Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	RS INVESTMENT TRUST
Prospectus Date	rr_ProspectusDate	May 01, 2013
Retail Class Prospectus | RS Floating Rate Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	RS Floating Rate Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	To seek a high level of current income.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses of the Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The tables below describe 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 the purchase of Class A shares if you and your family invest, or agree to invest in the future, at least $100,000 in RS Funds. More information about these and other discounts is available from your financial professional and in the “Types of Shares Available — Class A Shares” section on page 110 of the Fund’s prospectus and the “Waivers of Certain Sales Loads” section on page 37 of the Fund’s statement of additional information.
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 are deducted from Fund assets as a percentage of average daily net assets)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	April 30, 2014
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs 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 for you if your 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 52% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	52.00%
Expense Breakpoint Discounts [Text]	rr_ExpenseBreakpointDiscounts	You may qualify for sales charge discounts for the purchase of Class A shares if you and your family invest, or agree to invest in the future, at least $100,000 in RS Funds.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	100,000
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 costs of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated. This Example also assumes that your investment earns a 5% return each year and that the Fund’s operating expenses remain the same as shown above. 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	Investments, Risks, and Performance Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund invests primarily in floating rate loans and other floating rate investments. The investment team expects that most or all of the investments held by the Fund will typically be below investment grade. Floating rate investments are debt obligations of companies or other entities that have interest rates that adjust or “float” periodically, normally on a daily, monthly, quarterly, or semiannual basis by reference to a base lending rate (such as LIBOR) plus a premium. A floating rate loan is typically structured and administered by a financial institution that acts as the agent of the lenders participating in the floating rate loan. The Fund will typically acquire loans directly in a transaction arranged through an agent or by assignment from another holder of the loan. The Fund will typically invest in senior secured corporate loans. The Fund’s investment team considers several factors in purchasing and selling investments for the Fund, such as fundamental analysis of the issuer, the credit quality of the issuer and any collateral securing the investment, the issuer’s management, capital structure, leverage, and operational performance, and the business outlook for the industry of the issuer. The Fund normally invests at least 80% of its net assets in floating rate loans and other floating rate investments. Floating rate investments include, without limitation, floating rate debt securities, money market securities of all types, repurchase agreements, and shares of money market funds. For this purpose, the investment team considers floating rate investments to include investments whose interest rates do not by their terms reset prior to maturity but have maturities of six months or less. The Fund may invest up to 100% of its assets in obligations of foreign issuers, including sovereign and private issuers. The Fund may enter into foreign currency exchange transactions in order to hedge against adverse changes in the values of currencies in which those obligations are denominated. Floating rate loans in which the Fund invests are expected to be “senior” loans, although the Fund may invest in other types of loans. Senior floating rate loans typically hold a senior position in the capital structure of the borrower, are typically secured by specific collateral, and have a claim on the assets and/or stock of the borrower that is senior to that held by subordinated debtholders and stockholders of the borrower. While these protections may reduce risk, these investments still present significant credit risk. For example, the Fund may be delayed or prevented from realizing on its collateral. A significant portion of the Fund’s floating rate investments may be issued in connection with highly leveraged transactions such as leveraged buyouts, leveraged recapitalization loans, and other types of acquisition financing. Obligations in these types of transactions are subject to greater credit risk (including default and bankruptcy) than many other investments. The Fund may purchase second lien loans (secured loans with a claim on collateral subordinate to a senior lender’s claim on such collateral), fixed rate loans, unsecured loans, and other debt obligations. Other debt obligations in which the Fund may invest include all types of debt instruments such as corporate bonds, government securities, repurchase agreements, and mortgage and other asset-backed securities. An investment will be considered to be below investment grade if it is rated Ba1 by Moody’s Investors Service, Inc. and BB+ by Standard & Poor’s Ratings Group, or lower or, if unrated, is considered by the Fund’s investment team to be of comparable quality. A below investment grade rating reflects a greater possibility that the issuer of an investment may be unable to make timely payments of interest and principal and thus default. If this happens, or is perceived as likely to happen, the value of that investment will usually be more volatile and is likely to fall. A default or expected default would likely also make it difficult for the Fund to sell an investment at a price approximating the value the Fund has previously placed on it. Senior loans typically are of below investment grade quality and (if rated) have below investment grade credit ratings, which ratings are associated with securities having high risk, speculative characteristics (sometimes referred to as “junk”). Credit ratings are based largely on the issuer’s historical financial condition and the rating agencies’ investment analysis at the time of rating. The rating assigned to any particular investment does not necessarily reflect the issuer’s current financial condition, and does not reflect an assessment of an investment’s volatility or liquidity. Although the Fund’s investment team considers credit ratings in making investment decisions, it performs its own investment analysis and does not rely only on ratings assigned by the rating agencies. The Fund depends more on the Fund’s investment team’s ability to buy lower-rated debt than it does on its ability to buy investment-grade debt. The Fund may have to participate in legal proceedings or take possession of and manage assets that secure the issuer’s obligations. This could increase the Fund’s operating expenses and decrease its net asset value. The Fund’s investment team may seek to avoid the receipt of material non-public information about the issuers of floating rate loans being considered for purchase by the Fund, which may affect its ability to assess the floating rate loans as compared to investors that do receive such information. The Fund may enter into exchange-traded or over-the-counter derivatives transactions of any kind, such as futures contracts, options on futures, and swap contracts, including, for example, interest rate swaps and credit default swaps. The Fund also may enter into exchange-traded or over-the-counter foreign currency exchange transactions, including currency futures, forward, and option transactions. The Fund may enter into any of these transactions for a variety of purposes, including, but not limited to, hedging various risks such as credit risk, interest rate risk, currency risk, and liquidity risk; taking a net long or short position in certain investments or markets; providing liquidity in the Fund; equitizing cash; minimizing transaction costs; generating income; adjusting the Fund’s sensitivity to interest rate risk, currency risk, or other risk; replicating certain direct investments; and asset and sector allocation.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	You may lose money by investing in the Fund. The Fund may not achieve its investment objective. The principal risks of investing in the Fund, which could adversely affect its net asset value and total return, are as follows. Debt Securities Risk The value of a debt security or other income-producing security changes in response to various factors, including, by way of example, market-related factors (such as changes in interest rates or changes in the risk appetite of investors generally) and changes in the actual or perceived ability of the issuer (or of issuers generally) to meet its (or their) obligations. Securities with floating interest rates generally are less sensitive to interest rate changes, but may decline in value if their interest rates do not rise as much as interest rates in general. High-yield/Junk Bond Risk Lower-quality debt securities can involve a substantially greater risk of default than higher quality debt securities, and their values can decline significantly over short periods of time. Lower-quality debt securities tend to be more sensitive to adverse news about the issuer, or the market or economy in general. Liquidity Risk Lack of a ready market or restrictions on resale may limit the ability of the Fund to sell a security at an advantageous time or price. In addition, the Fund, by itself or together with other accounts managed by Guardian Investor Services LLC, may hold a position in a security that is large relative to the typical trading volume for that security, which can make it difficult for the Fund to dispose of the position at an advantageous time or price. Loan Risk Investments in loans are generally subject to the same risks as investments in other types of debt securities, including, in many cases, investments in high-yield/junk bonds. They may be difficult to value and may be illiquid. If the Fund holds a loan through another financial institution, or relies on a financial institution to administer the loan, its receipt of principal and interest on the loan may be subject to the credit risk of that financial institution. It is possible that any collateral securing a loan may be insufficient or unavailable to the Fund, and that the Fund’s rights to collateral may be limited by bankruptcy or insolvency laws. There may be limited public information available regarding the loan. Transactions in loans may settle on a delayed basis, and the Fund may not receive the proceeds from the sale of a loan for a substantial period of time after the sale. Foreign Securities Risk Foreign securities are subject to political, regulatory, and economic risks not present in domestic investments. In addition, when the Fund buys securities denominated in a foreign currency, there are special risks such as changes in currency exchange rates and the risk that a foreign government could regulate foreign exchange transactions. In addition, to the extent that investments are made in a limited number of countries, events in those countries will have a more significant impact on the Fund. Derivatives Risk Derivative transactions can create investment leverage and may be highly volatile. It is possible that a derivative transaction will result in a loss greater than the principal amount invested, and the Fund may not be able to close out a derivative transaction at a favorable time or price. The counterparty to a derivatives contract may be unable or unwilling to make timely settlement payments, return the Fund’s margin, or otherwise honor its obligations. Currency Risk Investments in foreign securities are often denominated and traded in foreign currencies. The value of the Fund’s assets may be affected favorably or unfavorably by currency exchange rates, currency exchange control regulations, and restrictions or prohibitions on the repatriation of foreign currencies. To attempt to protect against changes in currency exchange rates, the Fund may, but will not necessarily, engage in forward foreign-currency exchange transactions. The use of foreign exchange transactions to reduce foreign-currency exposure can eliminate some or all of the benefit of an increase in the value of a foreign currency versus the U.S. dollar. Credit Derivatives Risk The Fund may enter into credit derivatives, including credit default swaps and credit default index investments. The Fund may use these investments (i) as alternatives to direct long or short investment in a particular security, (ii) to adjust the Fund’s asset allocation or risk exposure, or (iii) for hedging purposes. The use by the Fund of credit default swaps may have the effect of creating a short position in a security. These investments can create investment leverage and may create additional investment risks that may subject the Fund to greater volatility than investments in more traditional securities.
Risk Lose Money [Text]	rr_RiskLoseMoney	You may lose money by investing in the Fund.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Fund Performance
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and table provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and by showing how the Fund’s average annual returns for 1 year and since inception compare with those of a broad measure of market performance. The returns in the bar chart do not reflect the impact of sales loads. If they did, the returns would be lower than those shown. The Fund’s past performance (before and after taxes) is not an indication of future performance. Updated performance information for the Fund is available at www.rsinvestments.com or by calling 800-766-3863.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and table provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and by showing how the Fund’s average annual returns for 1 year and since inception compare with those of a broad measure of market performance.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	800-766-3863
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.rsinvestments.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The Fund’s past performance (before and after taxes) is not an indication of future performance.
Bar Chart [Heading]	rr_BarChartHeading	Annual Total Return for Class A Shares (calendar year-end)
Bar Chart Does Not Reflect Sales Loads [Text]	rr_BarChartDoesNotReflectSalesLoads	The returns in the bar chart do not reflect the impact of sales loads. If they did, the returns would be lower than those shown.
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Best Quarter  First Quarter 2012  4.22% Worst Quarter  Third Quarter 2011  -4.49%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (periods ended 12/31/12)
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	Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns are shown for Class A shares only; after-tax returns for other classes will vary.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	After-tax returns are shown for Class A shares only; after-tax returns for other classes will vary. 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. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
Retail Class Prospectus | RS Floating Rate Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	2.25%
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of sale proceeds or the original offering price)	rr_MaximumDeferredSalesChargeOverOfferingPrice	none	[1]
Management Fees	rr_ManagementFeesOverAssets	0.65%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	0.15%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.05%	[2]
Fee Waiver/Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.07%)	[2]
Total Annual Fund Operating Expenses After Fee Waiver/Expense Reimbursement	rr_NetExpensesOverAssets	0.98%	[2]
Expenses Deferred Charges [Text Block]	rr_ExpensesDeferredChargesTextBlock	Contingent deferred sales load of 1.00% applies to purchases of $1 million or more of Class A shares if these shares are sold within 18 months of purchase.
1 Year	rr_ExpenseExampleYear01	323
3 Years	rr_ExpenseExampleYear03	545
5 Years	rr_ExpenseExampleYear05	785
10 Years	rr_ExpenseExampleYear10	1,473
1 Year	rr_ExpenseExampleNoRedemptionYear01	323
3 Years	rr_ExpenseExampleNoRedemptionYear03	545
5 Years	rr_ExpenseExampleNoRedemptionYear05	785
10 Years	rr_ExpenseExampleNoRedemptionYear10	1,473
2010	rr_AnnualReturn2010	8.37%
2011	rr_AnnualReturn2011	1.02%
2012	rr_AnnualReturn2012	9.96%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best Quarter
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Mar. 31, 2012
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	4.22%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst Quarter
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2011
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(4.49%)
1 Year	rr_AverageAnnualReturnYear01	7.45%
Since Inception	rr_AverageAnnualReturnSinceInception	5.58%
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 31, 2009
Retail Class Prospectus | RS Floating Rate Fund | Class C
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of sale proceeds or the original offering price)	rr_MaximumDeferredSalesChargeOverOfferingPrice	1.00%	[3]
Management Fees	rr_ManagementFeesOverAssets	0.65%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other Expenses	rr_OtherExpensesOverAssets	0.19%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.84%	[2]
Fee Waiver/Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.07%)	[2]
Total Annual Fund Operating Expenses After Fee Waiver/Expense Reimbursement	rr_NetExpensesOverAssets	1.77%	[2]
Expenses Deferred Charges [Text Block]	rr_ExpensesDeferredChargesTextBlock	Contingent deferred sales load applies for shares sold within one year of purchase.
1 Year	rr_ExpenseExampleYear01	280
3 Years	rr_ExpenseExampleYear03	572
5 Years	rr_ExpenseExampleYear05	989
10 Years	rr_ExpenseExampleYear10	2,153
1 Year	rr_ExpenseExampleNoRedemptionYear01	180
3 Years	rr_ExpenseExampleNoRedemptionYear03	572
5 Years	rr_ExpenseExampleNoRedemptionYear05	989
10 Years	rr_ExpenseExampleNoRedemptionYear10	2,153
1 Year	rr_AverageAnnualReturnYear01	7.98%
Since Inception	rr_AverageAnnualReturnSinceInception	5.80%
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 31, 2009
Retail Class Prospectus | RS Floating Rate Fund | Class K
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of sale proceeds or the original offering price)	rr_MaximumDeferredSalesChargeOverOfferingPrice	none
Management Fees	rr_ManagementFeesOverAssets	0.65%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.65%
Other Expenses	rr_OtherExpensesOverAssets	0.22%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.52%	[2]
Fee Waiver/Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.07%)	[2]
Total Annual Fund Operating Expenses After Fee Waiver/Expense Reimbursement	rr_NetExpensesOverAssets	1.45%	[2]
1 Year	rr_ExpenseExampleYear01	148
3 Years	rr_ExpenseExampleYear03	473
5 Years	rr_ExpenseExampleYear05	822
10 Years	rr_ExpenseExampleYear10	1,807
1 Year	rr_ExpenseExampleNoRedemptionYear01	148
3 Years	rr_ExpenseExampleNoRedemptionYear03	473
5 Years	rr_ExpenseExampleNoRedemptionYear05	822
10 Years	rr_ExpenseExampleNoRedemptionYear10	1,807
1 Year	rr_AverageAnnualReturnYear01	9.31%
Since Inception	rr_AverageAnnualReturnSinceInception	5.98%
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 31, 2009
Retail Class Prospectus | RS Floating Rate Fund | Return After Taxes on Distributions | Class A
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	5.47%
Since Inception	rr_AverageAnnualReturnSinceInception	3.61%
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 31, 2009
Retail Class Prospectus | RS Floating Rate Fund | Return After Taxes on Distributions and Sale of Fund Shares | Class A
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	4.80%
Since Inception	rr_AverageAnnualReturnSinceInception	3.59%
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 31, 2009
Retail Class Prospectus | RS Floating Rate Fund | S&P/LSTA U.S. Leveraged Loan Index (reflects no deductions for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	9.66%
Since Inception	rr_AverageAnnualReturnSinceInception	7.03%
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 31, 2009

[1] Contingent deferred sales load of 1.00% applies to purchases of $1 million or more of Class A shares if these shares are sold within 18 months of purchase.

[2] RS Investments has contractually agreed to limit the Total Annual Fund Operating Expenses (excluding expenses indirectly incurred by the Fund through investments in pooled investment vehicles, interest, taxes, investment-related expenses (e.g., brokerage commissions), and extraordinary expenses) for Class A shares to 0.98% and to limit the Total Annual Fund Operating Expenses of each of the other classes of the Fund so that each of those classes benefits from a level of reimbursement (as expressed in basis points) that is the same as the level of reimbursement for Class A shares during the period. This expense limitation will continue through April 30, 2014 and cannot be terminated by RS Investments prior to that date without the action or consent of the Fund's Board of Trustees.

[3] Contingent deferred sales load applies for shares sold within one year of purchase.