely payments of principal or interest and the security will go into default. Debt instruments typically do not provide any voting rights, except in cases when interest payments have not been made and the issuer is in default.

 

JNL Government Money Market Fund | Income risk [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock
Income risk – The Fund is subject to the risk that the income generated from the Fund’s investments may decline in the event of falling interest rates. Income risk may be high if the Fund’s income is predominantly based on short-term interest rates, which can fluctuate significantly over short periods. The Fund’s distributions to shareholders may decline when interest rates fall.

 

JNL Government Money Market Fund | Interest rate risk [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock
Interest rate risk When interest rates increase, fixed-income securities generally will decline in value. Long-term fixed income securities normally have more price volatility than short-term fixed income securities. The value of certain equity investments, such as utilities and real estate-related securities, may also be sensitive to interest rate changes.

 

JNL Government Money Market Fund | Repurchase agreements, purchase and sale contracts risk [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock
Repurchase agreements, purchase and sale contracts risk – If the other party to a repurchase agreement or purchase and sale contract defaults on its obligation under the agreement, the Fund may suffer delays and incur costs or lose money in exercising its rights under the agreement. If the seller fails to repurchase the security under a repurchase agreement or purchase and sale contract, and the market value of the security declines, the Fund may lose money.

 

JNL Government Money Market Fund | U.S. Government securities risk [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock
U.S. Government securities risk – Obligations issued by agencies and instrumentalities of the U.S. Government vary in the level of support they receive from the U.S. Government. They may be: (i) supported by the full faith and credit of the U.S. Treasury; (ii) supported by the right of the issuer to borrow from the U.S. Treasury; (iii) supported by the discretionary authority of the U.S. Government to purchase the issuer’s obligations; or (iv) supported only by the credit of the issuer. The maximum potential liability of the issuers of some U.S. Government securities may greatly exceed their current resources, or their legal right to receive support from the U.S. Treasury.


 

JNL Government Money Market Fund | Class I  
Prospectus [Line Items] rr_ProspectusLineItems  
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.08%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.11% [1]
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 0.19%
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 19
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 61
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 107
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 243
Annual Return 2015 rr_AnnualReturn2015 0.05%
Annual Return 2016 rr_AnnualReturn2016 0.25%
Annual Return 2017 rr_AnnualReturn2017 0.73%
Annual Return 2018 rr_AnnualReturn2018 1.71%
Annual Return 2019 rr_AnnualReturn2019 2.08%
Annual Return 2020 rr_AnnualReturn2020 0.34%
Annual Return 2021 rr_AnnualReturn2021 0.01%
Annual Return 2022 rr_AnnualReturn2022 1.31%
Annual Return 2023 rr_AnnualReturn2023 4.92%
Annual Return 2024 rr_AnnualReturn2024 5.13%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Dec. 31, 2023
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 1.32%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Mar. 31, 2022
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn none
1 Year rr_AverageAnnualReturnYear01 5.13%
5 Years rr_AverageAnnualReturnYear05 2.32%
10 Years rr_AverageAnnualReturnYear10 1.64%
Money Market Seven Day Yield, Caption [Text] rr_MoneyMarketSevenDayYieldCaption The 7-day yield of the Class I (formerly named Institutional Class) on December 31, 2024,
Money Market Seven Day Yield rr_MoneyMarketSevenDayYield 4.36%
JNL Government Money Market Fund | Class I | Bloomberg U.S. Aggregate Index (reflects no deduction for fees, expenses, or taxes)  
Prospectus [Line Items] rr_ProspectusLineItems  
1 Year rr_AverageAnnualReturnYear01 1.25%
5 Years rr_AverageAnnualReturnYear05 (0.33%)
10 Years rr_AverageAnnualReturnYear10 1.35%
JNL Government Money Market Fund | Class I | Bloomberg USD 1 Month Cash Deposit Index SPLICE (reflects no deduction for fees, expenses, or taxes)  
Prospectus [Line Items] rr_ProspectusLineItems  
1 Year rr_AverageAnnualReturnYear01 5.40% [2]
5 Years rr_AverageAnnualReturnYear05 2.53% [2]
10 Years rr_AverageAnnualReturnYear10 1.77% [2]
JNL Government Money Market Fund | Class SL  
Prospectus [Line Items] rr_ProspectusLineItems  
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.08%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.11% [3]
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 0.19%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.10%) [4]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 0.09%
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 9
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 51
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 97
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 233
Annual Return 2024 rr_AnnualReturn2024 5.25%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Mar. 31, 2024
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 1.32%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2024
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn 1.18%
1 Year rr_AverageAnnualReturnYear01 5.25%
Since Inception rr_AverageAnnualReturnSinceInception 5.25%
Inception Date rr_AverageAnnualReturnInceptionDate May 01, 2023
Money Market Seven Day Yield, Caption [Text] rr_MoneyMarketSevenDayYieldCaption The 7-day yield of the Class SL on December 31, 2024,
Money Market Seven Day Yield rr_MoneyMarketSevenDayYield 4.46%
JNL Government Money Market Fund | Class SL | Bloomberg U.S. Aggregate Index (reflects no deduction for fees, expenses, or taxes)  
Prospectus [Line Items] rr_ProspectusLineItems  
1 Year rr_AverageAnnualReturnYear01 1.25%
Since Inception rr_AverageAnnualReturnSinceInception 1.87%
JNL Government Money Market Fund | Class SL | Bloomberg USD 1 Month Cash Deposit Index SPLICE (reflects no deduction for fees, expenses, or taxes)  
Prospectus [Line Items] rr_ProspectusLineItems  
1 Year rr_AverageAnnualReturnYear01 5.40% [5]
Since Inception rr_AverageAnnualReturnSinceInception 5.42% [5]
[1] “Other Expenses” include an Administrative Fee of 0.10% which is payable to Jackson National Asset Management, LLC (“JNAM” or “Adviser”).
[2] Index performance through December 30, 2020 reflects the performance of the FTSE U.S. Treasury Bill Index (1-month). Index performance beginning December 31, 2020 reflects the performance of the Bloomberg USD 1 Month Cash Deposit Index SPLICE.
[3] “Other Expenses” include an Administrative Fee of 0.10% which is payable to Jackson National Asset Management, LLC (“JNAM” or “Adviser”).
[4] JNAM has contractually agreed to waive 100.00% of the administrative fees of the Class.  The fee waiver will continue for at least one year from the date of the current Prospectus, and continue thereafter unless the Board of Trustees approves a change in or elimination of the waiver. This fee waiver is subject to yearly review and approval by the Board of Trustees.
[5] Index performance through December 30, 2020 reflects the performance of the FTSE U.S. Treasury Bill Index (1-month). Index performance beginning December 31, 2020 reflects the performance of the Bloomberg USD 1 Month Cash Deposit Index SPLICE.