Risk/Return: Risk/Return: Risk/Return [Heading] Risk/Return [Heading] Objective [Heading] Objective [Heading] Objective, Primary [Text Block] Objective, Primary [Text Block] Expense [Heading] Expense [Heading] Expense Narrative [Text Block] Expense Narrative [Text Block] Operating Expenses Caption [Text] Operating Expenses Caption [Text] Expense Example [Heading] Expense Example [Heading] Expense Example Narrative [Text Block] Expense Example Narrative [Text Block] Portfolio Turnover [Heading] Portfolio Turnover [Heading] Portfolio Turnover [Text Block] Portfolio Turnover [Text Block] Strategy [Heading] Strategy [Heading] Strategy Narrative [Text Block] Strategy Narrative [Text Block] Risk [Heading] Risk [Heading] Risk Narrative [Text Block] Risk Narrative [Text Block] Bar Chart and Performance Table [Heading] Bar Chart and Performance Table [Heading] Performance Narrative [Text Block] Performance Narrative [Text Block] Bar Chart [Heading] Bar Chart [Heading] Bar Chart Closing [Text Block] Bar Chart Closing [Text Block] Performance Table Heading Performance Table Heading Performance Table Narrative Performance Table Narrative Operating Expenses: Operating Expenses: Management Fees (as a percentage of Assets) Management Fees Distribution and Service (12b-1) Fees Distribution and Service (12b-1) Fees Other Expenses (as a percentage of Assets): Other Expenses Other Expenses Net Expenses (as a percentage of Assets) Total Annual Fund Operating Expenses Net Expenses Expense Example: Expense Example: Expense Example, with Redemption, 1 Year 1 Year 1 year Expense Example, with Redemption, 3 Years 3 Years 3 year Expense Example, with Redemption, 5 Years 5 Years 5 years Expense Example, with Redemption, 10 Years 10 Years 10 years Bar Chart Table: Bar Chart Table: Annual Return 2001 2001 Annual Return 2002 2002 Annual Return 2003 2003 Annual Return 2004 2004 Annual Return 2005 2005 Annual Return 2006 2006 Annual Return 2007 2007 Annual Return 2008 2008 Annual Return 2009 2009 Annual Return 2010 2010 Average Annual Return: Average Annual Return: Label Label 1 Year 1 year 5 Years 5 years 10 Years 10 years Document Type Document Type Document Period End Date Document Period End Date Registrant Name Registrant Name Central Index Key Central Index Key Amendment Flag Amendment Flag Trading Symbol Trading Symbol Document Creation Date Document Creation Date Document Effective Date Document Effective Date Prospectus Date Prospectus Date Portfolio Turnover, Rate Portfolio Turnover, Rate Strategy Portfolio Concentration [Text] Strategy Portfolio Concentration [Text] Risk Lose Money [Text] Risk Lose Money [Text] Risk Not Insured Depository Institution [Text] Risk Not Insured Depository Institution [Text] Performance Information Illustrates Variability of Returns [Text] Performance Information Illustrates Variability of Returns [Text] Performance Availability Website Address [Text] Performance Availability Website Address [Text] Performance Past Does Not Indicate Future [Text] Performance Past Does Not Indicate Future [Text] Highest Quarterly Return, Label Label Highest Quarterly Return, Label Highest Quarterly Return, Date Highest Quarterly Return, Date Highest Quarterly Return Highest Quarterly Return Lowest Quarterly Return, Label Label Lowest Quarterly Return, Label Lowest Quarterly Return, Date Lowest Quarterly Return, Date Lowest Quarterly Return Lowest Quarterly Return Index No Deduction for Fees, Expenses, Taxes [Text] Index No Deduction for Fees, Expenses, Taxes [Text] Performance Table Uses Highest Federal Rate Performance Table Uses Highest Federal Rate Performance Table Not Relevant to Tax Deferred Performance Table Not Relevant to Tax Deferred Series [Axis] Series [Axis] Series Series Value Line Premier Growth Fund S000007574 [Member] Share Class [Axis] Share Class [Axis] Share Classes Share Classes Value Line Premier Growth Fund C000020639 C000020639 [Member] Performance Measure [Axis] Performance Measure [Axis] Before Taxes Before Taxes S&P ® 500 Index Sp ® 500 Index [Member] After Taxes on Distributions After Taxes on Distributions After Taxes on Distributions and Sales After Taxes on Distributions and Sales Objective, Secondary [Text Block] Shareholder Fees Caption [Text] Shareholder Fees [Table] Annual Fund Operating Expenses [Table] Expense Footnotes [Text Block] Expenses Deferred Charges [Text Block] Expenses Range of Exchange Fees [Text Block] Expense Example by Year [Heading] 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] Risk Footnotes [Text Block] Risk Closing [Text Block] Bar Chart Narrative [Text Block] Bar Chart [Table] Bar Chart Footnotes [Text Block] Performance [Table] Market Index Performance [Table] Performance Table Footnotes Performance Table Closing [Text Block] Operating Expenses Column [Text] Distribution or Similar (Non 12b-1) Fees Component1 Other Expenses Component2 Other Expenses Component3 Other Expenses Acquired Fund Fees and Expenses Expenses (as a percentage of Assets) Total Expenses Fee Waiver or Reimbursement Fee Waiver or Reimbursement Expense Example, By Year, Column [Text] Column Annual Return, Column [Text] Column Annual Return, Inception Date 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 2011 Annual Return 2012 Annual Return 2013 Annual Return 2014 Since Inception Inception Date Amendment Description Shareholder Fees Column [Text] Maximum Cumulative Sales Charge (as a percentage of Offering Price) Maximum Cumulative Sales Charge (as a percentage) Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) Maximum Deferred Sales Charge (as a percentage of Offering Price) 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 (as a percentage of Amount Redeemed) Redemption Fee 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 Fee Waiver or Reimbursement over Assets, Date of Termination 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] Expense Example, No Redemption, 1 Year 1 Year Expense Example, No Redemption, 3 Years 3 Years Expense Example, No Redemption, 5 Years 5 Years Expense Example, No Redemption, 10 Years 10 Years Risk Nondiversified Status [Text] Risk Money Market Fund [Text] Risk Caption Risk Column [Text] Risk [Text] Performance One Year or Less [Text] Performance Additional Market Index [Text] Performance Availability Phone [Text] Bar Chart Does Not Reflect Sales Loads [Text] Annual Return Caption [Text] Caption 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 Performance Table Does Reflect Sales Loads Performance Table Market Index Changed 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 Prospectus: