Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
ProspectusDate	rr_ProspectusDate	Aug. 01, 2011
Japan 2x Strategy Fund (First Prospectus Summary) | Japan 2x Strategy Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return, Heading	rr_RiskReturnHeading	JAPAN 2x STRATEGY FUND
Risk/Return, Supplement Text Block	ck0000899148_SupplementTextBlock	IMPORTANT INFORMATION ABOUT THE FUND - The Japan 2x Strategy Fund (the "Fund") is very different from most other mutual funds in that it seeks leveraged investment results. As a result, the Fund may be riskier than alternatives that do not use leverage because the performance of an investment is magnified. The effect of leverage on the Fund will generally cause the Fund's performance to not correlate to the performance of the Fund's benchmark (as defined below) over a period of time greater than one day. This means that the return of the Fund for a period of longer than a single trading day will be the result of each day's compounded returns over the period, which will very likely differ from twice the return of the Fund's underlying index (as defined below) for that period. As a consequence, especially in periods of market volatility, the path or trend of the benchmark during the longer period may be at least as important to the Fund's cumulative return for the longer period as the cumulative return of the benchmark for the relevant longer period. Further, the return for investors who invest for a period longer than a single trading day will not be the product of the return of the Fund's stated investment goal (e.g., 2x) and the cumulative performance of the underlying index (as defined below). The Fund is not suitable for all investors. The Fund should be utilized only by investors who (a) understand the risks associated with the use of leverage, (b) understand the consequences of seeking leveraged investment results, and (c) intend to actively monitor and manage their investments. Investors who do not meet these criteria should not buy shares of the Fund. An investment in the Fund is not a complete investment program.
Investment Objective, Heading	rr_ObjectiveHeading	INVESTMENT OBJECTIVE -
investment Objective, Primary	rr_ObjectivePrimaryTextBlock	The Fund seeks to provide investment results that correlate, before fees and expenses, to the performance of a specific benchmark. The Fund's current benchmark is 200% of the fair value of the Nikkei 225 Stock Average (the "underlying index").
Expense, Heading	rr_ExpenseHeading	FEES AND EXPENSES OF THE FUND -
Expense, Narrative	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold H-Class Shares of the Fund.
Shareholder Fees, Caption	rr_ShareholderFeesCaption	SHAREHOLDER FEES (fees paid directly from your investment) N/A
Operating Expenses, Caption	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	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in 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 0% of the average value of its portfolio. However, the Fund's portfolio turnover rate is calculated without regard to cash instruments or derivatives. If such instruments were included, the Fund's portfolio turnover rate might be significantly higher.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	0.00%
Expense Example, Heading	rr_ExpenseExampleHeading	EXAMPLE -
Expense Example, Narrative	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 redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Investment Strategy, Heading	rr_StrategyHeading	PRINCIPAL INVESTMENT STRATEGIES -
Investment Strategy, Narrative	rr_StrategyNarrativeTextBlock	The Fund employs as its investment strategy a program of investing in the common stock of companies that are generally within the capitalization range of the underlying index and derivative instruments, which primarily consist of equity index swaps, futures contracts, and options on securities, futures contracts, and stock indices. Equity index swaps and futures and options contracts, if used properly, may enable the Fund to meet its objective by increasing the Fund's exposure to the securities included in the underlying index or to securities whose performance is highly correlated to that of the underlying index. Under normal circumstances, the Fund will invest at least 80% of its net assets, plus any borrowings for investment purposes, in securities of companies in the underlying index and derivatives and other instruments whose performance is expected to correspond to that of the underlying index. The Nikkei 225 Stock Average is a price-weighted average of 225 top-rated Japanese companies listed on the First Section of the Tokyo Stock Exchange that are selected to be both highly liquid and representative of Japan's industrial structure. As of June 30, 2011, the Nikkei 225 Stock Average included companies with small, medium and large capitalizations ranging from $317.88 million to $128.13 billion. Certain of the Fund's derivative investments may be traded in the over-the-counter ("OTC") market. On a day-to-day basis, the Fund may hold U.S. government securities or cash equivalents to collateralize its derivative positions. The Fund also may invest in American Depositary Receipts ("ADRs") to gain exposure to the underlying index. In an effort to ensure that the Fund is fully invested on a day-to-day basis, the Fund may conduct any necessary trading activity at or just prior to the close of the U.S. financial markets. To the extent the Fund's underlying index is concentrated in a particular industry the Fund will necessarily be concentrated in that industry. The Fund is non-diversified and, therefore, may invest a greater percentage of its assets in a particular issuer in comparison to a diversified fund.
Risk, Heading	rr_RiskHeading	PRINCIPAL RISKS -
Risk, Narrative	rr_RiskNarrativeTextBlock	As with all mutual funds, a shareholder is subject to the risk that his or her investment could lose money. In addition to this risk, the Fund is subject to a number of additional risks that may affect the value of its shares, including: Active Trading Risk - Active trading, also called "high portfolio turnover," may result in higher brokerage costs or mark-up charges, which may negatively affect Fund performance and result in short-term capital gains, which have a negative tax effect. Large movements of assets into and out of the Fund due to active trading also may adversely affect the Fund's ability to achieve its investment objective. Correlation and Compounding Risk - A number of factors may affect the Fund's ability to achieve a high degree of correlation with its benchmark, and there can be no guarantee that the Fund will achieve a high degree of correlation. Failure to achieve a high degree of correlation may prevent the Fund from achieving its investment objective. The risk of the Fund not achieving its investment objective will be more acute when the underlying index has an extreme one-day movement approaching 50%. In addition, as a result of compounding and the times at which the Fund and the underlying index calculate their respective NAVs, the Fund's performance is likely to be either greater than or less than the performance of the underlying index times the stated multiple in the Fund's investment objective, before accounting for fees and fund expenses. Compounding affects all investments, but has a more significant impact on a leveraged index fund. In general, particularly during periods of higher index volatility, compounding will cause longer-term results to be more or less than the return of the Fund's benchmark. This effect becomes more pronounced as volatility increases. Fund performance for periods greater than one day can be estimated given any set of assumptions for the following factors: (a) underlying index performance; (b) underlying index volatility; (c) financing rates associated with leverage; (d) other Fund expenses; (e) dividends paid by companies in the underlying index; and (f) period of time. The chart below illustrates the impact of two principal factors - volatility and index performance - on Fund performance. The chart shows estimated Fund returns for a number of combinations of performance and volatility over a one-year period. Performance shown in the chart assumes: (a) no dividends paid by the companies included in the underlying index; (b) no Fund expenses; and (c) a cost of leverage of zero percent. If Fund expenses were included, the Fund's performance would be lower than shown. Areas shaded lighter represent those scenarios where the Fund can be expected to return more than twice the performance of the underlying index; conversely, areas shaded darker represent those scenarios where the Fund can be expected to return less than twice the performance of the underlying index. Index Performance Annualized Volatility 1x 2x 10% 25% 50% 75% 100% -60% -120% -84% -85% -88% -91% -94% -50% -100% -75% -77% -81% -86% -91% -40% -80% -65% -66% -72% -80% -87% -30% -60% -52% -54% -62% -72% -82% -20% -40% -37% -41% -49% -64% -78% -10% -20% -20% -24% -37% -55% -71% 0% 0% -1% -5% -22% -43% -65% 10% 20% 19% 14% -5% -31% -58% 20% 40% 42% 36% 11% -15% -47% 30% 60% 67% 59% 32% -3% -38% 40% 80% 93% 84% 52% 11% -28% 50% 100% 122% 111% 76% 28% -20% 60% 120% 154% 140% 100% 44% -10% The underlying index's annualized historical volatility rate for the five year period ended June 30, 2011 is 18.45%. The underlying index's highest one-year volatility rate during the five year period is 33.31%. The underlying index's annualized performance for the five year period ended June 30, 2011 is -2.17%. Historical underlying index volatility and performance are not indications of what the underlying index volatility and performance will be in the future. Counterparty Credit Risk - The Fund may make investments in financial instruments involving counterparties that attempt to gain exposure to a particular group of securities, index or asset class without actually purchasing those securities or investments, or to hedge a position. The Fund's use of such financial instruments, including swap agreements, involves risks that are different from those associated with ordinary portfolio securities transactions. For example, if a swap agreement counterparty defaults on its payment obligations to the Fund, this default will cause the value of your investment in the Fund to decrease. Swap agreements also may be considered to be illiquid. Currency Risk - The Fund's indirect and direct exposure to foreign currencies subjects the Fund to the risk that those currencies will decline in value relative to the U.S. Dollar, or, in the case of short positions, that the U.S. Dollar will decline in value relative to the currency being hedged. The Fund also may incur transaction costs in connection with conversions between various currencies. Depositary Receipt Risk - The Fund may hold the securities of non-U.S. companies in the form of ADRs. The underlying securities of the ADRs in the Fund's portfolio are subject to fluctuations in foreign currency exchange rates that may affect the value of the Fund's portfolio. In addition, the value of the securities underlying the ADRs may change materially when the U.S. markets are not open for trading. Investments in the underlying foreign securities also involve political and economic risks distinct from those associated with investing in the securities of U.S. issuers. Derivatives Risk - The Fund's investments in derivatives may pose risks in addition to those associated with investing directly in securities or other investments, including illiquidity of the derivatives, imperfect correlations with underlying investments or the Fund's other portfolio holdings, lack of availability and counterparty risk. Early Closing Risk - The Fund is subject to the risk that unanticipated early closings of securities exchanges and other financial markets may result in the Fund's inability to buy or sell securities or other financial instruments on that day and may cause the Fund to incur substantial trading losses. Foreign Issuer Exposure Risk - The Fund may invest in securities of foreign companies directly, or in financial instruments, such as ADRs, that are indirectly linked to the performance of foreign issuers. Foreign securities markets generally have less trading volume and less liquidity than U.S. markets, and prices in some foreign markets may fluctuate more than those of securities traded on U.S. markets. Geographic Concentration in Japan Risk - Targeting Japan could hurt the Fund's performance if Japan's economy performs poorly as a result of political and economic conditions that affect the Japanese market. Japanese stocks tend to be more volatile than their U.S. counterparts, for reasons ranging from political and economic uncertainties, to a higher risk that essential information may be incomplete or erroneous. The Fund may be more volatile than a geographically diversified equity fund. Large-Capitalization Securities Risk - The Fund is subject to the risk that large-capitalization stocks may underperform other segments of the equity market or the equity market as a whole. Leveraging Risk - The Fund achieves leveraged exposure to the underlying index through the use of derivative instruments. The more the Fund invests in leveraged instruments, the more this leverage will magnify any losses on those investments. The Fund's investment in these instruments generally requires a small investment relative to the amount of investment exposure assumed. As a result, such investments may give rise to losses that exceed the amount invested in those instruments. Since the Fund's investment strategy involves consistently applied leverage, the value of the Fund's shares will tend to increase or decrease more than the value of any increase or decrease in the underlying index. Leverage also will have the effect of magnifying tracking error. Liquidity Risk - In certain circumstances, it may be difficult for the Fund to purchase and sell particular investments within a reasonable time at a fair price. In addition, the ability of the Fund to assign an accurate daily value to certain investments may be difficult, and the Advisor may be required to fair value the investments. Market Risk - The Fund's investments in securities and derivatives, in general, are subject to market risks that may cause their prices, and therefore the Fund's value, to fluctuate over time. An investment in the Fund may lose money. Mid-Capitalization Securities Risk - The Fund is subject to the risk that medium-capitalization stocks may underperform other segments of the equity market or the equity market as a whole. Non-Diversification Risk - The Fund is considered non-diversified and can invest a greater portion of its assets in securities of individual issuers than a diversified fund. As a result, changes in the market value of a single security could cause greater fluctuations in the value of Fund shares than would occur in a diversified fund. OTC Trading Risk - Certain of the derivatives in which the Fund may invest may be traded (and privately negotiated) in the OTC market. While the OTC derivatives market is the primary trading venue for many derivatives, it is largely unregulated. As a result and similar to other privately negotiated contracts, the Fund is subject to counterparty credit risk with respect to such derivative contracts. Passive Investment Risk - The Fund is not actively managed and the Advisor does not attempt to take defensive positions in declining markets. Therefore, the Fund may be subject to greater losses in a declining market than a fund that is actively managed. Small-Capitalization Securities Risk - The Fund is subject to the risk that small-capitalization stocks may underperform other segments of the equity market or the equity market as a whole. Status as a Regulated Investment Company Risk - The Fund may realize gains from the sale or other disposition of foreign currencies and other income (including gains from options, futures or forward contracts) derived from investing in stock, securities, or foreign currencies. The Secretary of the Treasury is authorized to issue regulations that might cause the Fund, as a result of its realization of such foreign currency gains, to fail to qualify as a regulated investment company. As of the date of this Prospectus, no regulations have been issued pursuant to this authorization, but such regulations may be issued in the future. Tracking Error Risk - The Advisor may not be able to cause the Fund's performance to correlate to that of the Fund's benchmark, either on a daily or aggregate basis. Factors such as Fund expenses, imperfect correlation between the Fund's investments and those of the underlying index, rounding of share prices, changes to the composition of the underlying index, regulatory policies, high portfolio turnover rate, and the use of leverage all contribute to tracking error. Tracking error may cause the Fund's performance to be less than you expect. Trading Halt Risk - If a trading halt occurs, the Fund may temporarily be unable to purchase or sell securities, options or futures contracts. Such a trading halt near the time the Fund prices its shares may limit the Fund's ability to use leverage and may prevent the Fund from achieving its investment objective.
Risk, Lose Money	rr_RiskLoseMoney	As with all mutual funds, a shareholder is subject to the risk that his or her investment could lose money.
Risk, Nondiversified Status	rr_RiskNondiversifiedStatus	The Fund is considered non-diversified and can invest a greater portion of its assets in securities of individual issuers than a diversified fund. As a result, changes in the market value of a single security could cause greater fluctuations in the value of Fund shares than would occur in a diversified fund.
Bar Chart and Performance Table, Heading	rr_BarChartAndPerformanceTableHeading	PERFORMANCE INFORMATION -
Performance, Narrative	rr_PerformanceNarrativeTextBlock	The following bar chart shows the performance of the H-Class Shares of the Fund from year to year. The variability of performance over time provides an indication of the risks of investing in the Fund. The following table shows the performance of the H-Class Shares of the Fund as an average over different periods of time in comparison to the performance of a broad-based market index. Effective May 1, 2009, the Fund changed comparative benchmarks from the Topix 100 Index to the Nikkei 225 Stock Average. This change occurred as a result of the Fund's change in name and investment strategy. Prior to May 1, 2009, the Fund's investment strategy sought to provide 125% exposure to the Topix 100 Index; therefore, the performance and average annual total returns shown below for periods prior to May 1, 2009 may have differed had the Fund's current investment strategy, which seeks to provide 200% exposure to the Nikkei 225 Stock Average, been in effect during those periods. The Nikkei 225 Stock Average more appropriately reflects the Fund's investment universe. The figures in the bar chart and table assume the reinvestment of dividends and capital gains distributions. Of course, this past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated performance information is available on the Fund's website at www.rydex-sgi.com or by calling Rydex|SGI Client Services at 800-820-0888.
Performance, Information Illustrates Variability of Returns	rr_PerformanceInformationIllustratesVariabilityOfReturns	The variability of performance over time provides an indication of the risks of investing in the Fund.
Performance, Availability Phone Number	rr_PerformanceAvailabilityPhone	800-820-0888
Performance, Availability Website Address	rr_PerformanceAvailabilityWebSiteAddress	www.rydex-sgi.com
Performance, Past Does Not Indicate Future	rr_PerformancePastDoesNotIndicateFuture	Of course, this past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.
Bar Chart, Narrative	rr_BarChartNarrativeTextBlock	The performance information shown below for H-Class Shares is based on a calendar year. The year-to-date return for the period from January 1, 2011 through June 30, 2011 is -6.80%.
Bar Chart, Closing	rr_BarChartClosingTextBlock	Highest Quarter Return Lowest Quarter Return (quarter ended 06/30/2009) 44.17% (quarter ended 3/31/2009) -33.01%
Index No Deduction for Fees, Expenses, Taxes	rr_IndexNoDeductionForFeesExpensesTaxes	reflects no deduction for fees, expenses or taxes
Performance Table, Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns presented in the table below are calculated using highest historical 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 actual after-tax returns will depend on your specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold shares of the Fund through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table, Narrative	rr_PerformanceTableNarrativeTextBlock	The after-tax returns presented in the table below are calculated using highest historical individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Your actual after-tax returns will depend on your specific tax situation and may differ from those shown below. After-tax returns are not relevant to investors who hold shares of the Fund through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Average Annual Returns, Caption	rr_AverageAnnualReturnCaption	AVERAGE ANNUAL TOTAL RETURN (for periods ended December 31, 2010)
Japan 2x Strategy Fund (First Prospectus Summary) | Japan 2x Strategy Fund | H-Class Shares
Risk/Return:	rr_RiskReturnAbstract
Year to Date Return, Label	rr_YearToDateReturnLabel	The year-to-date return for the period
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Jun. 30, 2011
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	(6.80%)
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarter Return
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	44.17%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarter Return
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Mar. 31, 2009
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(33.01%)
Japan 2x Strategy Fund | Nikkei 225 Stock Average
Risk/Return:	rr_RiskReturnAbstract
Average Annual Returns, Label	rr_AverageAnnualReturnLabel	Nikkei 225 Stock Average (reflects no deduction for fees, expenses or taxes)
Average Annual Returns, 1 Year	rr_AverageAnnualReturnYear01	9.61%
Average Annual Returns, Since Inception	rr_AverageAnnualReturnSinceInception	(0.33%)
Average Annual Returns, Inception Date	rr_AverageAnnualReturnInceptionDate	Feb. 22, 2008
Japan 2x Strategy Fund | H-Class Shares
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.75%
Distribution (12b-1) and/or Shareholder Service Fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	0.54%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.54%
Expense Example, With Redemption, 1 Year	rr_ExpenseExampleYear01	157
Expense Example, With Redemption, 3 Years	rr_ExpenseExampleYear03	486
Expense Example, With Redemption, 5 Years	rr_ExpenseExampleYear05	839
Expense Example, With Redemption, 10 Years	rr_ExpenseExampleYear10	1,834
Annual Return 2009	rr_AnnualReturn2009	14.20%
Annual Return 2010	rr_AnnualReturn2010	12.96%
Average Annual Returns, Label	rr_AverageAnnualReturnLabel	Return Before Taxes
Average Annual Returns, 1 Year	rr_AverageAnnualReturnYear01	12.96%
Average Annual Returns, Since Inception	rr_AverageAnnualReturnSinceInception	(11.97%)
Average Annual Returns, Inception Date	rr_AverageAnnualReturnInceptionDate	Feb. 22, 2008
Japan 2x Strategy Fund | H-Class Shares | After Taxes on Distributions
Risk/Return:	rr_RiskReturnAbstract
Average Annual Returns, Label	rr_AverageAnnualReturnLabel	Return After Taxes on Distributions
Average Annual Returns, 1 Year	rr_AverageAnnualReturnYear01	12.96%
Average Annual Returns, Since Inception	rr_AverageAnnualReturnSinceInception	(11.98%)
Average Annual Returns, Inception Date	rr_AverageAnnualReturnInceptionDate	Feb. 22, 2008
Japan 2x Strategy Fund | H-Class Shares | After Taxes on Distributions and Sales
Risk/Return:	rr_RiskReturnAbstract
Average Annual Returns, Label	rr_AverageAnnualReturnLabel	Return After Taxes on Distributions and Sale of Fund Shares
Average Annual Returns, 1 Year	rr_AverageAnnualReturnYear01	8.42%
Average Annual Returns, Since Inception	rr_AverageAnnualReturnSinceInception	(9.99%)
Average Annual Returns, Inception Date	rr_AverageAnnualReturnInceptionDate	Feb. 22, 2008