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Label Element Value
Prospectus: rr_ProspectusTable  
Document Type dei_DocumentType 485BPOS
Document Period End Date dei_DocumentPeriodEndDate Jun. 30, 2016
Entity Registrant Name dei_EntityRegistrantName TOUCHSTONE STRATEGIC TRUST
Central Index Key dei_EntityCentralIndexKey 0000711080
Amendment Flag dei_AmendmentFlag false
Document Creation Date dei_DocumentCreationDate Oct. 28, 2016
Document Effective Date dei_DocumentEffectiveDate Oct. 28, 2016
Prospectus Date rr_ProspectusDate Oct. 30, 2016
TOUCHSTONE STRATEGIC TRUST | Touchstone Credit Opportunities Fund  
Prospectus: rr_ProspectusTable  
Risk/Return [Heading] rr_RiskReturnHeading TOUCHSTONE CREDIT OPPORTUNITIES FUND SUMMARY
Objective [Heading] rr_ObjectiveHeading The Fund’s Investment Goal
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock
The Touchstone Credit Opportunities Fund (the “Fund”) seeks absolute total return, primarily from income and capital appreciation.
Expense [Heading] rr_ExpenseHeading The Fund’s Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock
This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts for Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 or more in the Touchstone Funds. More information about these and other discounts is available from your financial professional, in the section entitled “Choosing a Class of Shares” in the Fund’s prospectus and Statement of Additional Information ("SAI") on page 60 and 77, respectively, and, in Appendix A — Intermediary-Specific Sales Charge Waivers and Discounts to the Fund's prospectus.
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder Fees (fees paid directly from your investment)
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)
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading Portfolio Turnover.
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock
The Fund pays transaction costs, such as brokerage 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 the most recent fiscal year, the Fund's portfolio turnover rate was 84% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 84.00%
Expense Breakpoint Discounts [Text] rr_ExpenseBreakpointDiscounts You may qualify for sales charge discounts for Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 or more in the Touchstone Funds.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount $ 50,000
Expense Example [Heading] rr_ExpenseExampleHeading 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 example assumes that you invest $10,000 in the Fund for the time periods indicated and then, except as indicated, redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, that the Fund’s operating expenses remain the same and that all fee waivers or expense limits for the Fund will expire after one year. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption Assuming Redemption at End of Period
Expense Example, No Redemption, By Year, Caption [Text] rr_ExpenseExampleNoRedemptionByYearCaption Assuming No Redemption
Strategy [Heading] rr_StrategyHeading The Fund’s Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock
The Fund invests, under normal circumstances, at least 80% of its assets (including the amount of borrowings for investment purposes) in U.S. and non-U.S. debt instruments.
 
The Fund seeks to achieve its investment goal by investing in a wide array of debt securities or other debt instruments. The Fund may invest in debt instruments of any credit quality or rating and may invest without limit in loans, bonds and other debt instruments that are rated below investment grade by one or more nationally recognized statistical ratings organizations (“NRSRO”) (i.e., rated Ba or lower by Moody’s Investors Service, Inc. (“Moody’s”) or BB or lower by Standard & Poor’s Ratings Services (“S&P”)) or, if unrated, deemed by the Fund’s sub-advisor, Ares Capital Management II, LLC (“Ares” or the "Sub-Advisor"), to be of comparable quality.  These investments may include distressed or defaulted debt instruments.  Securities rated below investment grade are sometimes referred to as “high yield” or “junk” bonds.
 
In managing the Fund’s portfolio, Ares seeks to take advantage of opportunities presented from time to time in credit markets by systematically allocating and reallocating the Fund’s assets among core investments and opportunistic investments as credit market conditions change.
 
The Fund’s core investments include the following:
 
•
Opportunistic Liquid Credit—The Fund seeks to generate current income with attractive relative value by investing in senior secured and unsecured debt of U.S. and non-U.S. companies.
•
Structured Credit—The Fund seeks to generate current income and capital appreciation by investing in debt and equity securities of Collateralized Loan Obligations in the U.S. and globally.
•
Special Situations—The Fund seeks capital appreciation by investing in distressed U.S. and non-U.S. corporate loans and bonds that trade at significant discounts to par value.
•
Hedges—The Fund engages in short selling, futures contracts, total return and interest rate swaps, pairs trades and options transactions in an attempt to achieve downside protection and reduce portfolio volatility.
 
The Fund may also invest in securities that may be offered and sold to only qualified institutional buyers under Rule 144A of the 1933 Act.

In addition, the Fund may make opportunistic investments from time to time in stressed and distressed securities, including debtor-in-possession loans (sometimes referred to as “DIP” loans), exit financings, rescue financings, and post-bankruptcy equity securities, as well as preferred stock, convertible debt, and other securitized vehicles.
 
The corporate loans (commonly referred to as “bank loans”) in which the Fund invests are typically senior in payment priority and secured by a lien on the borrower’s assets.  These corporate loans may include second lien loans, mezzanine loans and, to a limited extent, DIP loans.  The capacity of a company to borrow and the quality of the credit underlying a corporate loan are typically determined based upon one or more of the projected cash flows of the borrower, the enterprise value of the borrower or the asset value of the collateral supporting any liens.

The corporate debt securities, including high yield bonds, and other similar debt instruments in which the Fund invests are typically unsecured and may be subordinated in payment priority to other debt of the borrower.  The terms governing these debt instruments may include features that can result in principal appreciation under certain circumstances.  The capacity of a company to issue debt securities or other similar debt instruments and the quality of the credit underlying a company’s debt securities or other similar debt instruments are typically determined based upon the projected cash flows of the borrower, the enterprise value of the borrower or both.
 
The Fund is expected to engage in hedging strategies from time to time in an attempt to achieve downside protection and reduce portfolio volatility.  The Fund’s hedging strategies may include, among other things, entering into synthetic credit index short positions, single security short selling, pairs trades, futures contracts, total return and interest rate swaps, and certain options transactions.
 
The Fund is non-diversified and therefore may invest a significant percentage of its assets in the securities of a single issuer.
Risk [Heading] rr_RiskHeading The Fund’s Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock
The Fund’s share price will fluctuate. You could lose money on your investment in the Fund, and the Fund could also return less than other investments. The Fund is subject to the principal risks listed below.

Collateralized Loan Obligations Risk: Typically, collateralized loan obligations are privately offered and sold, and thus are not registered under the securities laws. As a result, the Fund may in certain circumstances characterize its investments in collateralized loan obligation as illiquid. In assessing liquidity, the Fund will consider various factors including whether the collateralized loan obligation may be purchased and sold in Rule 144A transactions and whether an active dealer market exists. collateralized loan obligations are subject to the typical risks associated with debt instruments (i.e., interest rate risk and credit risk). Additional risks of collateralized loan obligations include the possibility that distributions from collateral securities will be insufficient to make interest or other payments, the potential for a decline in the quality of the collateral, and the possibility that the Fund may invest in a subordinate tranche of a collateralized loan obligation.

Convertible Securities Risk: Convertible securities are subject to the risks of both debt securities and equity securities. The values of convertible securities tend to decline as interest rates rise and, due to the conversion feature, tend to vary with fluctuations in the market value of the underlying security.
 
 Counterparty Risk:  A counterparty (the other party to a transaction or an agreement or the party with whom an underlying fund executes transactions) to a transaction with an underlying fund may be unable or unwilling to make timely principal, interest or settlement payments, or otherwise honor its obligations.

Derivatives Risk: The use of derivatives may expose the Fund to additional risks that it would not be subject to if it invested directly in the securities underlying those derivatives. Risks associated with derivatives may include the risk that the derivative does not correlate well with the security, index, or currency to which it relates, the risk that the Fund will be unable to sell or close out the derivative due to an illiquid market, the risk that the counterparty may be unwilling or unable to meet its obligations, and the risk that the derivative could expose the Fund to the risk of magnified losses resulting from leverage. These additional risks could cause the Fund to experience losses to which it would otherwise not be subject.
 
•
Leverage Risk: Leverage occurs when the Fund uses borrowings, derivatives (such as futures or options), or similar instruments or techniques to gain exposure to investments in an amount that exceeds the Fund's initial investment. The use of leverage magnifies changes in the Fund's net asset value and thus may result in increased portfolio volatility and increased risk of loss. Leverage can create an interest expense that may lower the Fund’s overall returns. There can be no guarantee that a leveraging strategy will be successful.
 
•
Futures Contracts Risk: The risks associated with the Fund’s futures positions include liquidity and counterparty risks associated with derivative instruments.

•
Options Risk: Options trading is a highly specialized activity that involves investment techniques and risks different from those associated with ordinary portfolio securities transactions. The value of options can be highly volatile, and their use can result in loss if the Sub-Advisor is incorrect in its expectation of price fluctuations. Options, whether exchange traded or over-the-counter, may also be illiquid.

•
Swap Agreement Risk: Swap agreements (“swaps”) are individually negotiated and structured to include exposure to a variety of different types of investments or market factors. Swaps may increase or decrease the overall volatility of the investments of the Fund and its share price. The performance of swaps may be affected by a change in the specific interest rate, currency, or other factors that determine the amounts of payments due to and from the Fund. A swap can be a form of leverage, which can magnify the Fund’s gains or losses.

Equity Securities Risk: The Fund is subject to the risk that stock prices will fall over short or extended periods of time. Individual companies may report poor results or be negatively affected by industry and/or economic trends and developments. The prices of securities issued by these companies may decline in response to such developments, which could result in a decline in the value of the Fund’s shares.

•
Preferred Stock Risk: In the event an issuer is liquidated or declares bankruptcy, the claims of owners of bonds take precedence over the claims of those who own preferred and common stock. If interest rates rise, the fixed dividend on preferred stocks may be less attractive, causing the price of preferred stocks to decline.

Fixed-Income Risk: The market value of the Fund’s fixed-income securities responds to economic developments, particularly interest rate changes, as well as to perceptions about the creditworthiness of individual issuers, including governments. Generally, the Fund’s fixed-income securities will decrease in value if interest rates rise and increase in value if interest rates fall. Normally, the longer the maturity or duration of the fixed-income securities the Fund owns, the more sensitive the value of the Fund’s shares will be to changes in interest rates.

•
Corporate Loan Risk: The corporate loans, commonly referred to as bank loans, in which the Fund invests may be rated below investment grade. As a result, such corporate loans will be considered speculative with respect to the borrowers’ ability to make payments of interest and principal and will otherwise generally bear risks similar to those associated with non-investment grade securities. There is a high risk that the Fund could suffer a loss from investments in lower rated corporate loans as a result of a default by the borrower.
 
•
Credit Risk: The fixed-income securities in the Fund’s portfolio are subject to the possibility that a deterioration, whether
sudden or gradual, in the financial condition of an issuer, or a deterioration in general economic conditions, could cause an issuer to fail to make timely payments of principal or interest, when due. This may cause the issuer’s securities to decline in value.
 
•
Interest Rate Risk: In general, when interest rates rise, the prices of debt securities fall, and when interest rates fall, the prices of debt securities rise. The price volatility of a debt security also depends on its maturity. Longer-term securities are generally more volatile, so the longer the average maturity or duration of these securities, the greater their price risk.
 
•
Non-Investment-Grade Debt Securities Risk: Non-investment-grade debt securities are sometimes referred to as “junk bonds” and are considered speculative with respect to their issuers’ ability to make payments of interest and principal. There is a high risk that the Fund could suffer a loss from investments in non-investment-grade debt securities caused by the default of an issuer of such securities. Non-investment-grade debt securities may also be less liquid than investment-grade debt securities.

•
Stressed and Distressed Securities Risk: Distressed securities are speculative and involve significant risks in addition to the risks generally applicable to non-investment grade debt securities. Distressed securities bear a substantial risk of default, and may be in default at the time of investment. The Fund will generally not receive interest payments on distressed securities, and there is a significant risk that principal will not be repaid, in full or at all. Distressed securities will likely be illiquid and may be subject to restrictions on resale.

Foreign Securities Risk: Investing in foreign securities poses additional risks since political and economic events unique in a country or region will affect those markets and their issuers, while such events may not necessarily affect the U.S. economy or issuers located in the United States. In addition, investments in foreign securities are generally denominated in foreign currency. As a result, changes in the value of those currencies compared to the U.S. dollar may affect (positively or negatively) the value of the Fund's investments. There are also risks associated with foreign accounting standards, government regulation, market information, and clearance and settlement procedures. Foreign markets may be less liquid and more volatile than U.S. markets and offer less protection to investors.

Fund-of-Funds Risk: Certain Touchstone funds-of-funds may invest in the Fund. As investors purchase and redeem shares of the funds-of-funds, and as the assets of the funds-of-funds are allocated and reallocated among underlying funds, including the Fund, the Fund may experience large inflows or outflows of cash from time to time. As a result, the Fund may be required to sell securities or invest cash at times when it otherwise would not do so, realize additional capital gains or incur increased transaction costs, all of which could adversely affect the Fund’s performance. This activity could also have adverse effects on the Fund’s expense ratio, which will generally fall as the Fund’s assets increase and rise as the Fund’s assets decrease.
 
Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell. This can reduce the Fund’s returns because the Fund may be unable to transact at advantageous times or prices, or at all.
 
Management Risk: In managing the Fund’s portfolio, the Advisor engages one or more sub-advisors to make investment decisions for a portion of or the entire portfolio. There is a risk that the Advisor may be unable to identify and retain sub-advisors who achieve superior investment returns relative to other similar sub-advisors.

Non-Diversification Risk: The Fund is non-diversified, which means that it may invest a greater percentage of its assets than a diversified mutual fund in the securities of a limited number of issuers. The use of a non-diversified investment strategy may increase the volatility of the Fund’s investment performance, as the Fund may be more susceptible to risks associated with a single economic, political or regulatory event.

Pay-In-Kind Bonds Risk: Pay-in-kind bonds, a type of mezzanine financing, are securities that, at the issuer’s option, pay interest in either cash or additional securities for a specified period. Pay-in-kind bonds, like zero coupon bonds, are designed to give an issuer flexibility in managing cash flow. Pay-in-kind bonds are expected to reflect the market value of the underlying debt plus an amount representing accrued interest since the last payment. Pay-in-kind bonds are usually less volatile than zero coupon bonds, but more volatile than cash pay securities.
 
Rule 144A Securities Risk: Rule 144A securities are restricted securities that may be purchased only by qualified institutional buyers in reliance on an exemption from federal registration requirements. Investing in Rule 144A securities may reduce the liquidity of the Fund's portfolio if an adequate institutional trading market for these securities does not exist. Prices of Rule 144A securities often reflect a discount, which may be significant, from the market price of comparable exchange-listed securities for which a liquid trading market exists. 
 
Short Sales Risk: In a short sale, the Fund sells a security or other financial instrument, such as a futures contract, that it does not own. To complete the transaction, the Fund must borrow the security to make delivery to the buyer. The Fund is then obligated to replace the borrowed security by purchasing the security at the market price at the time of replacement. If the price of the security sold short rises between the time the Fund sells the security short and the time the Fund replaces the security sold short, the Fund will realize a loss on the transaction.  
 
As with any mutual fund, there is no guarantee that the Fund will achieve its investment goal. You can find more information about the Fund’s investments and risks under the “Principal Investment Strategies and Risks” section of the Fund’s prospectus.
Risk Lose Money [Text] rr_RiskLoseMoney The Fund’s share price will fluctuate. You could lose money on your investment in the Fund, and the Fund could also return less than other investments. The Fund is subject to the principal risks listed below.
Risk Nondiversified Status [Text] rr_RiskNondiversifiedStatus Non-Diversification Risk: The Fund is non-diversified, which means that it may invest a greater percentage of its assets than a diversified mutual fund in the securities of a limited number of issuers. The use of a non-diversified investment strategy may increase the volatility of the Fund’s investment performance, as the Fund may be more susceptible to risks associated with a single economic, political or regulatory event.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading The Fund’s Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
The bar chart and performance table below illustrate some indication of the risks and volatility of an investment in the Fund by showing the Fund's performance for its first full year of operations and by showing how the Fund's average annual total returns for one year and since inception compare with the BofA Merrill Lynch 3-Month U.S. Treasury Bill Index. The bar chart does not reflect any sales charges, which would reduce your return. The performance table does reflect any applicable sales charges. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. More recent performance information is available at no cost by visiting TouchstoneInvestments.com or by calling 1.800.543.0407.
Performance One Year or Less [Text] rr_PerformanceOneYearOrLess The bar chart and performance table below illustrate some indication of the risks and volatility of an investment in the Fund by showing the Fund's performance for its first full year of operations and by showing how the Fund's average annual total returns for one year and since inception compare with the BofA Merrill Lynch 3-Month U.S. Treasury Bill Index.
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone 1.800.543.0407
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress TouchstoneInvestments.com
Bar Chart [Heading] rr_BarChartHeading Touchstone Credit Opportunities Fund— Class A Shares Total Return as of
Bar Chart Footnotes [Text Block] rr_BarChartFootnotesTextBlock
Best Quarter: Third Quarter 2016 3.83%
 
Worst Quarter: Fourth Quarter 2016 1.87%

The return of the Fund's Class A shares for the nine months ended September 30, 2017 was 5.67%.
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter:
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2016
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 3.83%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter:
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2016
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn 1.87%
Performance Table Heading rr_PerformanceTableHeading Average Annual Total Returns for the periods ended December 31, 2015*
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes reflects no deductions for fees, expenses or taxes
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Your after-tax returns may differ from those shown and depend on your tax situation. The after-tax returns do not apply to shares held in an IRA, 401(k), or other tax-advantaged account.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown After-tax returns are only shown for Class A shares and after-tax returns for other classes will vary.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock
After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Your after-tax returns may differ from those shown and depend on your tax situation. The after-tax returns do not apply to shares held in an IRA, 401(k), or other tax-advantaged account. After-tax returns are only shown for Class A shares and after-tax returns for other classes will vary.
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2015
TOUCHSTONE STRATEGIC TRUST | Touchstone Credit Opportunities Fund | Touchstone Credit Opportunities Fund, Class A  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TCOAX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 1.10%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Component1 Other Expenses rr_Component1OtherExpensesOverAssets 0.18%
Component2 Other Expenses rr_Component2OtherExpensesOverAssets 14.48%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 14.66%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 16.02%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (14.14%)
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.88%
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2018
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 755
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 3,535
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 5,737
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 9,437
Annual Return 2016 rr_AnnualReturn2016 11.44%
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2017
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 5.67%
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 5.06%
Since Inception rr_AverageAnnualReturnSinceInception 1.97%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2015
TOUCHSTONE STRATEGIC TRUST | Touchstone Credit Opportunities Fund | Touchstone Credit Opportunities Fund, Class A | After Taxes on Distributions  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Federal Income Taxes on Distributions
1 Year rr_AverageAnnualReturnYear01 2.88%
Since Inception rr_AverageAnnualReturnSinceInception 0.18%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2015
TOUCHSTONE STRATEGIC TRUST | Touchstone Credit Opportunities Fund | Touchstone Credit Opportunities Fund, Class A | After Taxes on Distributions and Sales  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Federal Income Taxes on Distributions and Sale of Fund Shares
1 Year rr_AverageAnnualReturnYear01 2.82%
Since Inception rr_AverageAnnualReturnSinceInception 0.67%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2015
TOUCHSTONE STRATEGIC TRUST | Touchstone Credit Opportunities Fund | Touchstone Credit Opportunities Fund, Class C  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TOCCX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 1.10%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Component1 Other Expenses rr_Component1OtherExpensesOverAssets 0.18%
Component2 Other Expenses rr_Component2OtherExpensesOverAssets 71.02%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 71.20%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 73.31%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (70.68%)
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 2.63%
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 366
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 6,774
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 7,427
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 7,500
Expense Example, No Redemption, 1 Year rr_ExpenseExampleNoRedemptionYear01 266
Expense Example, No Redemption, 3 Years rr_ExpenseExampleNoRedemptionYear03 6,774
Expense Example, No Redemption, 5 Years rr_ExpenseExampleNoRedemptionYear05 7,427
Expense Example, No Redemption, 10 Years rr_ExpenseExampleNoRedemptionYear10 $ 7,500
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 9.67%
Since Inception rr_AverageAnnualReturnSinceInception 6.03%
TOUCHSTONE STRATEGIC TRUST | Touchstone Credit Opportunities Fund | Touchstone Credit Opportunities Fund, Class Y  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TCOYX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 1.10%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Component1 Other Expenses rr_Component1OtherExpensesOverAssets 0.18%
Component2 Other Expenses rr_Component2OtherExpensesOverAssets 6.97%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 7.15%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 8.26%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (6.63%)
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.63%
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 166
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 1,818
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 3,365
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 6,811
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 11.63%
Since Inception rr_AverageAnnualReturnSinceInception 6.78%
TOUCHSTONE STRATEGIC TRUST | Touchstone Credit Opportunities Fund | Touchstone Credit Opportunities Fund, Institutional  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TOCIX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 1.10%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Component1 Other Expenses rr_Component1OtherExpensesOverAssets 0.18%
Component2 Other Expenses rr_Component2OtherExpensesOverAssets 0.41%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.59%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 1.70%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.17%)
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.53%
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 156
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 519
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 907
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 1,994
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 11.73%
Since Inception rr_AverageAnnualReturnSinceInception 6.88%
TOUCHSTONE STRATEGIC TRUST | Touchstone Credit Opportunities Fund | Touchstone Credit Opportunities Fund, Institutional | BofA Merrill Lynch Three-Month U.S. Treasury Bill Index  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel BofA Merrill Lynch 3-Month U.S. Treasury Bill Index (reflects no deductions for fees, expenses or taxes)
1 Year rr_AverageAnnualReturnYear01 0.33%
Since Inception rr_AverageAnnualReturnSinceInception 0.27%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2015
TOUCHSTONE STRATEGIC TRUST | Touchstone Global Growth Fund  
Prospectus: rr_ProspectusTable  
Risk/Return [Heading] rr_RiskReturnHeading TOUCHSTONE GLOBAL GROWTH FUND SUMMARY
Objective [Heading] rr_ObjectiveHeading The Fund’s Investment Goal
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock
The Touchstone Global Growth Fund (the “Fund”) seeks to achieve long-term capital appreciation.
Expense [Heading] rr_ExpenseHeading The Fund’s Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock
This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts for Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 or more in the Touchstone Funds. More information about these and other discounts is available from your financial professional, in the section entitled “Choosing a Class of Shares” in the Fund’s prospectus and Statement of Additional Information ("SAI") on page 60 and 77, respectively, and, in Appendix A — Intermediary-Specific Sales Charge Waivers and Discounts to the Fund's prospectus.
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder Fees (fees paid directly from your investment)
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)
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading Portfolio Turnover.
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock
The Fund pays transaction costs, such as brokerage 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 the most recent fiscal year, the Fund's portfolio turnover rate was 72% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 72.00%
Expense Breakpoint Discounts [Text] rr_ExpenseBreakpointDiscounts You may qualify for sales charge discounts for Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 or more in the Touchstone Funds.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount $ 50,000
Expense Example [Heading] rr_ExpenseExampleHeading 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
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption The example assumes that you invest $10,000 in the Fund for the time periods indicated and then, except as indicated, redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, that the Fund’s operating expenses remain the same and that all fee waivers or expense limits for the Fund will expire after one year.  Although your actual costs may be higher or lower, based on these assumptions your costs would be:Assuming Redemption at End of Period
Expense Example, No Redemption, By Year, Caption [Text] rr_ExpenseExampleNoRedemptionByYearCaption Assuming No Redemption
Strategy [Heading] rr_StrategyHeading The Fund’s Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock
Under normal circumstances, the Fund will generally invest its net assets (plus any borrowings for investment purposes) in equity securities of large capitalization issuers. Equity securities include, but are not limited to, common stocks, preferred stocks, securities convertible into common stocks, rights and warrants. The Fund generally will contain 30 to 50 equity securities. The Fund currently defines a “large capitalization issuer” as one that has a market capitalization of $10 billion or more at the time of purchase.

Under normal market conditions, at least 40% of the Fund’s net assets will be invested in the securities of foreign issuers, including those in emerging markets, through, but not limited to, American Depository Receipts ("ADRs") or other depositary receipts. The Fund intends to invest in securities of issuers from at least three different countries outside of the United States, including in emerging markets. The Fund is a non-diversified fund and may, from time to time, have significant exposure to one or more issuers, industries, geographic regions or sectors.

DSM Capital Partners LLC ("DSM"), the Fund's sub-advisor, manages the Fund using a bottom-up, “idea-driven,” growth-style with a long-term (i.e., three-year) investment horizon. This means in general terms that DSM seeks to identify issuers which it believes exhibit certain quality characteristics. DSM generally sells an equity security when its projected future return becomes unattractive relative to the rest of the portfolio or the investable universe.
Risk [Heading] rr_RiskHeading The Fund’s Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock
Convertible Securities Risk: Convertible securities are subject to the risks of both debt securities and equity securities. The values of convertible securities tend to decline as interest rates rise and, due to the conversion feature, tend to vary with fluctuations in the market value of the underlying security.
 
Equity Securities Risk: The Fund is subject to the risk that stock prices will fall over short or extended periods of time. Individual companies may report poor results or be negatively affected by industry and/or economic trends and developments. The prices of securities issued by these companies may decline in response to such developments, which could result in a decline in the value of the Fund’s shares.

•
Large-Cap Risk: Large-cap companies may be unable to respond quickly to new competitive challenges, such as changes in technology and consumer tastes, and also may not be able to attain the high growth rate of successful smaller companies, especially during extended periods of economic expansion.

•
Preferred Stock Risk: In the event an issuer is liquidated or declares bankruptcy, the claims of owners of bonds take precedence over the claims of those who own preferred and common stock. If interest rates rise, the fixed dividend on preferred stocks may be less attractive, causing the price of preferred stocks to decline.

Foreign Securities Risk: Investing in foreign securities poses additional risks since political and economic events unique in a country or region will affect those markets and their issuers, while such events may not necessarily affect the U.S. economy or issuers located in the United States. In addition, investments in foreign securities are generally denominated in foreign currency. As a result, changes in the value of those currencies compared to the U.S. dollar may affect (positively or negatively) the value of the Fund's investments. There are also risks associated with foreign accounting standards, government regulation, market information, and clearance and settlement procedures. Foreign markets may be less liquid and more volatile than U.S. markets and offer less protection to investors.

•
Depositary Receipts Risk: Foreign receipts, which include ADRs, Global Depositary Receipts, and European Depositary Receipts, are securities that evidence ownership interests in a security or a pool of securities issued by a foreign issuer. The risks of depositary receipts include many risks associated with investing directly in foreign securities.

•
Emerging Markets Risk: Emerging markets may be more likely to experience political turmoil or rapid changes in market or economic conditions than more developed countries. In addition, the financial stability of issuers (including governments) in emerging market countries may be more precarious than that of issuers in other countries.

Growth-Investing Risk:  Growth-oriented funds may underperform when value investing is in favor, and growth stocks may be more volatile than other stocks because they are more sensitive to investor perceptions of the issuing company’s growth of earnings potential.

Management Risk: In managing the Fund’s portfolio, the Advisor engages one or more sub-advisors to make investment decisions for a portion of or the entire portfolio. There is a risk that the Advisor may be unable to identify and retain sub-advisors who achieve superior investment returns relative to other similar sub-advisors. 
 
Non-Diversification Risk: The Fund is non-diversified, which means that it may invest a greater percentage of its assets than a diversified mutual fund in the securities of a limited number of issuers. The use of a non-diversified investment strategy may increase the volatility of the Fund’s investment performance, as the Fund may be more susceptible to risks associated with a single economic, political or regulatory event.

Sector Focus Risk: A fund that focuses its investments in the securities of a particular market sector is subject to the risk that adverse circumstances will have a greater impact on the fund than a fund that does not focus its investments in a particular sector.

As with any mutual fund, there is no guarantee that the Fund will achieve its investment goal. You can find more information about the Fund’s investments and risks under the “Principal Investment Strategies and Risks” section of the Fund’s prospectus.
Risk Lose Money [Text] rr_RiskLoseMoney The Fund’s share price will fluctuate. You could lose money on your investment in the Fund, and the Fund could also return less than other investments. The Fund is subject to the principal risks listed below.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading The Fund’s Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
The bar chart and the performance table below illustrate some indication of the risks and volatility of an investment in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and by showing how the Fund’s average annual total returns for one year and since inception compare with the MSCI All Country World Index, Net. The performance table does reflect any applicable sales charges. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. More recent performance information is available at no cost by visiting TouchstoneInvestments.com or by calling 1.800.543.0407.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The bar chart and the performance table below illustrate some indication of the risks and volatility of an investment in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and by showing how the Fund’s average annual total returns for one year and since inception compare with the MSCI All Country World Index, Net
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone 1.800.543.0407
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress TouchstoneInvestments.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading Touchstone Global Growth Fund— Institutional Class Shares Total Return as of December 31
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock
Best Quarter: Fourth Quarter 2013 14.27%
 
Worst Quarter: Third Quarter 2015 (7.75)%


The return of the Fund's Institutional Class shares for the nine months ended September 30, 2017 was 36.57%.
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter:
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Dec. 31, 2013
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 14.27%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter:
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Sep. 30, 2015
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (7.75%)
Performance Table Heading rr_PerformanceTableHeading Average Annual Total Returns for the periods ended December 31, 2015*
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes (reflects no deductions for fees, expenses or taxes)
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Your after-tax returns may differ from those shown and depend on your tax situation. The after-tax returns do not apply to shares held in an IRA, 401(k), or other tax-advantaged account.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown After-tax returns are only shown for Institutional Class shares and after-tax returns for other classes will vary.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock
Before the Fund commenced operations, all of the assets and liabilities of the DSM Global Growth Fund (the “Predecessor Fund”) were transferred to the Fund in a tax-free reorganization (the “Reorganization”). The Reorganization occurred on August 15, 2016. As a result of the Reorganization, the Fund assumed the performance and accounting history of the Predecessor Fund. For more information on the prior history of the Fund, please see the section entitled “The Trust” in the Fund’s Statement of Additional Information.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Your after-tax returns may differ from those shown and depend on your tax situation. The after-tax returns do not apply to shares held in an IRA, 401(k), or other tax-advantaged account. After-tax returns are only shown for Institutional Class shares and after-tax returns for other classes will vary.

The inception dates of Class A shares, Class C shares, Class Y shares, and Institutional Class shares were August 15, 2016, August 15, 2016, August 15, 2016 and March 28, 2012, respectively. The performance of each share class was calculated using the historical performance of Institutional Class shares for periods prior to August 15, 2016. Performance for these periods has been restated to reflect the impact of the fees and expenses applicable to Class A, Class C and Class Y shares. 
TOUCHSTONE STRATEGIC TRUST | Touchstone Global Growth Fund | MSCI All Country World Index Net  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel MSCI All Country World Index, Net (reflects no deductions for fees, expenses or taxes)
1 Year rr_AverageAnnualReturnYear01 7.86%
Since Inception rr_AverageAnnualReturnSinceInception 7.28%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 15, 2016
TOUCHSTONE STRATEGIC TRUST | Touchstone Global Growth Fund | Touchstone Global Growth Fund, Class A  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TGGAX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.90%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 41.78%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 42.93%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (41.52%) [1]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.41% [1]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2018
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 710
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 6,215
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 8,336
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 9,542
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (8.08%)
Since Inception rr_AverageAnnualReturnSinceInception 8.67%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 15, 2016
TOUCHSTONE STRATEGIC TRUST | Touchstone Global Growth Fund | Touchstone Global Growth Fund, Class C  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TGGCX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.90%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 235.56%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 237.46%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (235.30%) [1]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 2.16% [1]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 319
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 12,429
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 12,429
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 12,429
Expense Example, No Redemption, 1 Year rr_ExpenseExampleNoRedemptionYear01 219
Expense Example, No Redemption, 3 Years rr_ExpenseExampleNoRedemptionYear03 12,429
Expense Example, No Redemption, 5 Years rr_ExpenseExampleNoRedemptionYear05 12,429
Expense Example, No Redemption, 10 Years rr_ExpenseExampleNoRedemptionYear10 $ 12,429
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (4.14%)
Since Inception rr_AverageAnnualReturnSinceInception 7.86%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 15, 2016
TOUCHSTONE STRATEGIC TRUST | Touchstone Global Growth Fund | Touchstone Global Growth Fund, Class Y  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TYGGX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.90%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 50.78%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 51.68%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (50.52%) [1]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.16% [1]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 118
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 6,426
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 8,219
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 8,901
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (2.28%)
Since Inception rr_AverageAnnualReturnSinceInception 8.90%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 15, 2016
TOUCHSTONE STRATEGIC TRUST | Touchstone Global Growth Fund | Touchstone Global Growth Fund, Institutional Class  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol DSMGX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.90%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.92%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 1.82%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.76%) [1]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.06% [1]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 108
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 499
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 914
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 2,075
Annual Return 2013 rr_AnnualReturn2013 34.42%
Annual Return 2014 rr_AnnualReturn2014 3.26%
Annual Return 2015 rr_AnnualReturn2015 8.07%
Annual Return 2016 rr_AnnualReturn2016 (2.22%)
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 36.57%
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (2.22%)
Since Inception rr_AverageAnnualReturnSinceInception 8.91%
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 28, 2012
TOUCHSTONE STRATEGIC TRUST | Touchstone Global Growth Fund | Touchstone Global Growth Fund, Institutional Class | After Taxes on Distributions  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Federal Income Taxes on Distributions
1 Year rr_AverageAnnualReturnYear01 (2.79%)
Since Inception rr_AverageAnnualReturnSinceInception 7.51%
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 28, 2012
TOUCHSTONE STRATEGIC TRUST | Touchstone Global Growth Fund | Touchstone Global Growth Fund, Institutional Class | After Taxes on Distributions and Sales  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Federal Income Taxes on Distributions and Sale of Fund Shares
1 Year rr_AverageAnnualReturnYear01 (0.84%)
Since Inception rr_AverageAnnualReturnSinceInception 6.84%
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 28, 2012
TOUCHSTONE STRATEGIC TRUST | Touchstone International Small Cap Fund  
Prospectus: rr_ProspectusTable  
Risk/Return [Heading] rr_RiskReturnHeading TOUCHSTONE INTERNATIONAL SMALL CAP FUND SUMMARY
Objective [Heading] rr_ObjectiveHeading The Fund’s Investment Goal
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock
The Touchstone International Small Cap Fund (the “Fund”) seeks to provide investors with capital appreciation.
Expense [Heading] rr_ExpenseHeading The Fund’s Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock
This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts for Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 or more in the Touchstone Funds. More information about these and other discounts is available from your financial professional, in the section entitled “Choosing a Class of Shares” in the Fund’s prospectus and Statement of Additional Information ("SAI") on page 60 and 77, respectively, and, in Appendix A — Intermediary-Specific Sales Charge Waivers and Discounts to the Fund's prospectus.
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder Fees (fees paid directly from your investment)
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)
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading Portfolio Turnover.
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock
The Fund pays transaction costs, such as brokerage 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 the most recent fiscal year, the Fund's portfolio turnover rate was 89% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 89.00%
Expense Breakpoint Discounts [Text] rr_ExpenseBreakpointDiscounts You may qualify for sales charge discounts for Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 or more in the Touchstone Funds.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount $ 50,000
Expense Example [Heading] rr_ExpenseExampleHeading 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 example assumes that you invest $10,000 in the Fund for the time periods indicated and then, except as indicated, redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, that the Fund’s operating expenses remain the same and that all fee waivers or expense limits for the Fund will expire after one year. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption Assuming Redemption at End of Period
Expense Example, No Redemption, By Year, Caption [Text] rr_ExpenseExampleNoRedemptionByYearCaption Assuming No Redemption
Strategy [Heading] rr_StrategyHeading The Fund’s Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock
The Fund normally invests at least 80% of its assets in equity securities of non-U.S. small-cap companies, including companies located in emerging market countries. For purposes of this Fund, small-cap companies are those companies with market capitalizations at the time of investment similar to the market capitalizations of companies in the S&P Developed ex-U.S. SmallCap Index (between approximately $8 million and $15.6 billion as of September 30, 2017). The size of the companies in the S&P Developed ex-U.S. SmallCap Index will change with market conditions. For purposes of this Fund, non-U.S. companies are companies that meet at least one of the following criteria:
 
•
They are organized under the laws of a foreign country.
•
They maintain their principal place of business in a foreign country.
•
The principal trading market for their securities is located in a foreign country.
•
They derive at least 50% of their revenues or profits from operations in foreign countries.
•
They have at least 50% of their assets located in foreign countries.
 
Equity securities include common and preferred stocks and American Depositary Receipts (“ADRs”) and other depositary receipts.
 
When identifying potential investments, the Fund's sub-advisor, Copper Rock Capital Partners LLC ("Copper Rock"), looks for companies it believes have strong management, superior earnings growth prospects, and attractive relative valuations. Copper Rock typically sells or reduces a position when the target price for a stock is attained, there is a change in the company’s management team or business objectives, or when there is deterioration in a company’s fundamentals.
Risk [Heading] rr_RiskHeading The Fund’s Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock
The Fund’s share price will fluctuate. You could lose money on your investment in the Fund, and the Fund could also return less than other investments. The Fund is subject to the principal risks listed below.

Equity Securities Risk: The Fund is subject to the risk that stock prices will fall over short or extended periods of time. Individual companies may report poor results or be negatively affected by industry and/or economic trends and developments. The prices of securities issued by these companies may decline in response to such developments, which could result in a decline in the value of the Fund’s shares.
 
•
Preferred Stock Risk: In the event an issuer is liquidated or declares bankruptcy, the claims of owners of bonds take precedence over the claims of those who own preferred and common stock. If interest rates rise, the fixed dividend on preferred stocks may be less attractive, causing the price of preferred stocks to decline.
 
•
Small-Cap Risk:  Stocks of smaller companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies. Small companies may have limited product lines or financial resources and may be dependent upon a small or inexperienced management group.

Foreign Securities Risk: Investing in foreign securities poses additional risks since political and economic events unique in a country or region will affect those markets and their issuers, while such events may not necessarily affect the U.S. economy or issuers located in the United States. In addition, investments in foreign securities are generally denominated in foreign currency. As a result, changes in the value of those currencies compared to the U.S. dollar may affect (positively or negatively) the value of the Fund's investments. There are also risks associated with foreign accounting standards, government regulation, market information, and clearance and settlement procedures. Foreign markets may be less liquid and more volatile than U.S. markets and offer less protection to investors.

•
Depositary Receipts Risk: Foreign receipts, which include ADRs, Global Depositary Receipts, and European Depositary Receipts, are securities that evidence ownership interests in a security or a pool of securities issued by a foreign issuer. The risks of depositary receipts include many risks associated with investing directly in foreign securities.

•
Emerging Markets Risk: Emerging markets may be more likely to experience political turmoil or rapid changes in market or economic conditions than more developed countries. In addition, the financial stability of issuers (including governments) in emerging market countries may be more precarious than that of issuers in other countries.
 
Management Risk: In managing the Fund’s portfolio, the Advisor engages one or more sub-advisors to make investment decisions for a portion of or the entire portfolio. There is a risk that the Advisor may be unable to identify and retain sub-advisors who achieve superior investment returns relative to other similar sub-advisors.
 
As with any mutual fund, there is no guarantee that the Fund will achieve its investment goal. You can find more information about the Fund’s investments and risks under the “Principal Investment Strategies and Risks” section of the Fund’s prospectus.
Risk Lose Money [Text] rr_RiskLoseMoney The Fund’s share price will fluctuate. You could lose money on your investment in the Fund, and the Fund could also return less than other investments. The Fund is subject to the principal risks listed below.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading The Fund’s Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
The bar chart and performance table below illustrate some indication of the risks and volatility of an investment in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and by showing how the Fund’s average annual total returns for one year, five years, and ten years compare with the S&P Developed ex-U.S. SmallCap Index. The bar chart does not reflect any sales charges, which would reduce your return. The performance table does reflect any applicable sales charges. Effective May 23, 2011, the Fund’s investment strategy changed from a domestic small-cap strategy to an international small-cap strategy. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. More recent performance information is available at no cost by visiting TouchstoneInvestments.com or by calling 1.800.543.0407.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The bar chart and performance table below illustrate some indication of the risks and volatility of an investment in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and by showing how the Fund’s average annual total returns for one year, five years, and ten years compare with the S&P Developed ex-U.S. SmallCap Index.
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone 1.800.543.0407
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress TouchstoneInvestments.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading Touchstone International Small Cap Fund — Class A Shares Total Return as of December 31
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads The bar chart does not reflect any sales charges, which would reduce your return.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock
Best Quarter: Fourth Quarter 2010 18.03%
 
Worst Quarter: Fourth Quarter 2008 (22.48)%
 
The return of the Fund’s Class A shares for the nine months ended September 30, 2017 was 24.74%
Performance Table Heading rr_PerformanceTableHeading Average Annual Total Returns for the periods ended December 31, 2015*
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes reflects no deduction for fees, expenses or taxes
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Your after-tax returns may differ from those shown and depend on your tax situation. The after-tax returns do not apply to shares held in an IRA, 401(k), or other tax-advantaged account.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown After-tax returns are only shown for Class A shares and after-tax returns for other classes will vary.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock
Before the Fund commenced operations, all of the assets and liabilities of the Old Mutual International Small Cap Fund (the “Predecessor Fund”) were transferred to the Fund in a tax-free reorganization (the “Reorganization”). The Reorganization occurred on April 12, 2012. As a result of the Reorganization, the Fund assumed the performance and accounting history of the Predecessor Fund prior to the date of the Reorganization. For more information on the prior history of the Fund, please see the section entitled “The Trust” in the Fund’s SAI.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Your after-tax returns may differ from those shown and depend on your tax situation. The after-tax returns do not apply to shares held in an IRA, 401(k), or other tax-advantaged account. After-tax returns are only shown for Class A shares and after-tax returns for other classes will vary.

The inception dates of Class A shares, Class C shares, Class Y shares, and Institutional Class shares were July 31, 2003, April 12, 2012, December 31, 1996 and December 20, 2006, respectively. Class C and Institutional Class shares’ performance was calculated using the historical performance of Class Y shares for the periods prior to April 12, 2012 and December 20, 2006, respectively. Performance for these periods has been restated to reflect the impact of the fees and expenses applicable to Class C and Institutional Class shares.
TOUCHSTONE STRATEGIC TRUST | Touchstone International Small Cap Fund | S&P Developed ex-U.S. SmallCap Index  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel S&P Developed ex-U.S. SmallCap Index (reflects no deduction for fees, expenses or taxes)
1 Year rr_AverageAnnualReturnYear01 3.78%
5 Years rr_AverageAnnualReturnYear05 9.67%
10 Years rr_AverageAnnualReturnYear10 3.03%
TOUCHSTONE STRATEGIC TRUST | Touchstone International Small Cap Fund | Touchstone International Small Cap Fund, Class A  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TNSAX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.94%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.52%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 1.72% [2]
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.16%) [3]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.56% [3]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2018
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 725
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 1,071
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 1,441
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 2,476
Annual Return 2007 rr_AnnualReturn2007 11.96%
Annual Return 2008 rr_AnnualReturn2008 (40.72%)
Annual Return 2009 rr_AnnualReturn2009 26.65%
Annual Return 2010 rr_AnnualReturn2010 23.15%
Annual Return 2011 rr_AnnualReturn2011 (7.49%)
Annual Return 2012 rr_AnnualReturn2012 21.29%
Annual Return 2013 rr_AnnualReturn2013 28.08%
Annual Return 2014 rr_AnnualReturn2014 (0.07%)
Annual Return 2015 rr_AnnualReturn2015 9.76%
Annual Return 2016 rr_AnnualReturn2016 (8.69%)
Year to Date Return, Label rr_YearToDateReturnLabel The return of the Fund’s Class A sharesThe return of the Fund’s Class A shares
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2017
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 24.74%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter:
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Dec. 31, 2010
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 18.03%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter:
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (22.48%)
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (13.92%)
5 Years rr_AverageAnnualReturnYear05 7.96%
10 Years rr_AverageAnnualReturnYear10 3.46%
Inception Date rr_AverageAnnualReturnInceptionDate Jul. 31, 2003
TOUCHSTONE STRATEGIC TRUST | Touchstone International Small Cap Fund | Touchstone International Small Cap Fund, Class A | After Taxes on Distributions  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Taxes on Distributions
1 Year rr_AverageAnnualReturnYear01 (14.00%)
5 Years rr_AverageAnnualReturnYear05 7.81%
10 Years rr_AverageAnnualReturnYear10 2.75%
Inception Date rr_AverageAnnualReturnInceptionDate Jul. 31, 2003
TOUCHSTONE STRATEGIC TRUST | Touchstone International Small Cap Fund | Touchstone International Small Cap Fund, Class A | After Taxes on Distributions and Sales  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Taxes on Distributions and Sale of Fund Shares
1 Year rr_AverageAnnualReturnYear01 (7.60%)
5 Years rr_AverageAnnualReturnYear05 6.40%
10 Years rr_AverageAnnualReturnYear10 2.56%
Inception Date rr_AverageAnnualReturnInceptionDate Jul. 31, 2003
TOUCHSTONE STRATEGIC TRUST | Touchstone International Small Cap Fund | Touchstone International Small Cap Fund, Class C  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TNSCX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.94%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.79%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 2.74% [2]
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.43%) [3]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 2.31% [3]
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 334
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 810
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 1,411
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 3,039
Expense Example, No Redemption, 1 Year rr_ExpenseExampleNoRedemptionYear01 234
Expense Example, No Redemption, 3 Years rr_ExpenseExampleNoRedemptionYear03 810
Expense Example, No Redemption, 5 Years rr_ExpenseExampleNoRedemptionYear05 1,411
Expense Example, No Redemption, 10 Years rr_ExpenseExampleNoRedemptionYear10 $ 3,039
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (10.34%)
5 Years rr_AverageAnnualReturnYear05 8.67%
10 Years rr_AverageAnnualReturnYear10 3.39%
Inception Date rr_AverageAnnualReturnInceptionDate Apr. 12, 2012
TOUCHSTONE STRATEGIC TRUST | Touchstone International Small Cap Fund | Touchstone International Small Cap Fund, Institutional  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TNSIX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.94%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.29%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 1.24% [2]
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.05%) [3]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.19% [3]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 121
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 388
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 676
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 1,496
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (8.37%)
5 Years rr_AverageAnnualReturnYear05 9.72%
10 Years rr_AverageAnnualReturnYear10 4.51%
Inception Date rr_AverageAnnualReturnInceptionDate Dec. 20, 2006
TOUCHSTONE STRATEGIC TRUST | Touchstone International Small Cap Fund | Touchstone International Small Cap Fund, Class Y  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TNSYX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.94%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.38%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 1.33% [2]
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.02%) [3]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.31% [3]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 133
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 419
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 727
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 1,600
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (8.51%)
5 Years rr_AverageAnnualReturnYear05 9.53%
10 Years rr_AverageAnnualReturnYear10 4.32%
Inception Date rr_AverageAnnualReturnInceptionDate Dec. 31, 1996
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Cap Fund  
Prospectus: rr_ProspectusTable  
Risk/Return [Heading] rr_RiskReturnHeading TOUCHSTONE LARGE CAP FUND SUMMARY
Objective [Heading] rr_ObjectiveHeading The Fund’s Investment Goal
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock
The Touchstone Large Cap Fund (the “Fund”) seeks to provide investors with long-term capital growth.
Expense [Heading] rr_ExpenseHeading The Fund’s Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock
This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts for Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 or more in the Touchstone Funds. More information about these and other discounts is available from your financial professional, in the section entitled “Choosing a Class of Shares” in the Fund’s prospectus and Statement of Additional Information ("SAI") on page 60 and 77, respectively, and, in Appendix A — Intermediary-Specific Sales Charge Waivers and Discounts to the Fund's prospectus.
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder Fees (fees paid directly from your investment)
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)
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading Portfolio Turnover.
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock
The Fund pays transaction costs, such as brokerage commissions, when it buys and sells securities (i.e., “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 total annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 23% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 23.00%
Expense Breakpoint Discounts [Text] rr_ExpenseBreakpointDiscounts You may qualify for sales charge discounts for Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 or more in the Touchstone Funds.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount $ 50,000
Expense Example [Heading] rr_ExpenseExampleHeading 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 example assumes that you invest $10,000 in the Fund for the time periods indicated and then, except as indicated, redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, that the Fund’s operating expenses remain the same and that all fee waivers or expense limits for the Fund will expire after one year. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption Assuming Redemption at End of Period
Expense Example, No Redemption, By Year, Caption [Text] rr_ExpenseExampleNoRedemptionByYearCaption Assuming No Redemption
Strategy [Heading] rr_StrategyHeading The Fund’s Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock
The Fund invests, under normal market conditions, at least 80% of its assets in common stocks of large capitalization U.S. listed companies. For purposes of the Fund, a large capitalization company has a market capitalization within the range represented in the Russell 1000® Index (between $1 billion and $807 billion as of September 30, 2017) at the time of purchase. The size of the companies in the Russell 1000® Index will change with market conditions.
 
The Fund’s sub-advisor, London Company of Virginia d/b/a/ The London Company (the “The London Company”), seeks to purchase financially stable large-cap companies that it believes are consistently generating high returns on unleveraged operating capital, run by shareholder-oriented management, and trading at a discount to the company’s respective private market values. Guiding principles of the The London Company’s large-cap philosophy include: (1) a focus on cash return on tangible capital, not earnings per share; (2) balance sheet optimization; (3) optimal allocation of investments is essential to good investment results; and (4) low turnover and tax sensitivity enhances real returns.
 
The Fund is non-diversified and will typically hold approximately 30 to 40 securities. The London Company invests for the long term and attempts to minimize turnover in an effort to reduce transaction costs and taxes.The London Company generally sells a security when: it becomes overvalued and has reached its price target; the issuer’s fundamentals deteriorate; there is significant trading activity by insiders; or there is a more promising alternative. The London Company may also sell a security to adjust the Fund’s overall portfolio risk.
Risk [Heading] rr_RiskHeading The Fund’s Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock
The Fund’s share price will fluctuate. You could lose money on your investment in the Fund, and the Fund could also return less than other investments. The Fund is subject to the principal risks listed below.

Equity Securities Risk: The Fund is subject to the risk that stock prices will fall over short or extended periods of time. Individual companies may report poor results or be negatively affected by industry and/or economic trends and developments. The prices of securities issued by these companies may decline in response to such developments, which could result in a decline in the value of the Fund’s shares.

•
Large-Cap Risk: Large-cap companies may be unable to respond quickly to new competitive challenges, such as changes in technology and consumer tastes, and also may not be able to attain the high growth rate of successful smaller companies, especially during extended periods of economic expansion.
 
Management Risk: In managing the Fund’s portfolio, the Advisor engages one or more sub-advisors to make investment decisions for a portion of or the entire portfolio. There is a risk that the Advisor may be unable to identify and retain sub-advisors who achieve superior investment returns relative to other similar sub-advisors.

Non-Diversification Risk: The Fund is non-diversified, which means that it may invest a greater percentage of its assets than a diversified mutual fund in the securities of a limited number of issuers. The use of a non-diversified investment strategy may increase the volatility of the Fund’s investment performance, as the Fund may be more susceptible to risks associated with a single economic, political or regulatory event.

As with any mutual fund, there is no guarantee that the Fund will achieve its investment goal. You can find more information about the Fund’s investments and risks under the “Principal Investment Strategies and Risks” section of the Fund’s prospectus.
Risk Lose Money [Text] rr_RiskLoseMoney The Fund’s share price will fluctuate. You could lose money on your investment in the Fund, and the Fund could also return less than other investments. The Fund is subject to the principal risks listed below.
Risk Nondiversified Status [Text] rr_RiskNondiversifiedStatus Non-Diversification Risk: The Fund is non-diversified, which means that it may invest a greater percentage of its assets than a diversified mutual fund in the securities of a limited number of issuers. The use of a non-diversified investment strategy may increase the volatility of the Fund’s investment performance, as the Fund may be more susceptible to risks associated with a single economic, political or regulatory event.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading The Fund’s Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
The bar chart and performance table below illustrate some indication of the risks and volatility of an investment in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and by showing how the Fund’s average annual total returns for one year and since inception compare with the Russell 1000® Index. The bar chart does not reflect any sales charges, which would reduce your return. The performance table does reflect any applicable sales charge. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. More recent performance information is available at no cost by visiting TouchstoneInvestments.com or by calling 1.800.543.0407.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The bar chart and performance table below illustrate some indication of the risks and volatility of an investment in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and by showing how the Fund’s average annual total returns for one year and since inception compare with the Russell 1000® Index.
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone 1.800.543.0407
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress TouchstoneInvestments.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading Touchstone Large Cap Fund - Class A Shares Total Return as of December 31
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads The bar chart does not reflect any sales charges, which would reduce your return.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock
Best Quarter: Fourth Quarter 2016 6.16%
 
Worst Quarter: Third Quarter 2015 (7.98)%
The return of the Fund’s Class A shares for the nine months ended September 30, 2017 was 12.61%.
Year to Date Return, Label rr_YearToDateReturnLabel The return of the Fund’s Class A shares
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2017
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 12.61%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter:
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Dec. 31, 2016
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 6.16%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter:
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Sep. 30, 2015
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (7.98%)
Performance Table Heading rr_PerformanceTableHeading Average Annual Total Returns (for the periods ended December 31, 2015)
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes reflects no deduction for fees, expenses or taxes
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred The after-tax returns do not apply to shares held in an IRA, 401(k), or other tax-advantaged account.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown After-tax returns are only shown for Class A shares and after-tax returns for other classes will vary.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock
After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Your after-tax returns may differ from those shown and depend on your tax situation. The after-tax returns do not apply to shares held in an IRA, 401(k), or other tax-advantaged account. After-tax returns are only shown for Class A shares and after-tax returns for other classes will vary.
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Cap Fund | Russell 1000 Index  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Russell 1000® Index (reflects no deduction for fees, expenses or taxes)
1 Year rr_AverageAnnualReturnYear01 12.05%
Since Inception rr_AverageAnnualReturnSinceInception 7.19%
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Cap Fund | Touchstone International Small Cap Fund, Class C  
Prospectus: rr_ProspectusTable  
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Cap Fund | Touchstone Large Cap Fund, Class A  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TACLX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.70%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.62%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 1.57%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.45%) [4]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.12% [4]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2018
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 683
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 1,001
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 1,341
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 2,299
Annual Return 2015 rr_AnnualReturn2015 (3.81%)
Annual Return 2016 rr_AnnualReturn2016 8.74%
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 2.46%
Since Inception rr_AverageAnnualReturnSinceInception 2.40%
Inception Date rr_AverageAnnualReturnInceptionDate Jul. 09, 2014
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Cap Fund | Touchstone Large Cap Fund, Class A | After Taxes on Distributions  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Taxes on Distributions
1 Year rr_AverageAnnualReturnYear01 2.29%
Since Inception rr_AverageAnnualReturnSinceInception 2.26%
Inception Date rr_AverageAnnualReturnInceptionDate Jul. 09, 2014
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Cap Fund | Touchstone Large Cap Fund, Class A | After Taxes on Distributions and Sales  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Taxes on Distributions and Sale of Fund Shares
1 Year rr_AverageAnnualReturnYear01 1.54%
Since Inception rr_AverageAnnualReturnSinceInception 1.83%
Inception Date rr_AverageAnnualReturnInceptionDate Jul. 09, 2014
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Cap Fund | Touchstone Large Cap Fund, Class C  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TFCCX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.70%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.42%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 2.12%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.25%) [4]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.87% [4]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 290
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 640
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 1,116
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 2,432
Expense Example, No Redemption, 1 Year rr_ExpenseExampleNoRedemptionYear01 190
Expense Example, No Redemption, 3 Years rr_ExpenseExampleNoRedemptionYear03 640
Expense Example, No Redemption, 5 Years rr_ExpenseExampleNoRedemptionYear05 1,116
Expense Example, No Redemption, 10 Years rr_ExpenseExampleNoRedemptionYear10 $ 2,432
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 6.93%
Since Inception rr_AverageAnnualReturnSinceInception 4.14%
Inception Date rr_AverageAnnualReturnInceptionDate Jul. 09, 2014
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Cap Fund | Touchstone Large Cap Fund, Class Y  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TLCYX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.70%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.31%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 1.01%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.14%) [4]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 0.87% [4]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 89
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 308
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 544
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 1,224
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 8.96%
Since Inception rr_AverageAnnualReturnSinceInception 5.11%
Inception Date rr_AverageAnnualReturnInceptionDate Jul. 09, 2014
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Cap Fund | Touchstone Large Cap Fund, Institutional  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TLCIX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.70%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.21%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 0.91%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.14%) [4]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 0.77% [4]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 79
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 276
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 490
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 1,107
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 9.05%
Since Inception rr_AverageAnnualReturnSinceInception 5.21%
Inception Date rr_AverageAnnualReturnInceptionDate Jul. 09, 2014
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Company Growth Fund  
Prospectus: rr_ProspectusTable  
Risk/Return [Heading] rr_RiskReturnHeading TOUCHSTONE LARGE COMPANY GROWTH FUND SUMMARY
Objective [Heading] rr_ObjectiveHeading The Fund’s Investment Goal
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock
The Touchstone Large Company Growth Fund (the “Fund”) seeks to achieve long-term capital appreciation.
Expense [Heading] rr_ExpenseHeading The Fund’s Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock
This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.  You may qualify for sales charge discounts for Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 or more in the Touchstone Funds. More information about these and other discounts is available from your financial professional, in the section entitled “Choosing a Class of Shares” in the Fund’s prospectus and Statement of Additional Information ("SAI") on page 60 and 77, respectively, and, in Appendix A — Intermediary-Specific Sales Charge Waivers and Discounts to the Fund's prospectus.
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder Fees (fees paid directly from your investment)
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)
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading Portfolio Turnover.
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock
The Fund pays transaction costs, such as brokerage 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 the most recent fiscal year, the Fund's portfolio turnover rate was 55% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 55.00%
Expense Breakpoint Discounts [Text] rr_ExpenseBreakpointDiscounts You may qualify for sales charge discounts for Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 or more in the Touchstone Funds.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount $ 50,000
Expense Example [Heading] rr_ExpenseExampleHeading 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 example assumes that you invest $10,000 in the Fund for the time periods indicated and then, except as indicated, redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, that the Fund’s operating expenses remain the same and that all fee waivers or expense limits for the Fund will expire after one year.  Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption Assuming Redemption at End of Period
Expense Example, No Redemption, By Year, Caption [Text] rr_ExpenseExampleNoRedemptionByYearCaption Assuming No Redemption
Strategy [Heading] rr_StrategyHeading The Fund’s Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock
Under normal circumstances, the Fund will invest at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities of large capitalization issuers. Equity securities include, but are not limited to, common stocks, preferred stocks, securities convertible into common stocks, rights and warrants. The Fund’s portfolio generally will contain 25 to 35 equity securities. The Fund currently defines a large capitalization issuer as one that has a market capitalization of $10 billion or more at the time of purchase.

In addition, the Fund may invest up to 20% of its assets in equity securities of foreign issuers, including emerging markets, through, but not limited to, American Depositary Receipts ("ADRs") or other depositary receipts. The Fund is a non-diversified fund and may, from time to time, have significant exposure to one or more issuers, industries, geographic regions or sectors of the global economy.

DSM Capital Partners LLC ("DSM"), the Fund's Sub–Advisor, manages the Fund using a bottom-up, “idea-driven,” growth-style with a long-term (i.e., three-year) investment horizon. This means in general terms that DSM seeks to identify issuers which it believes exhibit certain quality characteristics. DSM generally sells an equity security when its projected future return becomes unattractive relative to the rest of the portfolio or the investable universe.
Risk [Heading] rr_RiskHeading The Fund’s Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock
The Fund’s share price will fluctuate. You could lose money on your investment in the Fund, and the Fund could also return less than other investments. The Fund is subject to the principal risks listed below.

Convertible Securities Risk: Convertible securities are subject to the risks of both debt securities and equity securities. The values of convertible securities tend to decline as interest rates rise and, due to the conversion feature, tend to vary with fluctuations in the market value of the underlying security.

Equity Securities Risk: The Fund is subject to the risk that stock prices will fall over short or extended periods of time. Individual companies may report poor results or be negatively affected by industry and/or economic trends and developments. The prices of securities issued by these companies may decline in response to such developments, which could result in a decline in the value of the Fund’s shares.

•
Large-Cap Risk: Large-cap companies may be unable to respond quickly to new competitive challenges, such as changes in technology and consumer tastes, and also may not be able to attain the high growth rate of successful smaller companies, especially during extended periods of economic expansion.

•
Preferred Stock Risk: In the event an issuer is liquidated or declares bankruptcy, the claims of owners of bonds take precedence over the claims of those who own preferred and common stock. If interest rates rise, the fixed dividend on preferred stocks may be less attractive, causing the price of preferred stocks to decline.

Foreign Securities Risk: Investing in foreign securities poses additional risks since political and economic events unique in a country or region will affect those markets and their issuers, while such events may not necessarily affect the U.S. economy or issuers located in the United States. In addition, investments in foreign securities are generally denominated in foreign currency. As a result, changes in the value of those currencies compared to the U.S. dollar may affect (positively or negatively) the value of the Fund's investments. There are also risks associated with foreign accounting standards, government regulation, market information, and clearance and settlement procedures. Foreign markets may be less liquid and more volatile than U.S. markets and offer less protection to investors.

•
Depositary Receipts Risk: Foreign receipts, which include ADRs, Global Depositary Receipts, and European Depositary Receipts, are securities that evidence ownership interests in a security or a pool of securities issued by a foreign issuer. The risks of depositary receipts include many risks associated with investing directly in foreign securities.

•
Emerging Markets Risk: Emerging markets may be more likely to experience political turmoil or rapid changes in market or economic conditions than more developed countries. In addition, the financial stability of issuers (including governments) in emerging market countries may be more precarious than that of issuers in other countries.

Growth-Investing Risk:  Growth-oriented funds may underperform when value investing is in favor, and growth stocks may be more volatile than other stocks because they are more sensitive to investor perceptions of the issuing company’s growth of earnings potential.

Management Risk: In managing the Fund’s portfolio, the Advisor engages one or more sub-advisors to make investment decisions for a portion of or the entire portfolio. There is a risk that the Advisor may be unable to identify and retain sub-advisors who achieve superior investment returns relative to other similar sub-advisors. 
 
Non-Diversification Risk: The Fund is non-diversified, which means that it may invest a greater percentage of its assets than a diversified mutual fund in the securities of a limited number of issuers. The use of a non-diversified investment strategy may increase the volatility of the Fund’s investment performance, as the Fund may be more susceptible to risks associated with a single economic, political or regulatory event.

Sector Focus Risk: A fund that focuses its investments in the securities of a particular market sector is subject to the risk that adverse circumstances will have a greater impact on the fund than a fund that does not focus its investments in a particular sector.

As with any mutual fund, there is no guarantee that the Fund will achieve its investment goal. You can find more information about the Fund’s investments and risks under the “Principal Investment Strategies and Risks” section of the Fund’s prospectus.
Risk Lose Money [Text] rr_RiskLoseMoney The Fund’s share price will fluctuate. You could lose money on your investment in the Fund, and the Fund could also return less than other investments. The Fund is subject to the principal risks listed below.
Risk Nondiversified Status [Text] rr_RiskNondiversifiedStatus Non-Diversification Risk: The Fund is non-diversified, which means that it may invest a greater percentage of its assets than a diversified mutual fund in the securities of a limited number of issuers. The use of a non-diversified investment strategy may increase the volatility of the Fund’s investment performance, as the Fund may be more susceptible to risks associated with a single economic, political or regulatory event.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading The Fund’s Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
The bar chart and the performance table below illustrate some indication of the risks and volatility of an investment in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and by showing how the Fund’s average annual total returns for one year, five years and since inception compare with the Russell 1000® Growth Index and the S&P 500® Index. The performance table does reflect any applicable sales charges. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. More recent performance information is available at no cost by visiting TouchstoneInvestments.com or by calling 1.800.543.0407.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The bar chart and the performance table below illustrate some indication of the risks and volatility of an investment in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and by showing how the Fund’s average annual total returns for one year, five years and since inception compare with the Russell 1000® Growth Index and the S&P 500® Index.
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone 1.800.543.0407
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress TouchstoneInvestments.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading Touchstone Large Company Growth Fund— Institutional Class Shares Total Return as of December 31
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock
Best Quarter: First Quarter 2012 17.13%
 
Worst Quarter: Third Quarter 2011 (14.47)%

The return of the Fund’s Institutional Class shares for the nine months ended September 30, 2017 was 31.15%.

Year to Date Return, Label rr_YearToDateReturnLabel The return of the Fund’s Institutional Class shares
Performance Table Heading rr_PerformanceTableHeading Average Annual Total Returns for the periods ended December 31, 2015*
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes reflects no deductions for fees, expenses or taxes
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Your after-tax returns may differ from those shown and depend on your tax situation. The after-tax returns do not apply to shares held in an IRA, 401(k), or other tax-advantaged account.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown After-tax returns are only shown for Institutional Class shares and after-tax returns for other classes will vary.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock
Before the Fund commenced operations, all of the assets and liabilities of the DSM Large Cap Growth Fund (the “Predecessor Fund”) were transferred to the Fund in a tax-free reorganization (the “Reorganization”). The Reorganization occurred on August 15, 2016. As a result of the Reorganization, the Fund assumed the performance and accounting history of the Predecessor Fund. For more information on the prior history of the Fund, please see the section entitled “The Trust” in the Fund’s Statement of Additional Information.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Your after-tax returns may differ from those shown and depend on your tax situation. The after-tax returns do not apply to shares held in an IRA, 401(k), or other tax-advantaged account. After-tax returns are only shown for Institutional Class shares and after-tax returns for other classes will vary.

The inception dates of Class A shares, Class C shares, Class Y shares, and Institutional Class shares were August 15, 2016, August 15, 2016, August 15, 2016 and August 28, 2009, respectively. The performance of each share class was calculated using the historical performance of Institutional Class shares for periods prior to August 15, 2016. Performance for these periods has been restated to reflect the impact of the fees and expenses applicable to Class A, Class C and Class Y shares
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Company Growth Fund | Russell 1000 Growth Index  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Russell 1000® Growth Index (reflects no deductions for fees, expenses or taxes)
1 Year rr_AverageAnnualReturnYear01 7.08%
5 Years rr_AverageAnnualReturnYear05 14.50%
Since Inception rr_AverageAnnualReturnSinceInception 14.06%
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Company Growth Fund | S&P 500® Index  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel S&P 500® Index (reflects no deductions for fees, expenses or taxes)
1 Year rr_AverageAnnualReturnYear01 11.96%
5 Years rr_AverageAnnualReturnYear05 14.66%
Since Inception rr_AverageAnnualReturnSinceInception 13.51%
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Company Growth Fund | Touchstone Large Company Growth Fund, Class A  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TSAGX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.75%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 10.14%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 11.14%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (9.91%) [5]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.23% [5],[6]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2018
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 693
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 2,740
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 4,544
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 8,169
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (8.43%)
5 Years rr_AverageAnnualReturnYear05 11.51%
Since Inception rr_AverageAnnualReturnSinceInception 11.62%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 15, 2016
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Company Growth Fund | Touchstone Large Company Growth Fund, Class C  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TCGLX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.75%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 255.27%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 257.02%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (255.04%) [5]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.98% [5],[6]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 301
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 13,440
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 13,440
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 13,440
Expense Example, No Redemption, 1 Year rr_ExpenseExampleNoRedemptionYear01 201
Expense Example, No Redemption, 3 Years rr_ExpenseExampleNoRedemptionYear03 13,440
Expense Example, No Redemption, 5 Years rr_ExpenseExampleNoRedemptionYear05 13,440
Expense Example, No Redemption, 10 Years rr_ExpenseExampleNoRedemptionYear10 $ 13,440
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (4.53%)
5 Years rr_AverageAnnualReturnYear05 12.00%
Since Inception rr_AverageAnnualReturnSinceInception 11.69%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 15, 2016
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Company Growth Fund | Touchstone Large Company Growth Fund, Class Y  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TLGYX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.75%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.37%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 1.12%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.14%) [5]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 0.98% [5],[6]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 100
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 342
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 603
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 1,351
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (2.64%)
5 Years rr_AverageAnnualReturnYear05 13.11%
Since Inception rr_AverageAnnualReturnSinceInception 12.75%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 15, 2016
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Company Growth Fund | Touchstone Large Company Growth Fund, Institutional Class  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol DSMLX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.75%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.27%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 1.02%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.14%) [5]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 0.88% [5],[6]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 90
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 311
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 550
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 1,235
Annual Return 2010 rr_AnnualReturn2010 22.36%
Annual Return 2011 rr_AnnualReturn2011 (1.14%)
Annual Return 2012 rr_AnnualReturn2012 18.96%
Annual Return 2013 rr_AnnualReturn2013 35.58%
Annual Return 2014 rr_AnnualReturn2014 9.77%
Annual Return 2015 rr_AnnualReturn2015 7.49%
Annual Return 2016 rr_AnnualReturn2016 (2.59%)
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2017
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 31.15%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter:
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Mar. 31, 2012
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 17.13%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter:
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Sep. 30, 2011
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (14.47%)
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (2.59%)
5 Years rr_AverageAnnualReturnYear05 13.14%
Since Inception rr_AverageAnnualReturnSinceInception 12.77%
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Company Growth Fund | Touchstone Large Company Growth Fund, Institutional Class | After Taxes on Distributions  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Federal Income Taxes on Distributions
1 Year rr_AverageAnnualReturnYear01 (3.40%)
5 Years rr_AverageAnnualReturnYear05 12.13%
Since Inception rr_AverageAnnualReturnSinceInception 11.88%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 28, 2009
TOUCHSTONE STRATEGIC TRUST | Touchstone Large Company Growth Fund | Touchstone Large Company Growth Fund, Institutional Class | After Taxes on Distributions and Sales  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Federal Income Taxes on Distributions and Sale of Fund Shares
1 Year rr_AverageAnnualReturnYear01 (0.77%)
5 Years rr_AverageAnnualReturnYear05 10.39%
Since Inception rr_AverageAnnualReturnSinceInception 10.28%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 28, 2009
TOUCHSTONE STRATEGIC TRUST | Touchstone Ohio Tax-Free Bond Fund  
Prospectus: rr_ProspectusTable  
Risk/Return [Heading] rr_RiskReturnHeading TOUCHSTONE OHIO TAX-FREE BOND FUND SUMMARY
Objective [Heading] rr_ObjectiveHeading The Fund’s Investment Goal
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock
The Touchstone Ohio Tax-Free Bond Fund (the “Fund”) seeks the highest level of interest income exempt from federal income tax and Ohio personal income tax, consistent with the protection of capital.
Expense [Heading] rr_ExpenseHeading The Fund’s Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock
This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts for Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 or more in the Touchstone Funds. More information about these and other discounts is available from your financial professional, in the section entitled “Choosing a Class of Shares” in the Fund’s prospectus and Statement of Additional Information ("SAI") on page 60 and 77, respectively, and, in Appendix A — Intermediary-Specific Sales Charge Waivers and Discounts to the Fund's prospectus.
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder Fees (fees paid directly from your investment)
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)
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading Portfolio Turnover.
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock
The Fund pays transaction costs, such as brokerage 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 the most recent fiscal year, the Fund's portfolio turnover rate was 34% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 34.00%
Expense Example [Heading] rr_ExpenseExampleHeading 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 example assumes that you invest $10,000 in the Fund for the time periods indicated and then, except as indicated, redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year. that the Fund’s operating expenses remain the same and that all fee waivers or expense limits for the Fund will expire after one year. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption Assuming Redemption at End of Period
Expense Example, No Redemption, By Year, Caption [Text] rr_ExpenseExampleNoRedemptionByYearCaption Assuming No Redemption
Strategy [Heading] rr_StrategyHeading The Fund’s Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock
Under normal circumstances, the Fund invests at least 80% of its assets in high-quality, long-term Ohio municipal obligations, including general obligation bonds, revenue bonds, and industrial development bonds. High-quality, long-term Ohio municipal obligations are, for purposes of this Fund, considered to be obligations rated within the three highest rating categories, with remaining maturities of three years or more. The Fund is a non-diversified fund and may, from time to time, have significant exposure to one or more issuers, industries, geographic regions or sectors.

The Fund may also purchase Ohio municipal obligations and other securities rated within the four highest rating categories. The Fund may purchase unrated obligations that Fort Washington Investment Advisors, Inc., the Fund's sub-advisor (“Fort Washington” or “Sub-Advisor”), determines to be of comparable quality. If a security’s rating is reduced below the four highest rating categories, the security will be sold in a timely manner. A security may also be sold due to changes in market conditions or the Sub-Advisor's outlook.
 
The Fund has a fundamental investment policy that under normal circumstances at least 80% of the income it distributes will be exempt from federal income tax, including the federal alternative minimum tax, and Ohio personal income tax. This fundamental policy may not be changed without the approval of the Fund’s shareholders.
Risk [Heading] rr_RiskHeading The Fund’s Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock
The Fund’s share price will fluctuate. You could lose money on your investment in the Fund, and the Fund could also return less than other investments. The Fund is subject to the principal risks listed below.
 
Fixed-Income Risk: The market value of the Fund’s fixed-income securities responds to economic developments, particularly interest rate changes, as well as to perceptions about the creditworthiness of individual issuers, including governments. Generally, the Fund’s fixed-income securities will decrease in value if interest rates rise and increase in value if interest rates fall. Normally, the longer the maturity or duration of the fixed-income securities the Fund owns, the more sensitive the value of the Fund’s shares will be to changes in interest rates.
 
•
Credit Risk: The fixed-income securities in the Fund’s portfolio are subject to the possibility that a deterioration, whether sudden or gradual, in the financial condition of an issuer, or a deterioration in general economic conditions, could cause an issuer to fail to make timely payments of principal or interest, when due. This may cause the issuer’s securities to decline in value.
 
•
Interest Rate Risk: In general, when interest rates rise, the prices of debt securities fall, and when interest rates fall, the prices of debt securities rise. The price volatility of a debt security also depends on its maturity. Longer-term securities are generally more volatile, so the longer the average maturity or duration of these securities, the greater their price risk.
 
•
Investment-Grade Debt Securities Risk: Investment-grade debt securities may be downgraded by a NRSRO to below-investment-grade status, which would increase the risk of holding these securities. Investment-grade debt securities rated in the lowest rating category by a NRSRO involve a higher degree of risk than fixed-income securities with higher credit ratings.

Management Risk: In managing the Fund’s portfolio, the Advisor engages one or more sub-advisors to make investment decisions for a portion of or the entire portfolio. There is a risk that the Advisor may be unable to identify and retain sub-advisors who achieve superior investment returns relative to other similar sub-advisors.
 
Municipal Securities Risk:  The value of municipal securities may be affected by uncertainties in the municipal market related to legislation or litigation involving the taxation of municipal securities or the rights of municipal securities holders in the event of bankruptcy. In addition, a downturn in the national economy may negatively impact the economic performance of issuers of municipal securities, and may increase the likelihood that issuers of securities in which the Fund may invest may be unable to meet their obligations. Also, some municipal obligations may be backed by a letter of credit issued by a bank or other financial institution. Adverse developments affecting banks or other financial institutions could have a negative effect on the value of the Fund’s portfolio securities.
 
Non-Diversification Risk: The Fund is non-diversified, which means that it may invest a greater percentage of its assets than a diversified mutual fund in the securities of a limited number of issuers. The use of a non-diversified investment strategy may increase the volatility of the Fund’s investment performance, as the Fund may be more susceptible to risks associated with a single economic, political or regulatory event.
 
Prepayment Risk: The risk that a debt security may be paid off and proceeds invested earlier than anticipated. Prepayment impacts both the interest rate sensitivity of the underlying asset, such as an asset-backed or mortgage-backed security and its cash flow projections. Therefore, prepayment risk may make it difficult to calculate the average duration of the Fund’s asset- or mortgage-backed securities which in turn would make it difficult to assess the interest rate risk of the Fund.
 
Sector Focus Risk: A fund that focuses its investments in the securities of a particular market sector is subject to the risk that adverse circumstances will have a greater impact on the fund than a fund that does not focus its investments in a particular sector.
 
State Risk: Political and economic conditions in the State of Ohio may impact the value of Ohio municipal obligations. The Fund may lose value due to decreased economic growth, increased unemployment and decreased tax revenue in the State of Ohio.
 
As with any mutual fund, there is no guarantee that the Fund will achieve its investment goal. You can find more information about the Fund’s investments and risks under the “Principal Investment Strategies and Risks” section of the Fund’s prospectus.
Risk Nondiversified Status [Text] rr_RiskNondiversifiedStatus Non-Diversification Risk: The Fund is non-diversified, which means that it may invest a greater percentage of its assets than a diversified mutual fund in the securities of a limited number of issuers. The use of a non-diversified investment strategy may increase the volatility of the Fund’s investment performance, as the Fund may be more susceptible to risks associated with a single economic, political or regulatory event.
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
The Fund’s Performance
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone 1.800.543.0407
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress TouchstoneInvestments.com
Bar Chart [Heading] rr_BarChartHeading Touchstone Ohio Tax-Free Bond Fund — Class A Shares Total Return as of December 31
Bar Chart Narrative [Text Block] rr_BarChartNarrativeTextBlock
On December 16, 2016, the Touchstone Ohio Tax-Free Bond Fund, a series of Touchstone Tax-Free Trust (the "Predecessor Fund"), was reorganized into the Fund. As a result of the reorganization, the performance and accounting history of the Predecessor Fund were assumed by the Fund.  Financial and performance information prior to December 16, 2016 is that of the Predecessor Fund.

The bar chart and the performance table below illustrate some indication of the risks and volatility of an investment in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and by showing how the Fund’s average annual total returns for one year, five years, and ten years compare with the Bloomberg Barclays Municipal Bond Index. The bar chart does not reflect any sales charges, which would reduce your return. The performance table does reflect any applicable sales charges. Past performance of the Fund (before and after taxes) does not necessarily indicate how the Fund will perform in the future. More recent performance information is available at no cost by visiting TouchstoneInvestments.com or by calling 1.800.543.0407.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock
Best Quarter: Third Quarter 2009 5.43%
 
Worst Quarter: Fourth Quarter 2010 (3.88)%

The return of the Fund’s Class A shares for the nine months ended September 30, 2017 was 3.15%.
Performance Table Heading rr_PerformanceTableHeading Average Annual Total Returns for the periods ended December 31, 2015*
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes reflects no deductions for fees, expenses or taxes
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock
The inception dates of Class A shares, Class C shares, Class Y shares, and Institutional Class shares were April 1, 1985, November 1, 1993, August 30, 2016 and August 30, 2016, respectively. Class Y and Institutional Class shares’ performance was calculated using the historical performance of Class A shares for the periods prior to August 30, 2016. Performance for these periods has been restated to reflect the impact of the fees and expenses applicable to Class Y and Institutional Class shares.
Performance Table Footnotes rr_PerformanceTableFootnotesTextBlock
After–tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Your after–tax returns may differ from those shown and depend on your tax situation. The after–tax returns do not apply to shares held in an IRA, 401(k), or other tax–advantaged account. After–tax returns are only shown for Class A shares and after–tax returns for other classes will vary.
TOUCHSTONE STRATEGIC TRUST | Touchstone Ohio Tax-Free Bond Fund | Bloomberg Barclays Municipal Bond Index  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Bloomberg Barclays Municipal Bond Index (reflects no deductions for fees, expenses or taxes)
1 Year rr_AverageAnnualReturnYear01 0.25%
5 Years rr_AverageAnnualReturnYear05 3.28%
10 Years rr_AverageAnnualReturnYear10 4.25%
TOUCHSTONE STRATEGIC TRUST | Touchstone Ohio Tax-Free Bond Fund | Touchstone Ohio Tax-Free Bond Fund Class A  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TOHAX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice 4.75%
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.50%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.38%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 1.13%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.28%) [7]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 0.85% [7]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2018
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 558
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 791
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 1,042
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 1,760
Annual Return 2007 rr_AnnualReturn2007 3.01%
Annual Return 2008 rr_AnnualReturn2008 (1.28%)
Annual Return 2009 rr_AnnualReturn2009 10.61%
Annual Return 2010 rr_AnnualReturn2010 1.06%
Annual Return 2011 rr_AnnualReturn2011 8.61%
Annual Return 2012 rr_AnnualReturn2012 7.44%
Annual Return 2013 rr_AnnualReturn2013 (2.29%)
Annual Return 2014 rr_AnnualReturn2014 8.25%
Annual Return 2015 rr_AnnualReturn2015 2.57%
Annual Return 2016 rr_AnnualReturn2016 0.18%
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2017
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 3.15%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter:
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Mar. 31, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 5.43%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter:
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2010
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (3.88%)
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (4.60%)
5 Years rr_AverageAnnualReturnYear05 2.15%
10 Years rr_AverageAnnualReturnYear10 3.22%
TOUCHSTONE STRATEGIC TRUST | Touchstone Ohio Tax-Free Bond Fund | Touchstone Ohio Tax-Free Bond Fund Class A | After Taxes on Distributions  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Taxes on Distributions
1 Year rr_AverageAnnualReturnYear01 (4.64%)
5 Years rr_AverageAnnualReturnYear05 2.10%
10 Years rr_AverageAnnualReturnYear10 3.16%
TOUCHSTONE STRATEGIC TRUST | Touchstone Ohio Tax-Free Bond Fund | Touchstone Ohio Tax-Free Bond Fund Class A | After Taxes on Distributions and Sales  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Taxes on Distributions and Sale of Fund Shares
1 Year rr_AverageAnnualReturnYear01 (1.34%)
5 Years rr_AverageAnnualReturnYear05 2.41%
10 Years rr_AverageAnnualReturnYear10 3.28%
TOUCHSTONE STRATEGIC TRUST | Touchstone Ohio Tax-Free Bond Fund | Touchstone Ohio Tax-Free Bond Fund Class C  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TOHCX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.50%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.53%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 2.03%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.43%) [7]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.60% [7]
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 263
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 595
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 1,054
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 2,324
Expense Example, No Redemption, 1 Year rr_ExpenseExampleNoRedemptionYear01 163
Expense Example, No Redemption, 3 Years rr_ExpenseExampleNoRedemptionYear03 595
Expense Example, No Redemption, 5 Years rr_ExpenseExampleNoRedemptionYear05 1,054
Expense Example, No Redemption, 10 Years rr_ExpenseExampleNoRedemptionYear10 $ 2,324
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (1.63%)
5 Years rr_AverageAnnualReturnYear05 2.38%
10 Years rr_AverageAnnualReturnYear10 2.95%
TOUCHSTONE STRATEGIC TRUST | Touchstone Ohio Tax-Free Bond Fund | Touchstone Ohio Tax-Free Bond Fund Class Y  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TOHYX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.50%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 297.77%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 298.27%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (297.67%) [7]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 0.60% [7]
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 61
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 15,631
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 15,631
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 15,631
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 0.27%
5 Years rr_AverageAnnualReturnYear05 3.17%
10 Years rr_AverageAnnualReturnYear10 3.73%
TOUCHSTONE STRATEGIC TRUST | Touchstone Ohio Tax-Free Bond Fund | Touchstone Ohio-Tax Free Bond Fund Institutional Class  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TOHIX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.50%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 297.76%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 298.26%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (297.71%) [7]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 0.55% [7]
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 56
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 15,633
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 15,633
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 15,633
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 0.26%
5 Years rr_AverageAnnualReturnYear05 3.17%
10 Years rr_AverageAnnualReturnYear10 3.73%
TOUCHSTONE STRATEGIC TRUST | Touchstone Small Cap Value Opportunities Fund  
Prospectus: rr_ProspectusTable  
Risk/Return [Heading] rr_RiskReturnHeading TOUCHSTONE SMALL CAP VALUE OPPORTUNITIES FUND SUMMARY
Objective [Heading] rr_ObjectiveHeading The Fund’s Investment Goal
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock
The Touchstone Small Cap Value Opportunities Fund (the “Fund”) seeks to provide investors with long-term capital growth.
Expense [Heading] rr_ExpenseHeading The Fund’s Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock
This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts for Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 or more in the Touchstone Funds. More information about these and other discounts is available from your financial professional, in the section entitled “Choosing a Class of Shares” in the Fund’s prospectus and Statement of Additional Information ("SAI") on page 60 and 77, respectively, and, in Appendix A — Intermediary-Specific Sales Charge Waivers and Discounts to the Fund's prospectus.
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder Fees (fees paid directly from your investment)
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)
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading Portfolio Turnover.
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock
The Fund pays transaction costs, such as brokerage 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 the most recent fiscal year, the Fund's portfolio turnover rate was 59% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 59.00%
Expense Breakpoint Discounts [Text] rr_ExpenseBreakpointDiscounts You may qualify for sales charge discounts for Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 or more in the Touchstone Funds.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount $ 50,000
Expense Example [Heading] rr_ExpenseExampleHeading 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 example assumes that you invest $10,000 in the Fund for the time periods indicated and then, except as indicated, redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, that the Fund’s operating expenses remain the same and that all fee waivers or expense limits for the Fund will expire after one year. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption Assuming Redemption at End of Period
Expense Example, No Redemption, By Year, Caption [Text] rr_ExpenseExampleNoRedemptionByYearCaption Assuming No Redemption
Strategy [Heading] rr_StrategyHeading The Fund’s Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock
The Fund normally invests at least 80% of its assets in equity securities of small-cap companies. For purposes of this Fund, small-cap companies are those companies with market capitalizations at the time of investment similar to the market capitalizations of companies in the Russell 2000® Value Index (between approximately $41 million and $10.9 billion as of September 30, 2017). The size of the companies in the Russell 2000® Value Index will change with market conditions. Equity securities include common and preferred stocks. The Fund may invest up to 15% of its assets in foreign equity securities, including American Depositary Receipts ("ADRs") or other depositary receipts.
 
Thompson, Siegel & Walmsley LLC (“TSW”), the Fund’s sub-advisor, primarily invests in common stocks. TSW seeks to invest in companies it believes present a value or potential worth that is not recognized by prevailing market prices or that have experienced some fundamental changes and are intrinsically undervalued by the investment community. TSW’s analysts also explore numerous factors that might affect the outlook for a company. They evaluate publicly available information, including, but not limited to, sell-side research, company filings, and trade periodicals. The analysts may speak with company management to hear their perspectives and outlook on the pertinent business issues. TSW's investment process may result in exposure to one or a group of related sectors.
 
TSW generally considers selling a security when the catalyst for the investment is no longer valid, when TSW believes that another stock will have a higher expected return, or for portfolio risk management. The Fund generally engages in active and frequent trading of portfolio securities as part of its principal investment strategy.
Risk [Heading] rr_RiskHeading The Fund’s Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

Equity Securities Risk: The Fund is subject to the risk that stock prices will fall over short or extended periods of time. Individual companies may report poor results or be negatively affected by industry and/or economic trends and developments. The prices of securities issued by these companies may decline in response to such developments, which could result in a decline in the value of the Fund’s shares.
 
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Preferred Stock Risk: In the event an issuer is liquidated or declares bankruptcy, the claims of owners of bonds take precedence over the claims of those who own preferred and common stock. If interest rates rise, the fixed dividend on preferred stocks may be less attractive, causing the price of preferred stocks to decline.
 
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Small-Cap Risk:  Stocks of smaller companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies. Small companies may have limited product lines or financial resources and may be dependent upon a small or inexperienced management group.
 
Foreign Securities Risk: Investing in foreign securities poses additional risks since political and economic events unique in a country or region will affect those markets and their issuers, while such events may not necessarily affect the U.S. economy or issuers located in the United States. In addition, investments in foreign securities are generally denominated in foreign currency. As a result, changes in the value of those currencies compared to the U.S. dollar may affect (positively or negatively) the value of the Fund's investments. There are also risks associated with foreign accounting standards, government regulation, market information, and clearance and settlement procedures. Foreign markets may be less liquid and more volatile than U.S. markets and offer less protection to investors.
 
•
Depositary Receipts Risk: Foreign receipts, which include ADRs, Global Depositary Receipts, and European Depositary Receipts, are securities that evidence ownership interests in a security or a pool of securities issued by a foreign issuer. The risks of depositary receipts include many risks associated with investing directly in foreign securities.
 
Management Risk: In managing the Fund’s portfolio, the Advisor engages one or more sub-advisors to make investment decisions for a portion of or the entire portfolio. There is a risk that the Advisor may be unable to identify and retain sub-advisors who achieve superior investment returns relative to other similar sub-advisors.
 
Portfolio Turnover Risk: Frequent and active trading may result in greater expenses to the Fund, which may lower the Fund's performance and may result in the realization of substantial capital gains, including net short-term capital gains. As a result, high portfolio turnover may reduce the Fund's returns.
 
Sector Focus Risk: A fund that focuses its investments in the securities of a particular market sector is subject to the risk that adverse circumstances will have a greater impact on the fund than a fund that does not focus its investments in a particular sector.

Value Investing Risk: Value investing presents the risk that the Fund’s security holdings may never reach their full market value because the market fails to recognize what the portfolio managers consider the true business value or because the portfolio managers have misjudged those values.
 
As with any mutual fund, there is no guarantee that the Fund will achieve its investment goal. You can find more information about the Fund’s investments and risks under the “Principal Investment Strategies and Risks” section of the Fund’s prospectus.
Risk Lose Money [Text] rr_RiskLoseMoney The Fund’s share price will fluctuate. You could lose money on your investment in the Fund, and the Fund could also return less than other investments. The Fund is subject to the principal risks listed below.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading The Fund’s Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
The bar chart and performance table below illustrate some indication of the risks and volatility of an investment in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and by showing how the Fund’s average annual total returns for one year, five years, and ten years compare with the Russell 2000® Value Index. The bar chart does not reflect any sales charges, which would reduce your return.The performance table does reflect any applicable sales charges. Past performance of the Fund (before and after taxes) does not necessarily indicate how the Fund will perform in the future. More recent performance information is available at no cost by visiting TouchstoneInvestments.com or by calling 1.800.543.0407.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The bar chart and performance table below illustrate some indication of the risks and volatility of an investment in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and by showing how the Fund’s average annual total returns for one year, five years, and ten years compare with the Russell 2000® Value Index.
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone 1.800.543.0407
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress TouchstoneInvestments.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Past performance of the Fund (before and after taxes) does not necessarily indicate how the Fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading Touchstone Small Cap Value Opportunities Fund — Class A Shares Total Return as of December 31
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads The bar chart does not reflect any sales charges, which would reduce your return.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock
Best Quarter: Third Quarter 2009 17.60%
 
Worst Quarter: Fourth Quarter 2008 (24.42)%
 
The return of the Fund’s Class A shares for the nine months ended September 30, 2017 was (0.46)%
Performance Table Heading rr_PerformanceTableHeading Average Annual Total Returns (for the periods ended December 31, 2015)
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes reflects no deductions for fees, expenses or taxes
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred The after-tax returns do not apply to shares held in an IRA, 401(k), or other tax-advantaged account.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown After-tax returns are only shown for Class A shares and after-tax returns for other classes will vary.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock
Before the Fund commenced operations, all of the assets and liabilities of the Old Mutual TS&W Small Cap Value Fund (the “Predecessor Fund”) were transferred to the Fund in a tax-free reorganization (the “Reorganization”). The Reorganization occurred on April 16, 2012. As a result of the Reorganization, the Fund assumed the performance and accounting history of the Predecessor Fund prior to the date of the Reorganization. For more information on the prior history of the Fund, please see the section entitled “The Trust” in the Fund’s SAI.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Your after-tax returns may differ from those shown and depend on your tax situation. The after-tax returns do not apply to shares held in an IRA, 401(k), or other tax-advantaged account. After-tax returns are only shown for Class A shares and after-tax returns for other classes will vary.
 
The inception dates of Class A shares, Class C shares, Class Y shares, and Institutional Class shares were July 31, 2003, April 12, 2012, July 25, 2003 and December 9, 2008, respectively. Class C and Institutional Class shares’ performance was calculated using the historical performance of Class Y shares for the periods prior to April 12, 2012 and December 9, 2008, respectively. Performance for these periods has been restated to reflect the impact of the fees and expenses applicable to Class C and Institutional Class shares.
TOUCHSTONE STRATEGIC TRUST | Touchstone Small Cap Value Opportunities Fund | Russell 2000® Value Index  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Russell 2000® Value Index (reflects no deduction for fees, expenses or taxes)
1 Year rr_AverageAnnualReturnYear01 31.74%
5 Years rr_AverageAnnualReturnYear05 15.07%
10 Years rr_AverageAnnualReturnYear10 6.26%
TOUCHSTONE STRATEGIC TRUST | Touchstone Small Cap Value Opportunities Fund | Touchstone Small Cap Value Opportunities Fund, Class A  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TSOAX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.95%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.83%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 2.03%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.60%) [8]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.43% [8]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2018
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 712
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 1,120
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 1,553
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 2,753
Annual Return 2007 rr_AnnualReturn2007 1.09%
Annual Return 2008 rr_AnnualReturn2008 (32.49%)
Annual Return 2009 rr_AnnualReturn2009 20.40%
Annual Return 2010 rr_AnnualReturn2010 16.21%
Annual Return 2011 rr_AnnualReturn2011 (2.15%)
Annual Return 2012 rr_AnnualReturn2012 14.46%
Annual Return 2013 rr_AnnualReturn2013 46.09%
Annual Return 2014 rr_AnnualReturn2014 6.11%
Annual Return 2015 rr_AnnualReturn2015 (10.77%)
Annual Return 2016 rr_AnnualReturn2016 15.89%
Year to Date Return, Label rr_YearToDateReturnLabel The return of the Fund’s Class A shares
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn (0.46%)
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter:
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 17.60%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter:
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (24.42%)
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 9.23%
5 Years rr_AverageAnnualReturnYear05 11.57%
10 Years rr_AverageAnnualReturnYear10 4.92%
Inception Date rr_AverageAnnualReturnInceptionDate Jul. 31, 2003
TOUCHSTONE STRATEGIC TRUST | Touchstone Small Cap Value Opportunities Fund | Touchstone Small Cap Value Opportunities Fund, Class A | After Taxes on Distributions  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Taxes on Distributions
1 Year rr_AverageAnnualReturnYear01 9.20%
5 Years rr_AverageAnnualReturnYear05 8.42%
10 Years rr_AverageAnnualReturnYear10 2.88%
Inception Date rr_AverageAnnualReturnInceptionDate Jul. 31, 2003
TOUCHSTONE STRATEGIC TRUST | Touchstone Small Cap Value Opportunities Fund | Touchstone Small Cap Value Opportunities Fund, Class A | After Taxes on Distributions and Sales  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Taxes on Distributions and Sale of Fund Shares
1 Year rr_AverageAnnualReturnYear01 5.25%
5 Years rr_AverageAnnualReturnYear05 8.42%
10 Years rr_AverageAnnualReturnYear10 3.48%
Inception Date rr_AverageAnnualReturnInceptionDate Jul. 31, 2003
TOUCHSTONE STRATEGIC TRUST | Touchstone Small Cap Value Opportunities Fund | Touchstone Small Cap Value Opportunities Fund, Class C  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TSOCX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.95%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 1.58%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 3.53%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (1.35%) [8]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 2.18% [8]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 321
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 958
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 1,716
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 3,712
Expense Example, No Redemption, 1 Year rr_ExpenseExampleNoRedemptionYear01 221
Expense Example, No Redemption, 3 Years rr_ExpenseExampleNoRedemptionYear03 958
Expense Example, No Redemption, 5 Years rr_ExpenseExampleNoRedemptionYear05 1,716
Expense Example, No Redemption, 10 Years rr_ExpenseExampleNoRedemptionYear10 $ 3,712
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 13.97%
5 Years rr_AverageAnnualReturnYear05 12.33%
10 Years rr_AverageAnnualReturnYear10 4.88%
Inception Date rr_AverageAnnualReturnInceptionDate Apr. 12, 2012
TOUCHSTONE STRATEGIC TRUST | Touchstone Small Cap Value Opportunities Fund | Touchstone Small Cap Value Opportunities Fund, Institutional  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TSOIX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.95%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.35%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 1.30%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.20%) [8]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.10% [8]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 112
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 392
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 694
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 1,550
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 16.28%
5 Years rr_AverageAnnualReturnYear05 13.33%
10 Years rr_AverageAnnualReturnYear10 5.62%
Inception Date rr_AverageAnnualReturnInceptionDate Dec. 09, 2008
TOUCHSTONE STRATEGIC TRUST | Touchstone Small Cap Value Opportunities Fund | Touchstone Small Cap Value Opportunities Fund, Class Y  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TSOYX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.95%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.34%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 1.29%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.11%) [8]
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.18% [8]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 120
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 398
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 697
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 1,547
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 16.16%
5 Years rr_AverageAnnualReturnYear05 13.22%
10 Years rr_AverageAnnualReturnYear10 5.82%
Inception Date rr_AverageAnnualReturnInceptionDate Jul. 25, 2003
TOUCHSTONE STRATEGIC TRUST | Touchstone Value Fund  
Prospectus: rr_ProspectusTable  
Risk/Return [Heading] rr_RiskReturnHeading TOUCHSTONE VALUE FUND SUMMARY
Objective [Heading] rr_ObjectiveHeading The Fund’s Investment Goal
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock
The Touchstone Value Fund (the “Fund”) seeks to provide investors with long-term capital growth.
Expense [Heading] rr_ExpenseHeading The Fund’s Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock
This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts for Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 or more in the Touchstone Funds. More information about these and other discounts is available from your financial professional, in the section entitled “Choosing a Class of Shares” in the Fund’s prospectus and Statement of Additional Information ("SAI") on page 60 and 77, respectively, and, in Appendix A — Intermediary-Specific Sales Charge Waivers and Discounts to the Fund's prospectus.
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder Fees (fees paid directly from your investment)
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)
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading Portfolio Turnover.
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock
The Fund pays transaction costs, such as brokerage 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 the most recent fiscal year, the Fund's portfolio turnover rate was 29% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 29.00%
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount $ 50,000
Expense Example [Heading] rr_ExpenseExampleHeading 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.
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption The example assumes that you invest $10,000 in the Fund for the time periods indicated and then, except as indicated, redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, that the Fund’s operating expenses remain the same and that all fee waivers or expense limits for the Fund will expire after one year. Although your actual costs may be higher or lower, based on these assumptions your costs would be:Assuming Redemption at End of Period
Expense Example, No Redemption, By Year, Caption [Text] rr_ExpenseExampleNoRedemptionByYearCaption Assuming No Redemption
Strategy [Heading] rr_StrategyHeading The Fund’s Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock
The Fund normally invests in equity securities of large- and mid-cap companies (generally, companies with market capitalizations of approximately $2.5 billion or higher) that the Fund’s sub-advisor, Barrow, Hanley, Mewhinney & Strauss, LLC (“Barrow Hanley”) believes are undervalued. As part of this strategy, the Fund may invest up to 15% of its assets in foreign equity securities. Equity securities include common and preferred stocks and depositary receipts.  Barrow Hanley uses traditional methods of stock selection — research and analysis — to identify securities it believes are undervalued and searches for companies that have price to earnings and price to book ratios below the market and that have above average dividend yields.
 
Although the Fund may also focus its investments within certain sectors, Barrow Hanley uses risk management tools to prevent over-exposure to particular market segments. Barrow Hanley is a “bottom-up” value manager, meaning it analyzes the fundamentals of companies one at a time rather than focusing on broader market themes.
 
Barrow Hanley generally considers selling a security when it reaches fair value estimate, when earnings forecasts do not appear to justify the current price, when there has been or there is an expectation of an adverse change in the company’s fundamentals, or when other investment opportunities appear more attractive.
Risk [Heading] rr_RiskHeading The Fund’s Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock
The Fund’s share price will fluctuate. You could lose money on your investment in the Fund, and the Fund could also return less than other investments. The Fund is subject to the principal risks listed below.

Equity Securities Risk: The Fund is subject to the risk that stock prices will fall over short or extended periods of time. Individual companies may report poor results or be negatively affected by industry and/or economic trends and developments. The prices of securities issued by these companies may decline in response to such developments, which could result in a decline in the value of the Fund’s shares.

•
Large-Cap Risk: Large-cap companies may be unable to respond quickly to new competitive challenges, such as changes in technology and consumer tastes, and also may not be able to attain the high growth rate of successful smaller companies, especially during extended periods of economic expansion.
 
•
Mid-Cap Risk:  Stocks of mid-sized companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies. Mid-sized companies may have limited product lines or financial resources, and may be dependent upon a particular niche of the market.

•
Preferred Stock Risk: In the event an issuer is liquidated or declares bankruptcy, the claims of owners of bonds take precedence over the claims of those who own preferred and common stock. If interest rates rise, the fixed dividend on preferred stocks may be less attractive, causing the price of preferred stocks to decline.
 
Foreign Securities Risk: Investing in foreign securities poses additional risks since political and economic events unique in a country or region will affect those markets and their issuers, while such events may not necessarily affect the U.S. economy or issuers located in the United States. In addition, investments in foreign securities are generally denominated in foreign currency. As a result, changes in the value of those currencies compared to the U.S. dollar may affect (positively or negatively) the value of the Fund's investments. There are also risks associated with foreign accounting standards, government regulation, market information, and clearance and settlement procedures. Foreign markets may be less liquid and more volatile than U.S. markets and offer less protection to investors.

•
Depositary Receipts Risk: Foreign receipts, which include ADRs, Global Depositary Receipts, and European Depositary Receipts, are securities that evidence ownership interests in a security or a pool of securities issued by a foreign issuer. The risks of depositary receipts include many risks associated with investing directly in foreign securities.
 
Management Risk: In managing the Fund’s portfolio, the Advisor engages one or more sub-advisors to make investment decisions for a portion of or the entire portfolio. There is a risk that the Advisor may be unable to identify and retain sub-advisors who achieve superior investment returns relative to other similar sub-advisors.
 
Sector Focus Risk: A fund that focuses its investments in the securities of a particular market sector is subject to the risk that adverse circumstances will have a greater impact on the fund than a fund that does not focus its investments in a particular sector.

Value Investing Risk: Value investing presents the risk that the Fund’s security holdings may never reach their full market value because the market fails to recognize what the portfolio managers consider the true business value or because the portfolio managers have misjudged those values.

As with any mutual fund, there is no guarantee that the Fund will achieve its investment goal. You can find more information about the Fund’s investments and risks under the “Principal Investment Strategies and Risks” section of the Fund’s prospectus.
Risk Lose Money [Text] rr_RiskLoseMoney The Fund’s share price will fluctuate. You could lose money on your investment in the Fund, and the Fund could also return less than other investments. The Fund is subject to the principal risks listed below.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading The Fund’s Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
The bar chart and performance table below illustrate some indication of the risks and volatility of an investment in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and by showing how the Fund’s average annual total returns for one year, five years, and ten years compare with the Russell 1000® Value Index. The bar chart does not reflect any sales charges, which would reduce your return. The performance table does reflect any applicable sales charges. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. More recent performance information is available at no cost by visiting TouchstoneInvestments.com or by calling 1.800.543.0407.
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone 1.800.543.0407
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress TouchstoneInvestments.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading Touchstone Value Fund — Class A Shares Total Return as of December 31
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock
Best Quarter: Second Quarter 2009 17.93%
 
Worst Quarter: Fourth Quarter 2008 (19.65)%
 
The return of the Fund’s Class A shares for the nine months ended September 30, 2017 was 7.74%.
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2017
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 7.74%
Performance Table Heading rr_PerformanceTableHeading Average Annual Total Returns (for the periods ended December 31, 2015)
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Your after-tax returns may differ from those shown and depend on your tax situation.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred The after-tax returns do not apply to shares held in an IRA, 401(k), or other tax-advantaged account.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock
Before the Fund commenced operations, all of the assets and liabilities of the Old Mutual Barrow Hanley Value Fund (the “Predecessor Fund”) were transferred to the Fund in a tax-free reorganization (the “Reorganization”).  The Reorganization occurred on April 16, 2012. As a result of the Reorganization, the Fund assumed the performance and accounting history of the Predecessor Fund prior to the date of the Reorganization. For more information on the prior history of the Fund, please see the section entitled “The Trust” in the Fund’s SAI.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Your after-tax returns may differ from those shown and depend on your tax situation. The after-tax returns do not apply to shares held in an IRA, 401(k), or other tax-advantaged account. After-tax returns are only shown for Class A shares and after-tax returns for other classes will vary.
 
The inception dates of Class A shares, Class C shares, Class Y shares, and Institutional Class shares were: July 31, 2003, April 12, 2012, September 10, 1998 and December 20, 2006, respectively. Class C and Institutional Class shares’ performance was calculated using the historical performance of Class Y shares for the periods prior to April 12, 2012 and December 20, 2006, respectively. Performance for these periods has been restated to reflect the impact of the fees and expenses applicable to Class C and Institutional Class shares.
TOUCHSTONE STRATEGIC TRUST | Touchstone Value Fund | Russell 1000®Value Index  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Russell 1000®Value Index (reflects no deduction for fees, expenses or taxes)
1 Year rr_AverageAnnualReturnYear01 17.34%
5 Years rr_AverageAnnualReturnYear05 14.80%
10 Years rr_AverageAnnualReturnYear10 5.72%
TOUCHSTONE STRATEGIC TRUST | Touchstone Value Fund | Touchstone Value Fund, Class A  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TVLAX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.65%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.34%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 1.24%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.16%)
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.08%
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2018
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 679
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 931
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 1,202
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 1,975
Annual Return 2007 rr_AnnualReturn2007 1.16%
Annual Return 2008 rr_AnnualReturn2008 (36.54%)
Annual Return 2009 rr_AnnualReturn2009 26.28%
Annual Return 2010 rr_AnnualReturn2010 9.79%
Annual Return 2011 rr_AnnualReturn2011 4.21%
Annual Return 2012 rr_AnnualReturn2012 15.15%
Annual Return 2013 rr_AnnualReturn2013 30.93%
Annual Return 2014 rr_AnnualReturn2014 11.07%
Annual Return 2015 rr_AnnualReturn2015 (2.29%)
Annual Return 2016 rr_AnnualReturn2016 13.08%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter:
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Jun. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 17.93%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter:
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (19.65%)
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 6.57%
5 Years rr_AverageAnnualReturnYear05 11.77%
10 Years rr_AverageAnnualReturnYear10 4.93%
TOUCHSTONE STRATEGIC TRUST | Touchstone Value Fund | Touchstone Value Fund, Class A | After Taxes on Distributions  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Taxes on Distributions
1 Year rr_AverageAnnualReturnYear01 6.01%
5 Years rr_AverageAnnualReturnYear05 10.56%
10 Years rr_AverageAnnualReturnYear10 3.77%
TOUCHSTONE STRATEGIC TRUST | Touchstone Value Fund | Touchstone Value Fund, Class A | After Taxes on Distributions and Sales  
Prospectus: rr_ProspectusTable  
Label rr_AverageAnnualReturnLabel Return After Taxes on Distributions and Sale of Fund Shares
1 Year rr_AverageAnnualReturnYear01 4.14%
5 Years rr_AverageAnnualReturnYear05 9.12%
10 Years rr_AverageAnnualReturnYear10 3.57%
TOUCHSTONE STRATEGIC TRUST | Touchstone Value Fund | Touchstone Value Fund, Class C  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TVLCX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.65%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.47%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 2.12%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.29%)
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 1.83%
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 286
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 636
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 1,112
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 2,429
Expense Example, No Redemption, 1 Year rr_ExpenseExampleNoRedemptionYear01 186
Expense Example, No Redemption, 3 Years rr_ExpenseExampleNoRedemptionYear03 636
Expense Example, No Redemption, 5 Years rr_ExpenseExampleNoRedemptionYear05 1,112
Expense Example, No Redemption, 10 Years rr_ExpenseExampleNoRedemptionYear10 $ 2,429
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 11.20%
5 Years rr_AverageAnnualReturnYear05 12.56%
10 Years rr_AverageAnnualReturnYear10 4.91%
TOUCHSTONE STRATEGIC TRUST | Touchstone Value Fund | Touchstone Value Fund, Institutional  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TVLIX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.65%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.21%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 0.86%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.18%)
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 0.68%
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 69
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 256
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 459
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 1,044
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 13.53%
5 Years rr_AverageAnnualReturnYear05 13.51%
10 Years rr_AverageAnnualReturnYear10 5.94%
TOUCHSTONE STRATEGIC TRUST | Touchstone Value Fund | Touchstone Value Fund, Class Y  
Prospectus: rr_ProspectusTable  
Trading Symbol dei_TradingSymbol TVLYX
Maximum Cumulative Sales Charge (as a percentage of Offering Price) rr_MaximumCumulativeSalesChargeOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Redemption Fee rr_RedemptionFee $ (15)
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.65%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.32%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 0.97%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.14%)
Net Expenses (as a percentage of Assets) rr_NetExpensesOverAssets 0.83%
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination October 29, 2017
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 85
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 295
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 523
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 1,177
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 13.32%
5 Years rr_AverageAnnualReturnYear05 13.36%
10 Years rr_AverageAnnualReturnYear10 5.81%
[1] Touchstone Advisors, Inc. (the “Advisor” or “Touchstone Advisors”) and Touchstone Strategic Trust (the “Trust”) have entered into a contractual expense limitation agreement whereby Touchstone Advisors will waive a portion of its fees or reimburse certain Fund expenses (excluding dividend and interest expenses relating to short sales; interest; taxes; brokerage commissions and other transaction costs; portfolio transaction and investment related expenses, including expenses associated with the Fund's liquidity provider; other expenditures which are capitalized in accordance with U.S. generally accepted accounting principles; the cost of “Acquired Fund Fees and Expenses,” if any; and other extraordinary expenses not incurred in the ordinary course of business) in order to limit annual Fund operating expenses to 1.41%, 2.16%, 1.16%, and 1.06% of average daily net assets for Classes A, C, Y and Institutional Class shares, respectively. This contractual expense limitation is effective through October 29, 2018, but can be terminated by a vote of the Board of Trustees of the Trust (the “Board”) if it deems the termination to be beneficial to the Fund’s shareholders. The terms of the contractual expense limitation agreement provide that Touchstone Advisors is entitled to recoup, subject to approval by the Board, such amounts waived or reimbursed for a period of up to three years from the date on which Touchstone Advisors reduced its compensation or assumed expenses for the Fund. The Fund will make repayments to the Advisor only if such repayment does not cause the annual Fund operating expenses (after the repayment is taken into account) to exceed both (1) the expense cap in place when such amounts were waived and (2) the Fund’s current expense limitation.
[2] Total Annual Fund Operating Expenses have been restated to reflect Acquired Fund Fees and Expenses and will differ from the ratio of expenses to average net assets that is included in the Fund's annual report for the fiscal year ended June 30, 2017.
[3] Touchstone Advisors, Inc. (the “Advisor” or “Touchstone Advisors”) and Touchstone Strategic Trust (the “Trust”) have entered into a contractual expense limitation agreement whereby Touchstone Advisors will waive a portion of its fees or reimburse certain Fund expenses (excluding dividend and interest expenses relating to short sales; interest; taxes; brokerage commissions and other transaction costs; portfolio transaction and investment related expenses, including expenses associated with the Fund's liquidity provider; other expenditures which are capitalized in accordance with U.S. generally accepted accounting principles; the cost of “Acquired Fund Fees and Expenses,” if any; and other extraordinary expenses not incurred in the ordinary course of business) in order to limit annual Fund operating expenses to 1.55%, 2.30%, 1.30%, and 1.18% of average daily net assets for Classes A, C, Y, and Institutional Class shares, respectively. This contractual expense limitation is effective through October 29, 2018, but can be terminated by a vote of the Board of Trustees of the Trust (the “Board”) if it deems the termination to be beneficial to the Fund’s shareholders. The terms of the contractual expense limitation agreement provide that Touchstone Advisors is entitled to recoup, subject to approval by the Board, such amounts waived or reimbursed for a period of up to three years from the date on which Touchstone Advisors reduced its compensation or assumed expenses for the Fund. The Fund will make repayments to the Advisor only if such repayment does not cause the annual Fund operating expenses (after the repayment is taken into account) to exceed both (1) the expense cap in place when such amounts were waived and (2) the Fund’s current expense limitation.
[4] Touchstone Advisors, Inc. (the “Advisor” or “Touchstone Advisors”) and Touchstone Strategic Trust (the “Trust”) have entered into a contractual expense limitation agreement whereby Touchstone Advisors will waive a portion of its fees or reimburse certain Fund expenses (excluding dividend and interest expenses relating to short sales; interest; taxes; brokerage commissions and other transaction costs; portfolio transaction and investment related expenses, including expenses associated with the Fund's liquidity provider; other expenditures which are capitalized in accordance with U.S. generally accepted accounting principles; the cost of “Acquired Fund Fees and Expenses,” if any; and other extraordinary expenses not incurred in the ordinary course of business) in order to limit annual Fund operating expenses to 1.12%, 1.87%, 0.87%, and 0.77% of average daily net assets for Classes A, C, Y, and Institutional Class shares, respectively. This contractual expense limitation is effective through October 29, 2018, but can be terminated by a vote of the Board of Trustees of the Trust (the “Board”) if it deems the termination to be beneficial to the Fund’s shareholders. The terms of the contractual expense limitation agreement provide that Touchstone Advisors is entitled to recoup, subject to approval by the Board, such amounts waived or reimbursed for a period of up to three years from the date on which Touchstone Advisors reduced its compensation or assumed expenses for the Fund. The Fund will make repayments to the Advisor only if such repayment does not cause the annual Fund operating expenses (after the repayment is taken into account) to exceed both (1) the expense cap in place when such amounts were waived and (2) the Fund’s current expense limitation.
[5] Touchstone Advisors, Inc. (the “Advisor” or “Touchstone Advisors”) and the Touchstone Strategic Trust (the "Trust") have entered into a contractual expense limitation agreement whereby Touchstone Advisors will waive a portion of its fees or reimburse certain Fund expenses (excluding dividend and interest expenses relating to short sales; interest; taxes; brokerage commissions and other transaction costs; portfolio transaction and investment related expenses, including expenses associated with the Fund's liquidity provider; other expenditures which are capitalized in accordance with U.S. generally accepted accounting principles; the cost of “Acquired Fund Fees and Expenses,” if any; and other extraordinary expenses not incurred in the ordinary course of business) in order to limit annual Fund operating expenses to 1.23%, 1.98%, 0.98%, and 0.88% of average daily net assets for Classes A, C, Y and Institutional Class shares, respectively. This contractual expense limitation is effective through October 29, 2018, but can be terminated by a vote of the Board of Trustees of the Trust (the “Board”) if it deems the termination to be beneficial to the Fund’s shareholders. The terms of the contractual expense limitation agreement provide that Touchstone Advisors is entitled to recoup, subject to approval by the Board, such amounts waived or reimbursed for a period of up to three years from the date on which Touchstone Advisors reduced its compensation or assumed expenses for the Fund. The Fund will make repayments to the Advisor only if such repayment does not cause the annual Fund operating expenses (after the repayment is taken into account) to exceed both (1) the expense cap in place when such amounts were waived and (2) the Fund’s current expense limitation.
[6] Total Annual Fund Operating Expenses After Fee Waiver or Expense Reimbursement differ from the ratio of net expenses to average net assets shown in the annual report for the fiscal year ended June 30, 2017 due to a contractual change in the expense limitation agreement.
[7] Touchstone Advisors, Inc. (the “Advisor” or “Touchstone Advisors”) and Touchstone Strategic Trust (the “Trust”) have entered into a contractual expense limitation agreement whereby Touchstone Advisors will waive a portion of its fees or reimburse certain Fund expenses (excluding dividend and interest expenses relating to short sales; interest; taxes; brokerage commissions and other transaction costs; portfolio transaction and investment related expenses, including expenses associated with the Fund's liquidity provider; other expenditures which are capitalized in accordance with U.S. generally accepted accounting principles, the cost of “Acquired Fund Fees and Expenses,” if any; and other extraordinary expenses not incurred in the ordinary course of business) in order to limit annual fund operating expenses to 0.85%, 1.60%, 0.60% and 0.55% of average daily net assets for Classes A, C, Y and Institutional Class shares, respectively. This contractual expense limitation is effective through October 29, 2018, but can be terminated by a vote of the Board of Trustees of the Trust (the “Board”) if it deems the termination to be beneficial to the Fund’s shareholders. The terms of the contractual expense limitation agreement provide that Touchstone Advisors is entitled to recoup, subject to approval by the Board, such amounts waived or reimbursed for a period of up to three years from the date on which Touchstone Advisors reduced its compensation or assumed expenses for the Fund. The Fund will make repayments to the Advisor only if such repayment does not cause the annual Fund operating expenses (after the repayment is taken into account) to exceed both (1) the expense cap in place when such amounts were waived and (2) the Fund’s current expense limitation.
[8] Touchstone Advisors, Inc. (the “Advisor” or “Touchstone Advisors”) and Touchstone Strategic Trust (the “Trust”) have entered into a contractual expense limitation agreement whereby Touchstone Advisors will waive a portion of its fees or reimburse certain Fund expenses (excluding dividend and interest expenses relating to short sales; interest; taxes; brokerage commissions and other transaction costs; portfolio transaction and investment related expenses, including expenses associated with the Fund's liquidity provider; other expenditures which are capitalized in accordance with U.S. generally accepted accounting principles; the cost of “Acquired Fund Fees and Expenses,” if any; and other extraordinary expenses not incurred in the ordinary course of business) in order to limit annual Fund operating expenses to 1.43%, 2.18%, 1.18%, and 1.10% of average daily net assets for Classes A, C, Y, and Institutional Class shares, respectively. This contractual expense limitation is effective through October 29, 2018, but can be terminated by a vote of the Board of Trustees of the Trust (the “Board”) if it deems the termination to be beneficial to the Fund’s shareholders. The terms of the contractual expense limitation agreement provide that Touchstone Advisors is entitled to recoup, subject to approval by the Board, such amounts waived or reimbursed for a period of up to three years from the date on which Touchstone Advisors reduced its compensation or assumed expenses for the Fund. The Fund will make repayments to the Advisor only if such repayment does not cause the annual Fund operating expenses (after the repayment is taken into account) to exceed both (1) the expense cap in place when such amounts were waived and (2) the Fund’s current expense limitation.