Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	RS INVESTMENT TRUST
Prospectus Date	rr_ProspectusDate	May 01, 2013
Class Y Prospectus | RS International Growth Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	RS International Growth Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	Long-term capital appreciation.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses of the Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund. No sales loads are imposed on Class Y shares.
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, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes 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 21% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	21.00%
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 costs of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated, whether or not you redeem at the end of such periods. 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:
Strategy [Heading]	rr_StrategyHeading	Investments, Risks, and Performance Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund normally invests at least 80% of the value of the Fund’s net assets in common stocks and convertible securities issued by (i) companies organized, domiciled, or with a principal office outside of the United States, (ii) companies which primarily trade in a market located outside of the United States, or (iii) companies which do a substantial amount of business outside of the United States, which the investment team considers to be companies that derive at least 50% of their revenue or profits from business outside the United States or have at least 50% of their sales or assets outside the United States. The Fund does not usually focus its investments in a particular industry or country. A significant part of the Fund’s assets will normally be divided among continental Europe, the United Kingdom, Japan, and Asia (including Australia and New Zealand). However, there are no limitations on how much money the Fund can invest in any one country. The Fund may invest up to 20% (measured at the time of purchase) of its total assets in countries in emerging markets when the Fund’s investment team believes it would be appropriate to do so. The Fund’s investment team uses fundamental research and a bottom-up approach to country and asset allocation, with the objective of making long-term investments in companies it believes can sustain above-average growth rates and that currently trade at prices that do not fully reflect those rates of growth. The investment team looks for companies that it believes have strong competitive positions within attractive industries, high-quality earnings, and a positive approach toward shareholders. Some of the fundamental factors that the team considers when analyzing companies are: earnings growth, cash flow growth, profitability, debt and interest cover, and valuation. To determine how to allocate the Fund’s assets geographically, the Fund’s investment team evaluates economic, market, and political trends worldwide. Among the factors considered are currency exchange rates, the growth potential of economies and securities markets, technological developments, and political and social conditions. The Fund also may invest in foreign issuers through American Depositary Receipts (ADRs), European Depositary Receipts (EDRs), Global Depositary Receipts (GDRs), or similar investment vehicles.
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. Equity Securities Risk The value of a company’s stock may decline in response to factors affecting that particular company or stock markets generally. 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. 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. Small Companies Risk Small companies may be subject to a number of risks not associated with larger, more established companies, potentially making their stock prices more volatile and increasing the risk of loss. Emerging Market Risk Risks of investing in emerging markets include greater political and economic instability, greater volatility in currency exchange rates, less developed securities markets, possible trade barriers, currency transfer restrictions, a more limited number of potential buyers, an emerging market country’s dependence on revenue from particular commodities or international aid, less governmental supervision and regulation, unavailability of currency hedging techniques, differences in auditing and financial reporting standards, and less developed legal systems. Investment Style Risk A mutual fund investing principally in growth style stocks may at times underperform other mutual funds that invest more broadly or that have different investment styles. 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 Baillie Gifford Overseas Limited, 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. Cash Position Risk To the extent that the Fund holds assets in cash and cash equivalents and not in the investments previously described, the ability of the Fund to meet its objective may be limited. Overweighting Risk Overweighting investments in an industry or group of industries relative to the Fund’s benchmark increases the risk that the Fund will underperform its benchmark because a general decline in the prices of stocks in that industry or group of industries will affect the Fund to a greater extent than its benchmark. Underweighting Risk If the Fund underweights its investment in an industry or group of industries relative to the Fund’s benchmark, the Fund will participate in any general increase in the value of companies in that industry or group of industries to a lesser extent than the Fund’s benchmark.
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, 5, and 10 years and since inception compare with those of a broad measure of market performance. 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, 5, and 10 years 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 Y Shares (calendar year-end)
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Best Quarter  Second Quarter 2009  23.52%    Worst Quarter  Fourth Quarter 2008  -23.14%
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 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. 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. The Fund commenced investment operations February 16, 1993, with the offering of Class A shares, and subsequently offered Class Y shares on March 9, 2009. Performance shown for Class Y shares reflects the performance of the Fund’s Class A shares for periods through the Class Y shares’ inception on March 10, 2009. Blended class performance has been adjusted to take into account differences in sales load applicable to these share classes (Class A shares charge a sales load and Class Y shares do not charge a sales load), but has not been adjusted to take into account differences in class-specific operating expenses (such as Rule 12b-1 fees; Class A shares pay a 12b-1 fee of 0.25% and Class Y shares do not pay a 12b-1 fee). Because Class Y shares’ operating expenses are lower than Class A shares’ historical operating expenses, historical performance of Class A shares is likely lower than what the performance of Class Y shares would have been during that period.
Class Y Prospectus | RS International Growth Fund | Class Y
Risk/Return:	rr_RiskReturnAbstract
Management Fee	rr_ManagementFeesOverAssets	0.80%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets
Other Expenses	rr_OtherExpensesOverAssets	0.22%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.02%	[1]
Fee Waiver/Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[1]
Total Annual Fund Operating Expenses After Fee Waiver/Expense Reimbursement	rr_NetExpensesOverAssets	1.02%	[1]
1 Year	rr_ExpenseExampleYear01	104
3 Years	rr_ExpenseExampleYear03	325
5 Years	rr_ExpenseExampleYear05	563
10 Years	rr_ExpenseExampleYear10	1,248
1 Year	rr_ExpenseExampleNoRedemptionYear01	104
3 Years	rr_ExpenseExampleNoRedemptionYear03	325
5 Years	rr_ExpenseExampleNoRedemptionYear05	563
10 Years	rr_ExpenseExampleNoRedemptionYear10	1,248
2003	rr_AnnualReturn2003	28.57%	[2]
2004	rr_AnnualReturn2004	16.34%	[2]
2005	rr_AnnualReturn2005	15.63%	[2]
2006	rr_AnnualReturn2006	22.44%	[2]
2007	rr_AnnualReturn2007	14.17%	[2]
2008	rr_AnnualReturn2008	(43.23%)	[2]
2009	rr_AnnualReturn2009	36.67%	[2]
2010	rr_AnnualReturn2010	14.93%
2011	rr_AnnualReturn2011	(12.90%)
2012	rr_AnnualReturn2012	18.00%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best Quarter
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	23.52%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst Quarter
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(23.14%)
1 Year	rr_AverageAnnualReturnYear01	18.00%
5 Years	rr_AverageAnnualReturnYear05	(1.73%)	[2]
10 Years	rr_AverageAnnualReturnYear10	8.28%	[2]
Since Inception	rr_AverageAnnualReturnSinceInception	5.92%	[2]
Inception Date	rr_AverageAnnualReturnInceptionDate	Feb. 16, 1993
Class Y Prospectus | RS International Growth Fund | Return After Taxes on Distributions | Class Y
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	17.65%
5 Years	rr_AverageAnnualReturnYear05	(2.07%)	[2]
10 Years	rr_AverageAnnualReturnYear10	7.95%	[2]
Since Inception	rr_AverageAnnualReturnSinceInception	5.15%	[2]
Inception Date	rr_AverageAnnualReturnInceptionDate	Feb. 16, 1993
Class Y Prospectus | RS International Growth Fund | Return After Taxes on Distributions and Sale of Fund Shares | Class Y
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	11.70%
5 Years	rr_AverageAnnualReturnYear05	(1.67%)	[2]
10 Years	rr_AverageAnnualReturnYear10	7.14%	[2]
Since Inception	rr_AverageAnnualReturnSinceInception	4.90%	[2]
Inception Date	rr_AverageAnnualReturnInceptionDate	Feb. 16, 1993
Class Y Prospectus | RS International Growth Fund | MSCI EAFE Index (Gross) (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	17.90%
5 Years	rr_AverageAnnualReturnYear05	(3.21%)	[2]
10 Years	rr_AverageAnnualReturnYear10	8.70%	[2]
Since Inception	rr_AverageAnnualReturnSinceInception	6.50%	[2],[3]
Inception Date	rr_AverageAnnualReturnInceptionDate	Jan. 31, 1993

[1] 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) to 1.15% for Class Y shares. 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.

[2] Returns for the periods through March 10, 2009 reflect performance for the Fund's Class A shares. Class A shares represent an investment in the same portfolio of securities as Class Y shares. Annual returns for Class A and Class Y shares differ to the extent Class Y shares do not have the same expenses as Class A shares.

[3] Since inception returns for MSCI EAFE Index (Gross) shown in the table are since January 31, 1993, the month end prior to the inception of Class A shares.