U.S. Treasury Fund Legal Entity [Axis] Administrative Shares Share Class [Axis] Service Shares Institutional Shares Select Shares Premier Shares Government Securities Money Market Fund Administrative Shares Institutional Shares Select Shares Premier Shares Limited Duration Fund A Shares Investor Shares Return After Taxes on Distributions Performance Measure [Axis] Return After Taxes on Distributions and Sale of Fund Shares Institutional Shares BofA Merrill Lynch 1-5 Year U.S. Corporate/Government Index (reflects no deduction for expenses, fees or taxes) Moderate Duration Fund A Shares Investor Shares Institutional Shares Barclays U.S. Intermediate Aggregate Bond Index (reflects no deduction for expenses, fees or taxes) Bond Fund A Shares Investor Shares Institutional Shares Barclays U.S. Aggregate Bond Index (reflects no deduction for expenses, fees or taxes) Intermediate Tax-Free Bond Fund A Shares Investor Shares Institutional Shares Barclays U.S. Municipal Bond Index (reflects no deduction for expenses, fees or taxes) Active Core Fund A Shares Investor Shares Institutional Shares Russell 1000 Index (reflects no deduction for expenses, fees or taxes) Multi Cap Equity Income Fund A Shares Investor Shares Institutional Shares Opportunistic Fund A Shares Investor Shares Institutional Shares Return Before Taxes After Taxes on Distributions After Taxes on Distributions and Sales HFRX Equity Hedge Index (reflects no deduction for expenses, fees or taxes) S&P 500 Index (reflects no deduction for expenses, fees or taxes) World Energy Fund Class A Class C Investor Shares Institutional Shares C Shares C Shares C Shares Return Before Taxes (With Load) Return Before Taxes (No Load) MID CAP CORE EQUITY FUND Class A Class C Investor Institutional MSCI World Energy Index (reflects no deduction for expenses, fees or taxes) Russell 3000 Index (reflects no deduction for expenses, fees or taxes) Prospectus: [Table] Prospectus [Line Items] Risk/Return [Heading] Objective [Heading] Objective, Primary [Text Block] Objective, Secondary [Text Block] Expense [Heading] Expense Narrative [Text Block] Shareholder Fees Caption [Text] Shareholder Fees [Table] Operating Expenses Caption [Text] Annual Fund Operating Expenses [Table] Expense Footnotes [Text Block] Expenses Deferred Charges [Text Block] Expenses Range of Exchange Fees [Text Block] Expense Example [Heading] Expense Example by Year [Heading] Expense Example Narrative [Text Block] Expense Example by, Year, Caption [Text] Expense Example, With Redemption [Table] Expense Example, No Redemption Narrative [Text Block] Expense Example, No Redemption, By Year, Caption [Text] Expense Example, No Redemption [Table] Expense Example Footnotes [Text Block] Expense Example Closing [Text Block] Portfolio Turnover [Heading] Portfolio Turnover [Text Block] Strategy [Heading] Strategy Narrative [Text Block] Risk [Heading] Risk Narrative [Text Block] Risk Footnotes [Text Block] Risk Closing [Text Block] Bar Chart and Performance Table [Heading] Performance Narrative [Text Block] Bar Chart Narrative [Text Block] Bar Chart [Heading] Bar Chart [Table] Bar Chart Footnotes [Text Block] Bar Chart Closing [Text Block] Performance Table Heading Performance Table Narrative Performance [Table] Market Index Performance [Table] Performance Table Footnotes Performance Table Closing [Text Block] Shareholder Fees Column [Text] Maximum Cumulative Sales Charge (as a percentage of Offering Price) Maximum Cumulative Sales Charge (as a percentage) Maximum Sales Charge (Load) imposed on Purchases (as a percentage of offering price) Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of original purchase price or redemption proceeds) Maximum Deferred Sales Charge (as a percentage) Maximum Sales Charge on Reinvested Dividends and Distributions (as a percentage) Redemption Fee (as a percentage of Amount Redeemed) Redemption Fee Exchange Fee (as a percentage of Amount Redeemed) Exchange Fee Maximum Account Fee (as a percentage of Assets) Maximum Account Fee Shareholder Fee, Other Operating Expenses Column [Text] Management Fees Distribution and/or Service (12b-1) Fees Distribution or Similar (Non 12b-1) Fees Other Expenses Shareholder Servicing Fees Component3 Other Expenses Total Other Expenses Acquired Fund Fees and Expenses Total Annual Fund Operating Expenses Less Fee Waivers Total Annual Fund Operating Expenses After Fee Waivers Expense Example, By Year, Column [Text] 1 Year 3 Years 5 Years 10 Years Expense Example, No Redemption: Expense Example, No Redemption, By Year, Column [Text] Expense Example, No Redemption, 1 Year Expense Example, No Redemption, 3 Years Expense Example, No Redemption, 5 Years Expense Example, No Redemption, 10 Years Annual Return Caption [Text] Annual Return, Column [Text] Annual Return, Inception Date Annual Return 1990 Annual Return 1991 Annual Return 1992 Annual Return 1993 Annual Return 1994 Annual Return 1995 Annual Return 1996 Annual Return 1997 Annual Return 1998 Annual Return 1999 Annual Return 2000 Annual Return 2001 Annual Return 2002 Annual Return 2003 Annual Return 2004 Annual Return 2005 Annual Return 2006 Annual Return 2007 Annual Return 2008 Annual Return 2009 Annual Return 2010 Annual Return 2011 Annual Return 2012 Annual Return 2013 Annual Return 2014 Annual Return 2015 Annual Return 2016 Annual Return 2017 Annual Return 2018 Annual Return 2019 Annual Return 2020 Label 1 Year 5 Years 10 Years Since Inception Inception Date Risk/Return: Risk/Return Detail [Table] Document Type Document Period End Date Registrant Name Central Index Key Amendment Flag Amendment Description Trading Symbol Document Creation Date Document Effective Date Prospectus Date Total Annual Fund Operating Expenses Total Annual Fund Operating Expenses After Fee Waivers Fee Waiver or Reimbursement over Assets, Date of Termination Portfolio Turnover, Rate Expense Breakpoint Discounts [Text] Expense Breakpoint, Minimum Investment Required [Amount] Expense Exchange Traded Fund Commissions [Text] Expenses Represent Both Master and Feeder [Text] Expenses Explanation of Nonrecurring Account Fee [Text] Other Expenses, New Fund, Based on Estimates [Text] Acquired Fund Fees and Expenses, Based on Estimates [Text] Expenses Other Expenses Had Extraordinary Expenses Been Included [Text] Expenses Restated to Reflect Current [Text] Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text] Strategy Portfolio Concentration [Text] Risk Lose Money [Text] Risk Nondiversified Status [Text] Risk Money Market Fund [Text] Risk Not Insured Depository Institution [Text] Risk Caption Risk Column [Text] Risk [Text] Performance Information Illustrates Variability of Returns [Text] Performance One Year or Less [Text] Performance Additional Market Index [Text] Performance Availability Phone [Text] Performance Availability Website Address [Text] Performance Past Does Not Indicate Future [Text] Bar Chart Does Not Reflect Sales Loads [Text] Bar Chart, Reason Selected Class Different from Immediately Preceding Period [Text] Bar Chart, Returns for Class Not Offered in Prospectus [Text] Year to Date Return, Label Bar Chart, Year to Date Return, Date Bar Chart, Year to Date Return Highest Quarterly Return, Label Highest Quarterly Return, Date Highest Quarterly Return Lowest Quarterly Return, Label Lowest Quarterly Return, Date Lowest Quarterly Return Performance Table Does Reflect Sales Loads Performance Table Market Index Changed Index No Deduction for Fees, Expenses, Taxes [Text] Performance Table Uses Highest Federal Rate Performance Table Not Relevant to Tax Deferred Performance Table One Class of after Tax Shown [Text] Performance Table Explanation after Tax Higher Performance Table Footnotes, Reason Performance Information for Class Different from Immediately Preceding Period [Text] Caption Column Money Market Seven Day Yield, Caption [Text] Money Market Seven Day Yield Column [Text] Money Market Seven Day Yield Phone Money Market Seven Day Yield Money Market Seven Day Tax Equivalent Yield Thirty Day Yield Caption Thirty Day Yield Column [Text] Thirty Day Yield Phone Thirty Day Yield Thirty Day Tax Equivalent Yield U.S.Treasury Fund Administrative Shares Institutional Shares Select Shares Premier Shares Class C Class C Class C Russell 1000® Index (reflects no deduction for expenses, fees or taxes) Barclays U.S. Aggregate Bond Index (reflects no deduction for expenses, fees or taxes). Barclays U.S. Intermediate Aggregate Bond Index (reflects no deduction for expenses, fees or taxes). Barclays U.S. Municipal Bond Index (reflects no deduction for expenses, fees or taxes). BofA Merrill Lynch 1-5 Year U.S. Corporate/Government Index (reflects no deduction for expenses, fees or taxes). Investor shares class. Institutional shares class. Investor shares class. Institutional shares class. Investor share class. Institutional share class. Investor shares class. Institutional shares class. Investor shares class. Institutional shares class. Investor shares class. Institutional shares class. Institutional shares class. Administrative shares class. Service shares class. Select shares class. Institutional shares class. Administrative shares class. Select shares class. Administrative shares class. Select shares class. Institutional shares class. Premier shares class. Premier shares class. Premier shares class. A shares class. A shares class. A share class. A shares class. A shares class. A shares class. A share class. Investor share class. Institutional share class. The default member of the Performance Measure axis. It represents any return that is measured before taxes. Russell 1000® Index (reflects no deduction for expenses, fees or taxes). Balanced Fund. Short-Term Income Fund. U.S. Large Cap Equity Fund. U.S. Treasury Fund. Bond Fund. Cash Management Fund. Intermediate Bond Fund. Intermediate Tax-Free Bond Fund. Opportunistic Fund. HFRX Equity Hedge Index (reflects no deduction for expenses, fees or taxes). S&P 500 Index (reflects no deduction for expenses, fees or taxes). World Energy Fund. Class A Shares. Class C Shares. Investor Shares. Institutional Shares. Class C shares. Investor shares. Institutional shares. The default member of the Performance Measure axis. It represents any return that is measured before taxes. The default member of the Performance Measure axis. It represents any return that is measured before taxes. Class A. Class C. Investor. Institutional. MID CAP CORE EQUITY FUND MSCI World Energy Index (reflects no deduction for expenses, fees or taxes). Russell 3000 Index (reflects no deduction for expenses, fees or taxes). C000041650Member C000041649Member C000041652Member C000073542Member C000024286Member C000102310Member C000024299Member C000024300Member C000102309Member C000024292Member C000024293Member C000102311Member C000024301Member C000024302Member C000102306Member C000024283Member C000024284Member C000102308Member C000024287Member C000024288Member C000103431Member C000103432Member C000103433Member C000136572Member C000136571Member C000150785Member C000150786Member C000176154Member C000176155Member Expense Example, with Redemption, 1 Year Expense Example, with Redemption, 5 Years Expense Example, with Redemption, 10 Years C000041653Member C000041656Member C000041655Member C000073543Member