Label	Element	Value
Risk Return Abstract	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	JOHN HANCOCK STRATEGIC SERIES
Prospectus Date	rr_ProspectusDate	Oct. 01, 2023
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio
Risk Return Abstract	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<span style="color:#000000;font-family:Arial;font-size:30pt;">John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio</span>
Objective [Heading]	rr_ObjectiveHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Investment objective</span>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	To seek high level of current income consistent with prudent investment risk.
Expense [Heading]	rr_ExpenseHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Fees and expenses</span>
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses 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.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<span style="font-family:Arial;font-size:8pt;font-weight:bold;margin-left:0.0pt;">Annual fund operating expenses (%) </span><span style="font-family:Arial;font-size:8pt;margin-left:0.0pt;">(expenses that you pay each year as a percentage of the value of your investment)</span>
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	<span style="font-family:Arial;font-size:8pt;">September 30, </span><span style="font-family:Arial;font-size:8pt;">2024</span>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Portfolio turnover</span>
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During its most recent fiscal year, the fund’s portfolio turnover rate was 87% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	87.00%
Expense Example [Heading]	rr_ExpenseExampleHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Expense example</span>
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. Please see below a hypothetical example showing the expenses of a $10,000 investment for the time periods indicated and then assuming you sell all of your shares at the end of those periods. The example assumes a 5% average annual return and that fund expenses will not change over the periods. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Principal investment strategies</span>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Under normal market conditions, the fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in a diversified portfolio of bonds. These may include, but are not limited to, below-investment-grade debt securities (junk bonds) rated as low as CC by S&P Global Ratings (S&P) and Ca by Moody’s Investors Service, Inc. (Moody’s), or their unrated equivalents. The fund will not invest in investment-grade securities. The fund’s investment policies are based on credit ratings at the time of purchase. There is no limit on average maturity. The manager focuses on sector allocation, industry allocation, and security selection in making investment decisions. When making sector and industry allocations, the manager uses top-down analysis to try to anticipate and react to shifts in the business cycle. The manager uses bottom-up research to find individual securities that appear comparatively undervalued.The manager considers environmental, social, and/or governance (ESG) factors, alongside other relevant factors, as part of its investment process. ESG factors may include, but are not limited to, matters regarding board diversity, climate change policies, and supply chain and human rights policies. The ESG characteristics utilized in the fund’s investment process may change over time and one or more characteristics may not be relevant with respect to all issuers that are eligible fund investments.The fund may invest in securities of foreign governments and corporations. The fund will not invest more than 10% of its total assets in securities denominated in foreign currencies.Under normal market conditions, the fund does not anticipate investing more than 25% of its total assets in U.S. dollar-denominated foreign securities (excluding Canadian securities). The fund may engage in derivatives transactions, including credit default swaps, foreign currency forward contracts, futures contracts, and options, to reduce risk, obtain efficient market exposure, and/or enhance investment returns. The fund may trade securities actively. The fund may invest in bonds issued by master limited partnerships.
Risk [Heading]	rr_RiskHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Principal risks</span>
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Past performance</span>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following information illustrates the variability of the fund’s returns and 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 a broad-based market index.Past performance (before and after taxes) does not indicate future results. All figures assume dividend reinvestment. Performance information is updated daily, monthly, and quarterly and may be obtained at our website, jhinvestments.com, or by calling 800-247-0278, Monday to Thursday, 8:00 a.m.—7:00 p.m., and Friday, 8:00 a.m.—6:00 p.m., Eastern time.Please note that after-tax returns reflect the highest individual federal marginal income-tax rate in effect as of the date provided and do not reflect any state or local taxes. Your actual after-tax returns may be different. After-tax returns are not relevant to shares held in an IRA, 401(k), or other tax-advantaged investment plan.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	<span style="font-family:Arial;font-size:9pt;">The following information illustrates the variability of the fund’s returns and 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 a broad-based market index.</span>
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	<span style="font-family:Arial;font-size:9pt;">800-247-0278</span>
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	<span style="font-family:Arial;font-size:9pt;">jhinvestments.com</span>
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	<span style="font-family:Arial;font-size:9pt;">Past performance (before and after taxes) does not indicate future results.</span>
Bar Chart [Heading]	rr_BarChartHeading	<span style="font-family:Arial;font-size:9pt;font-weight:bold;">Calendar year total returns (%)</span>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Year-to-date total return through:Q2 20233.51%Best quarter:Q2 202011.89%Worst quarter:Q1 2020-15.15%
Performance Table Heading	rr_PerformanceTableHeading	<span style="font-family:Arial;font-size:8pt;font-weight:bold;margin-left:0.0pt;">Average annual total returns (%)—as of 12/31/2022</span>
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	<span style="color:#000000;font-family:Arial;font-size:9pt;">Please note that after-tax returns reflect the highest individual federal marginal income-tax rate in effect as of the date provided and do not reflect any state or local taxes.</span>
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	<span style="color:#000000;font-family:Arial;font-size:9pt;"> Your actual after-tax returns may be different. After-tax returns are not relevant to shares held in an IRA, 401(k), or other </span><span style="color:#000000;font-family:Arial;font-size:9pt;">tax-advantaged investment plan.</span>
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Risk Lose Money [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Risk Not Insured Depository Institution [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Changing Distribution Levels Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Changing distribution levels risk.  The fund may cease or reduce the level of its distribution if income or dividends paid from its investments declines.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Credit And Counterparty Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Credit and counterparty risk.  The issuer or guarantor of a fixed-income security, the counterparty to an over-the-counter derivatives contract, or a borrower of fund securities may not make timely payments or otherwise honor its obligations. A downgrade or default affecting any of the fund’s securities could affect the fund’s performance.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Economic And Market Events Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Economic and market events risk.  Events in the U.S. and global financial markets, including actions taken by the U.S. Federal Reserve or foreign central banks to stimulate or stabilize economic growth, may at times result in unusually high market volatility, which could negatively impact performance. Reduced liquidity in credit and fixed-income markets could adversely affect issuers worldwide. Banks and financial services companies could suffer losses if interest rates rise or economic conditions deteriorate.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | ESG Integration Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	ESG integration risk.  The manager considers ESG factors that it deems relevant or additive, along with other material factors and analysis, when managing the fund. ESG factors may include, but are not limited to, matters regarding board diversity, climate change policies, and supply chain and human rights policies. The manager may consider these ESG factors on all or a meaningful portion of the fund’s investments. Incorporating ESG criteria and making investment decisions based on certain ESG characteristics, as determined by the manager, carries the risk that the fund may perform differently, including underperforming, funds that do not utilize ESG criteria, or funds that utilize different ESG criteria.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Fixed Income Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Fixed-income securities risk.  A rise in interest rates typically causes bond prices to fall. The longer the average maturity or duration of the bonds held by a fund, the more sensitive it will likely be to interest-rate fluctuations. An issuer may not make all interest payments or repay all or any of the principal borrowed. Changes in a security’s credit quality may adversely affect fund performance.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Foreign Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Foreign securities risk.  Less information may be publicly available regarding foreign issuers, including foreign government issuers. Foreign securities may be subject to foreign taxes and may be more volatile than U.S. securities. Currency fluctuations and political and economic developments may adversely impact the value of foreign securities. If applicable, depositary receipts are subject to most of the risks associated with investing in foreign securities directly because the value of a depositary receipt is dependent upon the market price of the underlying foreign equity security. Depositary receipts are also subject to liquidity risk.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Hedging Derivatives And Other Strategic Transactions Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Hedging, derivatives, and other strategic transactions risk.  Hedging, derivatives, and other strategic transactions may increase a fund’s volatility and could produce disproportionate losses, potentially more than the fund’s principal investment. Risks of these transactions are different from and possibly greater than risks of investing directly in securities and other traditional instruments. Under certain market conditions, derivatives could become harder to value or sell and may become subject to liquidity risk (i.e., the inability to enter into closing transactions). Derivatives and other strategic transactions that the fund intends to utilize include: futures contracts, credit default swaps, foreign currency forward contracts, inverse floating-rate securities, options on futures, and options. Foreign currency forward contracts, futures contracts, options, and swaps generally are subject to counterparty risk. In addition, swaps may be subject to interest-rate and settlement risk, and the risk of default of the underlying reference obligation. Derivatives associated with foreign currency transactions are subject to currency risk.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | High Portfolio Turnover Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	High portfolio turnover risk.  Trading securities actively and frequently can increase transaction costs (thus lowering performance) and taxable distributions.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Liquidity Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Liquidity risk.  The extent (if at all) to which a security may be sold or a derivative position closed without negatively impacting its market value may be impaired by reduced market activity or participation, legal restrictions, or other economic and market impediments. Liquidity risk may be magnified in rising interest rate environments due to higher than normal redemption rates. Widespread selling of fixed-income securities to satisfy redemptions during periods of reduced demand may adversely impact the price or salability of such securities. Periods of heavy redemption could cause the fund to sell assets at a loss or depressed value, which could negatively affect performance. Redemption risk is heightened during periods of declining or illiquid markets.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Lower Rated And High Yield Fixed Income Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Lower-rated and high-yield fixed-income securities risk.  Lower-rated and high-yield fixed-income securities (junk bonds) are subject to greater credit quality risk, risk of default, and price volatility than higher-rated fixed-income securities, may be considered speculative, and can be difficult to resell.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Master Limited Partnership Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Master limited partnership (MLP) risk.  MLPs generally reflect the risks associated with their underlying assets and with pooled investment vehicles. MLPs with credit-related holdings are subject to interest-rate risk and risk of default.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Operational And Cybersecurity Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Operational and cybersecurity risk.  Cybersecurity breaches may allow an unauthorized party to gain access to fund assets, customer data, or proprietary information, or cause a fund or its service providers to suffer data corruption or lose operational functionality. Similar incidents affecting issuers of a fund’s securities may negatively impact performance. Operational risk may arise from human error, error by third parties, communication errors, or technology failures, among other causes.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Sector Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Sector risk.  When a fund focuses its investments in certain sectors of the economy, its performance may be driven largely by sector performance and could fluctuate more widely than if the fund were invested more evenly across sectors.
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | N/A
Risk Return Abstract	rr_RiskReturnAbstract
Maximum Cumulative Sales Charge (as a percentage)	rr_MaximumCumulativeSalesChargeOverOther	none
Maximum deferred sales charge (load)	rr_MaximumDeferredSalesChargeOverOther	none
Management fee	rr_ManagementFeesOverAssets	0.63%
Other expenses	rr_OtherExpensesOverAssets	0.35%
Total annual fund operating expenses	rr_ExpensesOverAssets	0.98%
Contractual expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.98%)	[1]
Total annual fund operating expenses after expense reimbursements	rr_NetExpensesOverAssets	none
1 year	rr_ExpenseExampleYear01	none
3 years	rr_ExpenseExampleYear03	214
5 years	rr_ExpenseExampleYear05	446
10 years	rr_ExpenseExampleYear10	$ 1,112
2020	rr_AnnualReturn2020	5.32%
2021	rr_AnnualReturn2021	4.26%
2022	rr_AnnualReturn2022	(11.64%)
Year to Date Return, Label	rr_YearToDateReturnLabel	<span style="font-family:Arial;font-size:8pt;font-weight:bold;margin-left:0.0pt;">Year-to-date total return through:</span>
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Jun. 30, 2023
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	3.51%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	<span style="font-family:Arial;font-size:8pt;font-weight:bold;margin-left:0.0pt;">Best quarter:</span>
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2020
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	11.89%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	<span style="font-family:Arial;font-size:8pt;font-weight:bold;margin-left:0.0pt;">Worst quarter:</span>
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Mar. 31, 2020
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(15.15%)
1 year	rr_AverageAnnualReturnYear01	(11.64%)
Since Inception	rr_AverageAnnualReturnSinceInception	0.07%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jul. 09, 2019
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Return After Taxes on Distributions | N/A
Risk Return Abstract	rr_RiskReturnAbstract
1 year	rr_AverageAnnualReturnYear01	(13.96%)
Since Inception	rr_AverageAnnualReturnSinceInception	(2.37%)
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | Return After Taxes on Distributions and Sale of Shares | N/A
Risk Return Abstract	rr_RiskReturnAbstract
1 year	rr_AverageAnnualReturnYear01	(6.87%)
Since Inception	rr_AverageAnnualReturnSinceInception	(0.91%)
John Hancock Managed Account Shares Non-Investment-Grade Corporate Bond Portfolio | ICE Bank of America U.S. High Yield Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
1 year	rr_AverageAnnualReturnYear01	(11.22%)
Since Inception	rr_AverageAnnualReturnSinceInception	0.85%

[1] The advisor has contractually agreed to reimburse 100% of the fund’s operating expenses, including the Management fee, excluding (a) taxes, (b) brokerage commissions, (c) interest expense, (d) litigation and indemnification expenses and other extraordinary expenses not incurred in the ordinary course of the fund’s business, (e) borrowing costs and (f) acquired fund fees and expenses paid indirectly. This agreement expires on September 30, 2024, unless renewed by mutual agreement of the fund and the advisor based upon a determination that this is appropriate under the circumstances at that time. The fund is an integral part of a separately managed account program, and the fund’s manager, the fund’s subadvisor or their affiliates will be compensated directly or indirectly by separately managed account program sponsors or program participants for managed account advisory services. Participants in a separately managed account program pay a “wrap” fee to the sponsor of the program. Participants pay no additional fees or expenses to purchase shares of the fund.