2.2.0.25truefalse010002 - Document - Risk/Return Summary - Variable Portfolio - {Unlabeled}falsefalsetrue1falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : Variable Portfolio - Conservative Portfolio 5/1/2010 - 4/29/2011 TwelveMonthsEnded_29Apr2011_S000028704_Memberhttp://www.sec.gov/CIK0001413032duration2010-05-01T00:00:002011-04-29T00:00:00falsefalsecfvst1413032_S000028704Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_S000028704Memberdei_DocumentInformationDocumentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli01false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://columbiamanagement.com/role/riskreturnsummaryvariableportfolio1falsefalsefalse00Variable Portfolio - Conservative PortfolioVariable Portfolio - Conservative Portfoliofalsefalsefalsefalsefalse1falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : Variable Portfolio - Conservative Portfolio 5/1/2010 - 4/29/2011 TwelveMonthsEnded_29Apr2011_S000028704_Memberhttp://www.sec.gov/CIK0001413032duration2010-05-01T00:00:002011-04-29T00:00:00falsefalsecfvst1413032_S000028704Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_S000028704Memberdei_DocumentInformationDocumentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0OthernaNo definition available.No authoritative reference available.falsefalseVariable Portfolio - Conservative Portfolio3false0rr_RiskReturnHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Summary of Variable Portfolio – Conservative Portfolio (Conservative Portfolio)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicatedReference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 falsefalseRisk/Return [Heading]4false0rr_ObjectiveHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00INVESTMENT OBJECTIVEfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseObjective [Heading]5false0rr_ObjectivePrimaryTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund seeks to provide a high level of total return that is consistent with a conservative level of risk.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseObjective, Primary [Text Block]6false0rr_ExpenseHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00FEES AND EXPENSES OF THE FUNDfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Summary Fee Table Includes the following information, in plain English under rule 421(d) under the Securities Act, after Item 2 Fees and expenses of the Fund This table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Shareholder Fees (fees paid directly from your investment) Example 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 you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be You would pay the following expenses if you did not redeem your shares The Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher. Portfolio Turnover The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover may indicate higher transaction costs. 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 __% of the average value of its whole portfolio. Instructions. A.3.instructions.6 New Funds. For purposes of this Item, a "New Fund" is a Fund that does not include in Form N-1A financial statements reporting operating results or that includes financial statements for the Fund's initial fiscal year reporting operating results for a period of 6 months or less. The following Instructions apply to New Funds.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph d -Subsection instructions falsefalseExpense [Heading]7false0rr_ExpenseNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This table describes the Fund’s fees and expenses that you may pay if you buy a variable annuity or life insurance policy and allocate your purchase payments or premiums to subaccounts that invest in the Fund. The table does not reflect any charges or expenses imposed by insurance companies on subaccounts or contracts. If such sales charges or expenses had been included, the expenses set forth below would be higher. In addition to the total annual Fund operating expenses that the Fund bears directly, the Fund’s shareholders indirectly bear the expenses of the underlying funds (or acquired funds) in which the Fund invests. The Fund’s “Acquired fund fees and expenses,” based on its allocations to the underlying funds, is as shown. Because acquired funds will have varied expense and fee levels and the Fund may own different proportions of acquired funds at different times, the amount of fees and expenses incurred by the Fund with respect to such investments will vary.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThis table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Include the narrative explanations in the order indicated. A Fund may modify the narrative explanations if the explanation contains comparable information to that shown.The narrative explanation regarding sales charge discounts is only required by a Fund that offers such discounts and should specify the minimum level of investment required to qualify for a discount. Modify the narrative explanation to state that Fund shares are sold on a national securities exchange at the end of the time periods indicated, and that brokerage commissions for buying and selling Fund shares through a broker are not reflected.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph b -Subsection instructions falsefalseExpense Narrative [Text Block]8false0rr_AnnualFundOperatingExpensesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> <div style="display:none;">~ http://columbiamanagement.com/role/AnnualFundOperatingExpensesVariablePortfolioConservativePortfolio column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfvst1413032_S000028704_Member * row dei_LegalEntityAxis compact cfvst1413032_S000028704_Member * ~</div> </div>falsefalse<div> <div style="display:none;">~ http://columbiamanagement.com/role/AnnualFundOperatingExpensesVariablePortfolioConservativePortfolio column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfvst1413032_S000028704_Member * row dei_LegalEntityAxis compact cfvst1413032_S000028704_Member * ~</div> </div>falsehttp://columbiamanagement.com/role/AnnualFundOperatingExpensesVariablePortfolioConservativePortfoliofalsefalse0200242 - 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Under an appropriate caption or a subcaption of "Other Expenses," disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 9 -Subsection table falsefalseDistribution and/or service (12b-1) fees0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00250.0025falsefalsefalsetruefalse3truetruetrue0.00250.0025falsefalsefalsetruefalseOthernanafalsefalseDistribution and/or service (12b-1) fees5falseRowprimaryElement*8false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00030.0003falsefalsefalsetruefalse3truetruetrue0.00030.0003falsefalsefalsetruefalseOtherrr:NonNegativePure4Typepure"Other Expenses" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]). "Other Expenses" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's "Other Expenses," disclose in a footnote to the table what "Other Expenses" would have been had the extraordinary expenses been included.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph c -Clause i -Subsection instructions falsefalseOther expenses0rr_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00030.0003falsefalsefalsetruefalse3truetruetrue0.00030.0003falsefalsefalsetruefalseOthernanafalsefalseOther expenses6falseRowprimaryElement*9false0rr_AcquiredFundFeesAndExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00640.0064falsefalsefalsetruefalse3truetruetrue0.00640.0064falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseAcquired fund fees and expenses0rr_AcquiredFundFeesAndExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00640.0064falsefalsefalsetruefalse3truetruetrue0.00640.0064falsefalsefalsetruefalseOthernanafalsefalseAcquired fund fees and expenses7falseRowprimaryElement*10false0rr_ExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00920.0092falsefalsefalsetruefalse3truetruetrue0.00920.0092falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses. If the Fund is a Feeder Fund, reflect the aggregate expenses of the Feeder Fund and the Master Fund in a single fee table using the captions provided. In a footnote to the fee table, state that the table and Example reflect the expenses of both the Feeder and Master Funds. If the prospectus offers more than one Class of a Multiple Class Fund or more than one Feeder Fund that invests in the same Master Fund, provide a separate response for each Class or Feeder Fund. Base the percentages of "Annual Fund Operating Expenses" on amounts incurred during the Fund's most recent fiscal year, but include in expenses amounts that would have been incurred absent expense reimbursement or fee waiver arrangements. If the Fund has changed its fiscal year and, as a result, the most recent fiscal year is less than three months, use the fiscal year prior to the most recent fiscal year as the basis for determining "Annual Fund Operating Expenses."Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph d -Subsection instructions falsefalseTotal annual fund operating expenses0rr_ExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00920.0092falsefalsefalsetruefalse3truetruetrue0.00920.0092falsefalsefalsetruefalseOthernanafalsefalseTotal annual fund operating expenses8falseRowprimaryElement*11false0rr_FeeWaiverOrReimbursementOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00000.0000[1]falsefalsefalsetruefalse3truetruetrue-0.0006-0.0006[1]falsefalsefalsetruefalseOtherrr:NonPositivePure4TypepureTotal Annual Fund Operating Expenses. If there were expense reimbursement or fee waiver arrangements that reduced any Fund operating expenses and will continue to reduce them for no less than one year from the effective date of the Fund's registration statement, a Fund may add two captions to the table one caption showing the amount of the expense reimbursement or fee waiver, and a second caption showing the Fund's net expenses after subtracting the fee reimbursement or expense waiver from the total fund operating expenses. The Fund should place these additional captions directly below the "Total Annual Fund Operating Expenses" caption of the table and should use appropriate descriptive captions, such as "Fee Waiver [and/or Expense Reimbursement]" and "Total Annual Fund Operating Expenses After Fee Waiver [and/or Expense Reimbursement]," respectively. If the Fund provides this disclosure, also disclose the period for which the expense reimbursement or fee waiver arrangement is expected to continue, and briefly describe who can terminate the arrangement and under what circumstances.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseLess: Fee waiver/expense reimbursement0rr_FeeWaiverOrReimbursementOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00000.0000falsefalsefalsetruefalse3truetruetrue-0.0006-0.0006falsefalsefalsetruefalseOthernanafalsefalseLess: Fee waiver/expense reimbursement9falseRowprimaryElement*12false0rr_NetExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00920.0092[1]falsefalsefalsetruefalse3truetruetrue0.00860.0086[1]falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table truefalseTotal annual fund and acquired fund fees and expenses after fee waiver/expense reimbursement0rr_NetExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00920.0092falsefalsefalsetruefalse3truetruetrue0.00860.0086falsefalsefalsetruefalseOthernanafalsefalseTotal annual fund and acquired fund fees and expenses after fee waiver/expense reimbursement1The investment manager and its affiliates have contractually agreed to waive certain fees and to reimburse certain expenses for all share classes until at least April 30, 2012, unless sooner terminated at the sole discretion of the Fund's Board. Any amounts waived will not be reimbursed by the Fund. Under this agreement, net fund expenses (including fees and expenses of acquired funds) will not exceed 0.86% for Class 4 shares of the Fund through April 30, 2012, unless sooner terminated at the sole discretion of the Fund's Board. 39Annual Fund Operating Expenses UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to OperatingExpensesData.No authoritative reference available.falsefalseAnnual Fund Operating Expenses [Table]9false0rr_ExpenseExampleHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00ExamplefalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringHeading for Expense Example.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseExpense Example [Heading]10false0rr_ExpenseExampleNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The 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 a subaccount that invests in the Fund for the time periods indicated and then redeem all of your investment 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. The Example includes contractual commitments to waive fees and reimburse expenses, if any, expiring as indicated in the preceding table. Although your actual costs may be higher or lower, based on these assumptions your costs would be:falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThe Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection example falsefalseExpense Example Narrative [Text Block]11false0rr_ExpenseExampleWithRedemptionTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> <div style="display:none;">~ http://columbiamanagement.com/role/ExpenseExampleVariablePortfolioConservativePortfolio column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfvst1413032_S000028704_Member * row dei_LegalEntityAxis compact cfvst1413032_S000028704_Member * ~</div> </div>falsefalse<div> <div style="display:none;">~ http://columbiamanagement.com/role/ExpenseExampleVariablePortfolioConservativePortfolio column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfvst1413032_S000028704_Member * row dei_LegalEntityAxis compact cfvst1413032_S000028704_Member * ~</div> </div>truehttp://columbiamanagement.com/role/ExpenseExampleVariablePortfolioConservativePortfoliofalsefalse0200342 - Schedule - Expense Example {Transposed}truefalsefalse1falseColumnprimaryElement*4false0rr_ExpenseExampleByYearColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class 2falsefalsefalsetruefalse2falsefalsefalse00Class 4falsefalsefalsetruefalseOtherus-types:textBlockItemTypestringThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalseExpense Example, By Year, Column [Text]falseUSDfalsefalse$2falseColumnprimaryElement*5false0rr_ExpenseExampleYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue9494falsefalsefalsetruefalse2truefalsetrue8888falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalse1 yearfalseUSDfalsefalse$3falseColumnprimaryElement*6false0rr_ExpenseExampleYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue294294falsefalsefalsetruefalse2truefalsetrue281281falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse3 yearsfalseUSDfalsefalse$4falseColumnprimaryElement*7false0rr_ExpenseExampleYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue510510falsefalsefalsetruefalse2truefalsetrue498498falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse5 yearsfalseUSDfalsefalse$5falseColumnprimaryElement*8false0rr_ExpenseExampleYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue11361136falsefalsefalsetruefalse2truefalsetrue11241124falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse10 yearsfalseUSDfalsefalse$1falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-01T00:00:002011-04-29T00:00:00falsefalseVariable Portfolio - Conservative Portfoliodei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_S000028704Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass 2, VP - Conservative Portfoliorr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_C000087827Memberrr_ProspectusShareClassAxisexplicitMemberVariable Portfolio - Conservative PortfolioClass 2, VP - Conservative PortfolioUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class 2Class 2falsefalsefalsetruefalse2truefalsetrue9494falsefalsefalsetruefalse3truefalsetrue294294falsefalsefalsetruefalse4truefalsetrue510510falsefalsefalsetruefalse5truefalsetrue11361136falsefalsefalsetruefalseOthernanafalsefalseClass 2, VP - Conservative Portfolio2falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-01T00:00:002011-04-29T00:00:00falsefalseVariable Portfolio - Conservative Portfoliodei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_S000028704Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass 4, VP - Conservative Portfoliorr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_C000087826Memberrr_ProspectusShareClassAxisexplicitMemberVariable Portfolio - Conservative PortfolioClass 4, VP - Conservative PortfolioUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class 4Class 4falsefalsefalsetruefalse2truefalsetrue8888falsefalsefalsetruefalse3truefalsetrue281281falsefalsefalsetruefalse4truefalsetrue498498falsefalsefalsetruefalse5truefalsetrue11241124falsefalsefalsetruefalseOthernanafalsefalseClass 4, VP - Conservative Portfolio52Expense Example Variable Portfolio - Conservative Portfolio (USD $)UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ExpenseExample.No authoritative reference available.falsefalseExpense Example, With Redemption [Table]12false0rr_ExpenseExampleClosingTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This Example does not reflect the charges or expenses that apply to the subaccounts or the contracts. If such charges or expenses had been included, your costs set forth above would have been higher.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThe Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseExpense Example Closing [Text Block]13false0rr_PortfolioTurnoverHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Portfolio TurnoverfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 5 -Subsection instructions falsefalsePortfolio Turnover [Heading]14false0rr_PortfolioTurnoverTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund will indirectly bear the expenses associated with portfolio turnover of the underlying funds. The underlying funds pay transaction costs, such as commissions, when they buy and sell securities (or “turn over” their portfolios). An underlying fund’s higher portfolio turnover rate may indicate higher transaction costs. 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 28% of the average value of its portfolio.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subsection example falsefalsePortfolio Turnover [Text Block]15false0rr_StrategyHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PRINCIPAL INVESTMENT STRATEGIES OF THE FUNDfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy [Heading]16false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund is a “fund of funds” and seeks to achieve its objective by investing in a combination of underlying funds representing three primary asset classes: equity, fixed income and cash. The Fund may invest in derivatives such as index futures, Treasury futures, currency forwards, index-based total return swaps and indexed-based credit default swaps. Under normal market conditions, the Fund intends to invest in each asset class within the following target asset allocation ranges:</p><div style="font-face: times new roman; font-size:10pt" ><table style="font-size:10pt" cellpadding="0" cellspacing="0" border="0" width="100%"><tr><td width="30%"> </td><td width="10%"> </td><td width="20%"> </td><td width="20%"> </td><td width="20%"> </td></tr><tr><td > </td><td align="center"><b>Equity</b></td><td align="right"><b>Fixed Income</b></td><td align="center"><b>Cash</b></td><td > </td></tr><tr style="font-size:2pt"><td colspan="5"> </td></tr><tr><td > </td><td align="center">15-25%</td><td align="right">65-75%</td><td align="center">5-15%</td><td > </td></tr></table></div><p>Market appreciation or depreciation may cause the Fund to be temporarily outside the range identified in the table. The investment manager may modify the target allocation ranges only upon approval of the Fund’s Board of Trustees (the Board).</p><p>In selecting the proportion of the Fund’s assets to be invested within and across each of the three primary asset classes, the investment manager considers the independent analysis of Morningstar Associates (Morningstar), an independent investment consultant, on a broad range of aspects related to the management of the Fund including, but not limited to, the Fund’s asset allocation targets, the performance of the underlying funds, the types of investment categories represented by the underlying funds, and the consideration of additional underlying funds. The investment manager retains full discretion over the Fund’s investment activities. The Fund may also invest in derivative instruments to achieve its objective.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy Narrative [Text Block]17false0rr_RiskHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PRINCIPAL RISKS OF INVESTING IN THE FUNDfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subsection b falsefalseRisk [Heading]18false0rr_RiskNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>Please remember that with any mutual fund investment you may lose money. Principal risks associated with an investment in the Fund include specific risks relating to the investment in the Fund based on its investment process, and certain general risks based on its “funds of funds” structure. These risks are identified below.</p><p><b>Affiliated Fund Risk.</b> The risk that the investment manager may have potential conflicts of interest in selecting underlying funds because the fees paid to it by some underlying funds are higher than the fees paid by other underlying funds.</p><p><b> Active Management/Allocation Risk.</b> The risk that the investment manager’s evaluations regarding asset classes or underlying funds and the Fund’s allocations thereto may be incorrect. The ability of the Fund to realize its investment objective will depend, in part, on the extent to which the underlying funds realize their investment objectives. There is no guarantee that the underlying funds will achieve their investment objectives. The Fund is exposed to the same risks as the underlying funds in direct proportion to the allocation of its assets among the underlying funds.</p><p><b>Derivatives Risk.</b> Losses involving derivative instruments may be substantial, because a relatively small price movement in the underlying security(ies), instrument, currency or index may result in a substantial loss for the Fund. In addition to the potential for increased losses, the use of derivative instruments may lead to increased volatility within the Fund. Derivatives will typically increase the Fund’s exposure to principal risks to which it is otherwise exposed, and may expose the Fund to additional risks, including leverage risk, hedging risk, correlation risk, and liquidity risk.</p><p><b>Risks of Underlying Funds.</b> By investing in a combination of underlying funds, the Fund has exposure to the risks associated with many areas of the market. Since Conservative Portfolio intends to invest a significant portion of its assets in fixed income asset classes, the Fund may have higher exposure to the following principal risks of the underlying funds: Counterparty Risk, Credit Risk, Derivatives Risk, Interest Rate Risk, Issuer Risk and Prepayment and Extension Risk. Also, in addition to the Fund’s operating expenses, you will indirectly bear the operating expenses of the underlying funds. Thus, the expenses you bear as an investor in the Fund will be higher than if you invested directly in the underlying funds. A description of the more common principal risks to which the underlying funds (and thus, the Fund) are subject to are identified under “More Information about the Funds — Principal Risks of Investing in the Funds — Certain Principal Risks of the Underlying Funds.” A more complete list of principal risks associated with direct investment in the underlying funds is set forth in Appendix B. Additional risks of the underlying funds are set forth in the SAI.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringNarrative Risk Disclosure. A Fund may, in responding to this Item, describe the types of investors for whom the Fund is intended or the types of investment goals that may be consistent with an investment in the Fund.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subparagraph i -Clause instruction -Subsection b falsefalseRisk Narrative [Text Block]19false0rr_BarChartAndPerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PAST PERFORMANCEfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart and Performance Table [Heading]20false0rr_PerformanceNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The bar chart and past performance table are not presented because the Fund has not had a full calendar year of operations. The Fund began operations on May 7, 2010. When performance is available, Conservative Portfolio intends to compare its performance to the Barclays Capital U.S. Aggregate Bond Index and a Blended Index, consisting of 70% Barclays Capital U.S. Aggregate Bond Index, 14% Russell 3000 Index, 6% Morgan Stanley Capital International (MSCI) All Country World Index (ACWI) ex-US and 10% Citigroup 3-month U.S. Treasury Bill Index.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalsePerformance Narrative [Text Block]21false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://columbiamanagement.com/role/riskreturnsummaryvariableportfolio1falsefalsefalse00Variable Portfolio - Moderately Conservative PortfolioVariable Portfolio - Moderately Conservative Portfoliofalsefalsefalsefalsefalse2falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : Variable Portfolio - Moderately Conservative Portfolio 5/1/2010 - 4/29/2011 TwelveMonthsEnded_29Apr2011_S000028703_Memberhttp://www.sec.gov/CIK0001413032duration2010-05-01T00:00:002011-04-29T00:00:00falsefalsecfvst1413032_S000028703Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_S000028703Memberdei_DocumentInformationDocumentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0OthernaNo definition available.No authoritative reference available.falsefalseVariable Portfolio - Moderately Conservative Portfolio23false0rr_RiskReturnHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Summary of Variable Portfolio – Moderately Conservative Portfolio (Moderately Conservative Portfolio)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicatedReference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 falsefalseRisk/Return [Heading]24false0rr_ObjectiveHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00INVESTMENT OBJECTIVEfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseObjective [Heading]25false0rr_ObjectivePrimaryTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund seeks to provide a high level of total return that is consistent with a moderately conservative level of risk.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. 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Shareholder Fees (fees paid directly from your investment) Example 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 you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be You would pay the following expenses if you did not redeem your shares The Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher. Portfolio Turnover The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover may indicate higher transaction costs. 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 __% of the average value of its whole portfolio. Instructions. A.3.instructions.6 New Funds. For purposes of this Item, a "New Fund" is a Fund that does not include in Form N-1A financial statements reporting operating results or that includes financial statements for the Fund's initial fiscal year reporting operating results for a period of 6 months or less. The following Instructions apply to New Funds.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph d -Subsection instructions falsefalseExpense [Heading]27false0rr_ExpenseNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This table describes the Fund’s fees and expenses that you may pay if you buy a variable annuity or life insurance policy and allocate your purchase payments or premiums to subaccounts that invest in the Fund. The table does not reflect any charges or expenses imposed by insurance companies on subaccounts or contracts. If such sales charges or expenses had been included, the expenses set forth below would be higher. In addition to the total annual Fund operating expenses that the Fund bears directly, the Fund’s shareholders indirectly bear the expenses of the underlying funds (or acquired funds) in which the Fund invests. The Fund’s “Acquired fund fees and expenses,” based on its allocations to the underlying funds, is as shown. Because acquired funds will have varied expense and fee levels and the Fund may own different proportions of acquired funds at different times, the amount of fees and expenses incurred by the Fund with respect to such investments will vary.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThis table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Include the narrative explanations in the order indicated. A Fund may modify the narrative explanations if the explanation contains comparable information to that shown.The narrative explanation regarding sales charge discounts is only required by a Fund that offers such discounts and should specify the minimum level of investment required to qualify for a discount. Modify the narrative explanation to state that Fund shares are sold on a national securities exchange at the end of the time periods indicated, and that brokerage commissions for buying and selling Fund shares through a broker are not reflected.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph b -Subsection instructions falsefalseExpense Narrative [Text Block]28false0rr_AnnualFundOperatingExpensesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> <div style="display:none;">~ http://columbiamanagement.com/role/AnnualFundOperatingExpensesVariablePortfolioModeratelyConservativePortfolio column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfvst1413032_S000028703_Member * row dei_LegalEntityAxis compact cfvst1413032_S000028703_Member * ~</div> </div>falsefalse<div> <div style="display:none;">~ http://columbiamanagement.com/role/AnnualFundOperatingExpensesVariablePortfolioModeratelyConservativePortfolio column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfvst1413032_S000028703_Member * row dei_LegalEntityAxis compact cfvst1413032_S000028703_Member * ~</div> </div>falsehttp://columbiamanagement.com/role/AnnualFundOperatingExpensesVariablePortfolioModeratelyConservativePortfoliofalsefalse0200243 - 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Under an appropriate caption or a subcaption of "Other Expenses," disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 9 -Subsection table falsefalseDistribution and/or service (12b-1) fees0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00250.0025falsefalsefalsetruefalse3truetruetrue0.00250.0025falsefalsefalsetruefalseOthernanafalsefalseDistribution and/or service (12b-1) fees5falseRowprimaryElement*8false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00020.0002falsefalsefalsetruefalse3truetruetrue0.00020.0002falsefalsefalsetruefalseOtherrr:NonNegativePure4Typepure"Other Expenses" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]). "Other Expenses" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's "Other Expenses," disclose in a footnote to the table what "Other Expenses" would have been had the extraordinary expenses been included.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph c -Clause i -Subsection instructions falsefalseOther expenses0rr_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00020.0002falsefalsefalsetruefalse3truetruetrue0.00020.0002falsefalsefalsetruefalseOthernanafalsefalseOther expenses6falseRowprimaryElement*9false0rr_AcquiredFundFeesAndExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00690.0069falsefalsefalsetruefalse3truetruetrue0.00690.0069falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseAcquired fund fees and expenses0rr_AcquiredFundFeesAndExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00690.0069falsefalsefalsetruefalse3truetruetrue0.00690.0069falsefalsefalsetruefalseOthernanafalsefalseAcquired fund fees and expenses7falseRowprimaryElement*10false0rr_ExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00960.0096falsefalsefalsetruefalse3truetruetrue0.00960.0096falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses. If the Fund is a Feeder Fund, reflect the aggregate expenses of the Feeder Fund and the Master Fund in a single fee table using the captions provided. In a footnote to the fee table, state that the table and Example reflect the expenses of both the Feeder and Master Funds. If the prospectus offers more than one Class of a Multiple Class Fund or more than one Feeder Fund that invests in the same Master Fund, provide a separate response for each Class or Feeder Fund. Base the percentages of "Annual Fund Operating Expenses" on amounts incurred during the Fund's most recent fiscal year, but include in expenses amounts that would have been incurred absent expense reimbursement or fee waiver arrangements. If the Fund has changed its fiscal year and, as a result, the most recent fiscal year is less than three months, use the fiscal year prior to the most recent fiscal year as the basis for determining "Annual Fund Operating Expenses."Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph d -Subsection instructions falsefalseTotal annual fund operating expenses0rr_ExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00960.0096falsefalsefalsetruefalse3truetruetrue0.00960.0096falsefalsefalsetruefalseOthernanafalsefalseTotal annual fund operating expenses8falseRowprimaryElement*11false0rr_FeeWaiverOrReimbursementOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00000.0000[1]falsefalsefalsetruefalse3truetruetrue-0.0006-0.0006[1]falsefalsefalsetruefalseOtherrr:NonPositivePure4TypepureTotal Annual Fund Operating Expenses. If there were expense reimbursement or fee waiver arrangements that reduced any Fund operating expenses and will continue to reduce them for no less than one year from the effective date of the Fund's registration statement, a Fund may add two captions to the table one caption showing the amount of the expense reimbursement or fee waiver, and a second caption showing the Fund's net expenses after subtracting the fee reimbursement or expense waiver from the total fund operating expenses. The Fund should place these additional captions directly below the "Total Annual Fund Operating Expenses" caption of the table and should use appropriate descriptive captions, such as "Fee Waiver [and/or Expense Reimbursement]" and "Total Annual Fund Operating Expenses After Fee Waiver [and/or Expense Reimbursement]," respectively. If the Fund provides this disclosure, also disclose the period for which the expense reimbursement or fee waiver arrangement is expected to continue, and briefly describe who can terminate the arrangement and under what circumstances.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseLess: Fee waiver/expense reimbursement0rr_FeeWaiverOrReimbursementOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00000.0000falsefalsefalsetruefalse3truetruetrue-0.0006-0.0006falsefalsefalsetruefalseOthernanafalsefalseLess: Fee waiver/expense reimbursement9falseRowprimaryElement*12false0rr_NetExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00960.0096[1]falsefalsefalsetruefalse3truetruetrue0.00900.0090[1]falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table truefalseTotal annual fund and acquired fund fees and expenses after fee waiver/expense reimbursement0rr_NetExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00960.0096falsefalsefalsetruefalse3truetruetrue0.00900.0090falsefalsefalsetruefalseOthernanafalsefalseTotal annual fund and acquired fund fees and expenses after fee waiver/expense reimbursement1The investment manager and its affiliates have contractually agreed to waive certain fees and to reimburse certain expenses for all share classes until at least April 30, 2012, unless sooner terminated at the sole discretion of the Fund's Board. Any amounts waived will not be reimbursed by the Fund. Under this agreement, net fund expenses (including fees and expenses of acquired funds) will not exceed 0.90% for Class 4 shares of the Fund through April 30 2012, unless sooner terminated at the sole discretion of the Fund's Board. 39Annual Fund Operating Expenses UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to OperatingExpensesData.No authoritative reference available.falsefalseAnnual Fund Operating Expenses [Table]29false0rr_ExpenseExampleHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00ExamplefalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringHeading for Expense Example.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseExpense Example [Heading]30false0rr_ExpenseExampleNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The 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 a subaccount that invests in the Fund for the time periods indicated and then redeem all of your investment 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. The Example includes contractual commitments to waive fees and reimburse expenses, if any, expiring as indicated in the preceding table. Although your actual costs may be higher or lower, based on these assumptions your costs would be:falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThe Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection example falsefalseExpense Example Narrative [Text Block]31false0rr_ExpenseExampleWithRedemptionTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> <div style="display:none;">~ http://columbiamanagement.com/role/ExpenseExampleVariablePortfolioModeratelyConservativePortfolio column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfvst1413032_S000028703_Member * row dei_LegalEntityAxis compact cfvst1413032_S000028703_Member * ~</div> </div>falsefalse<div> <div style="display:none;">~ http://columbiamanagement.com/role/ExpenseExampleVariablePortfolioModeratelyConservativePortfolio column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfvst1413032_S000028703_Member * row dei_LegalEntityAxis compact cfvst1413032_S000028703_Member * ~</div> </div>truehttp://columbiamanagement.com/role/ExpenseExampleVariablePortfolioModeratelyConservativePortfoliofalsefalse0200343 - Schedule - Expense Example {Transposed}truefalsefalse1falseColumnprimaryElement*4false0rr_ExpenseExampleByYearColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class 2falsefalsefalsetruefalse2falsefalsefalse00Class 4falsefalsefalsetruefalseOtherus-types:textBlockItemTypestringThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalseExpense Example, By Year, Column [Text]falseUSDfalsefalse$2falseColumnprimaryElement*5false0rr_ExpenseExampleYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue9898falsefalsefalsetruefalse2truefalsetrue9292falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalse1 yearfalseUSDfalsefalse$3falseColumnprimaryElement*6false0rr_ExpenseExampleYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue307307falsefalsefalsetruefalse2truefalsetrue294294falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse3 yearsfalseUSDfalsefalse$4falseColumnprimaryElement*7false0rr_ExpenseExampleYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue533533falsefalsefalsetruefalse2truefalsetrue521521falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse5 yearsfalseUSDfalsefalse$5falseColumnprimaryElement*8false0rr_ExpenseExampleYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue11851185falsefalsefalsetruefalse2truefalsetrue11741174falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse10 yearsfalseUSDfalsefalse$1falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-01T00:00:002011-04-29T00:00:00falsefalseVariable Portfolio - Moderately Conservative Portfoliodei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_S000028703Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass 2, VP - Moderately Conservative Portfoliorr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_C000087824Memberrr_ProspectusShareClassAxisexplicitMemberVariable Portfolio - Moderately Conservative PortfolioClass 2, VP - Moderately Conservative PortfolioUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class 2Class 2falsefalsefalsetruefalse2truefalsetrue9898falsefalsefalsetruefalse3truefalsetrue307307falsefalsefalsetruefalse4truefalsetrue533533falsefalsefalsetruefalse5truefalsetrue11851185falsefalsefalsetruefalseOthernanafalsefalseClass 2, VP - Moderately Conservative Portfolio2falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-01T00:00:002011-04-29T00:00:00falsefalseVariable Portfolio - Moderately Conservative Portfoliodei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_S000028703Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass 4, VP - Moderately Conservative Portfoliorr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_C000087825Memberrr_ProspectusShareClassAxisexplicitMemberVariable Portfolio - Moderately Conservative PortfolioClass 4, VP - Moderately Conservative PortfolioUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class 4Class 4falsefalsefalsetruefalse2truefalsetrue9292falsefalsefalsetruefalse3truefalsetrue294294falsefalsefalsetruefalse4truefalsetrue521521falsefalsefalsetruefalse5truefalsetrue11741174falsefalsefalsetruefalseOthernanafalsefalseClass 4, VP - Moderately Conservative Portfolio52Expense Example Variable Portfolio - Moderately Conservative Portfolio (USD $)UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ExpenseExample.No authoritative reference available.falsefalseExpense Example, With Redemption [Table]32false0rr_ExpenseExampleClosingTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This Example does not reflect the charges or expenses that apply to the subaccounts or the contracts. If such charges or expenses had been included, your costs set forth above would have been higher.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThe Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseExpense Example Closing [Text Block]33false0rr_PortfolioTurnoverHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Portfolio TurnoverfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 5 -Subsection instructions falsefalsePortfolio Turnover [Heading]34false0rr_PortfolioTurnoverTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund will indirectly bear the expenses associated with portfolio turnover of the underlying funds. The underlying funds pay transaction costs, such as commissions, when they buy and sell securities (or “turn over” their portfolio). An underlying fund’s higher portfolio turnover rate may indicate higher transaction costs. 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 29% of the average value of its portfolio.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subsection example falsefalsePortfolio Turnover [Text Block]35false0rr_StrategyHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PRINCIPAL INVESTMENT STRATEGIES OF THE FUNDfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy [Heading]36false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund is a “fund of funds” and seeks to achieve its objective by investing in a combination of underlying funds representing three primary asset classes: equity, fixed income and cash. The Fund may invest in derivatives such as index futures, Treasury futures, currency forwards, index-based total return swaps and indexed-based credit default swaps. Under normal market conditions, the Fund intends to invest in each asset class within the following target asset allocation ranges:</p><div style="font-face: times new roman; font-size:10pt" ><table style="font-size:10pt" cellpadding="0" cellspacing="0" border="0" width="100%"><tr><td width="30%"> </td><td width="10%"> </td><td width="20%"> </td><td width="20%"> </td><td width="20%"> </td></tr><tr><td > </td><td align="center"><b>Equity</b></td><td align="right"><b>Fixed Income</b></td><td align="center"><b>Cash</b></td><td > </td></tr><tr style="font-size:2pt"><td colspan="5"> </td></tr><tr><td > </td><td align="center">30-40%</td><td align="right">55-65%</td><td align="center">0-10%</td><td > </td></tr></table></div><p>Market appreciation or depreciation may cause the Fund to be temporarily outside the range identified in the table. The investment manager may modify the target allocation ranges only upon approval of the Fund’s Board of Trustees (the Board).</p><p>In selecting the proportion of the Fund’s assets to be invested within and across each of the three primary asset classes, the investment manager considers the independent analysis of Morningstar Associates (Morningstar), an independent investment consultant, on a broad range of aspects related to the management of the Fund including, but not limited to, the Fund’s asset allocation targets, the performance of the underlying funds, the types of investment categories represented by the underlying funds, and the consideration of additional underlying funds. The investment manager retains full discretion over the Fund’s investment activities. The Fund may also invest in derivative instruments to achieve its objective.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy Narrative [Text Block]37false0rr_RiskHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PRINCIPAL RISKS OF INVESTING IN THE FUNDfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subsection b falsefalseRisk [Heading]38false0rr_RiskNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>Please remember that with any mutual fund investment you may lose money. Principal risks associated with an investment in the Fund include specific risks relating to the investment in the Fund based on its investment process, and certain general risks based on its “funds of funds” structure. These risks are identified below.</p><p><b>Affiliated Fund Risk.</b> The risk that the investment manager may have potential conflicts of interest in selecting underlying funds because the fees paid to it by some underlying funds are higher than the fees paid by other underlying funds.</p><p><b>Active Management/Allocation Risk.</b> The risk that the investment manager’s evaluations regarding asset classes or underlying funds and the Fund’s allocations thereto may be incorrect. The ability of the Fund to realize its investment objective will depend, in part, on the extent to which the underlying funds realize their investment objectives. There is no guarantee that the underlying funds will achieve their investment objectives. The Fund is exposed to the same risks as the underlying funds in direct proportion to the allocation of its assets among the underlying funds.</p><p><b>Derivatives Risk.</b> Losses involving derivative instruments may be substantial, because a relatively small price movement in the underlying security(ies), instrument, currency or index may result in a substantial loss for the Fund. In addition to the potential for increased losses, the use of derivative instruments may lead to increased volatility within the Fund. Derivatives will typically increase the Fund’s exposure to principal risks to which it is otherwise exposed, and may expose the Fund to additional risks, including leverage risk, hedging risk, correlation risk, and liquidity risk.</p><p><b>Risks of Underlying Funds.</b> By investing in a combination of underlying funds, the Fund has exposure to the risks associated with many areas of the market. Since Moderately Conservative Portfolio intends to invest a significant portion of its assets in fixed income asset classes, the Fund may have higher exposure to the following principal risks of the underlying funds: Counterparty Risk, Credit Risk, Derivatives Risk, Interest Rate Risk, Issuer Risk and Prepayment and Extension Risk. Also, in addition to the Fund’s operating expenses, you will indirectly bear the operating expenses of the underlying funds. Thus, the expenses you bear as an investor in the Fund will be higher than if you invested directly in the underlying funds. A description of the more common principal risks to which the underlying funds (and thus, the Fund) are subject to are identified under “More Information about the Funds — Principal Risks of Investing in the Funds — Certain Principal Risks of the Underlying Funds.” A more complete list of principal risks associated with direct investment in the underlying funds is set forth in Appendix B. Additional risks of the underlying funds are set forth in the SAI.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringNarrative Risk Disclosure. A Fund may, in responding to this Item, describe the types of investors for whom the Fund is intended or the types of investment goals that may be consistent with an investment in the Fund.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subparagraph i -Clause instruction -Subsection b falsefalseRisk Narrative [Text Block]39false0rr_BarChartAndPerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PAST PERFORMANCEfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart and Performance Table [Heading]40false0rr_PerformanceNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The bar chart and past performance table are not presented because the Fund has not had a full calendar year of operations. The Fund began operations on May 7, 2010. When performance is available, Moderately Conservative Portfolio intends to compare its performance to the Barclays Capital U.S. Aggregate Bond Index and a Blended Index, consisting of 60% Barclays Capital U.S. Aggregate Bond Index, 24.5% Russell 3000 Index, 10.5% Morgan Stanley Capital International (MSCI) All Country World Index (ACWI) ex-US and 5% Citigroup 3-month U.S. Treasury Bill Index.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalsePerformance Narrative [Text Block]41false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://columbiamanagement.com/role/riskreturnsummaryvariableportfolio1falsefalsefalse00Variable Portfolio - Moderate PortfolioVariable Portfolio - Moderate Portfoliofalsefalsefalsefalsefalse3falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : Variable Portfolio - Moderate Portfolio 5/1/2010 - 4/29/2011 TwelveMonthsEnded_29Apr2011_S000028702_Memberhttp://www.sec.gov/CIK0001413032duration2010-05-01T00:00:002011-04-29T00:00:00falsefalsecfvst1413032_S000028702Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_S000028702Memberdei_DocumentInformationDocumentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0OthernaNo definition available.No authoritative reference available.falsefalseVariable Portfolio - Moderate Portfolio43false0rr_RiskReturnHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Summary of Variable Portfolio – Moderate Portfolio (Moderate Portfolio)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicatedReference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 falsefalseRisk/Return [Heading]44false0rr_ObjectiveHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00INVESTMENT OBJECTIVEfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseObjective [Heading]45false0rr_ObjectivePrimaryTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund seeks to provide a high level of total return that is consistent with a moderate level of risk.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseObjective, Primary [Text Block]46false0rr_ExpenseHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00FEES AND EXPENSES OF THE FUNDfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Summary Fee Table Includes the following information, in plain English under rule 421(d) under the Securities Act, after Item 2 Fees and expenses of the Fund This table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Shareholder Fees (fees paid directly from your investment) Example 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 you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be You would pay the following expenses if you did not redeem your shares The Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher. Portfolio Turnover The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover may indicate higher transaction costs. 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 __% of the average value of its whole portfolio. Instructions. A.3.instructions.6 New Funds. For purposes of this Item, a "New Fund" is a Fund that does not include in Form N-1A financial statements reporting operating results or that includes financial statements for the Fund's initial fiscal year reporting operating results for a period of 6 months or less. The following Instructions apply to New Funds.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph d -Subsection instructions falsefalseExpense [Heading]47false0rr_ExpenseNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This table describes the Fund’s fees and expenses that you may pay if you buy a variable annuity or life insurance policy and allocate your purchase payments or premiums to subaccounts that invest in the Fund. The table does not reflect any charges or expenses imposed by insurance companies on subaccounts or contracts. If such sales charges or expenses had been included, the expenses set forth below would be higher. In addition to the total annual Fund operating expenses that the Fund bears directly, the Fund’s shareholders indirectly bear the expenses of the underlying funds (or acquired funds) in which the Fund invests. The Fund’s “Acquired fund fees and expenses,” based on its allocations to the underlying funds, is as shown. Because acquired funds will have varied expense and fee levels and the Fund may own different proportions of acquired funds at different times, the amount of fees and expenses incurred by the Fund with respect to such investments will vary.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThis table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Include the narrative explanations in the order indicated. A Fund may modify the narrative explanations if the explanation contains comparable information to that shown.The narrative explanation regarding sales charge discounts is only required by a Fund that offers such discounts and should specify the minimum level of investment required to qualify for a discount. Modify the narrative explanation to state that Fund shares are sold on a national securities exchange at the end of the time periods indicated, and that brokerage commissions for buying and selling Fund shares through a broker are not reflected.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph b -Subsection instructions falsefalseExpense Narrative [Text Block]48false0rr_AnnualFundOperatingExpensesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> <div style="display:none;">~ http://columbiamanagement.com/role/AnnualFundOperatingExpensesVariablePortfolioModeratePortfolio column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfvst1413032_S000028702_Member * row dei_LegalEntityAxis compact cfvst1413032_S000028702_Member * ~</div> </div>falsefalse<div> <div style="display:none;">~ http://columbiamanagement.com/role/AnnualFundOperatingExpensesVariablePortfolioModeratePortfolio column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfvst1413032_S000028702_Member * row dei_LegalEntityAxis compact cfvst1413032_S000028702_Member * ~</div> </div>falsehttp://columbiamanagement.com/role/AnnualFundOperatingExpensesVariablePortfolioModeratePortfoliofalsefalse0200244 - 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Under an appropriate caption or a subcaption of "Other Expenses," disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 9 -Subsection table falsefalseDistribution and/or service (12b-1) fees0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00250.0025falsefalsefalsetruefalse3truetruetrue0.00250.0025falsefalsefalsetruefalseOthernanafalsefalseDistribution and/or service (12b-1) fees5falseRowprimaryElement*8false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00020.0002falsefalsefalsetruefalse3truetruetrue0.00020.0002falsefalsefalsetruefalseOtherrr:NonNegativePure4Typepure"Other Expenses" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]). "Other Expenses" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's "Other Expenses," disclose in a footnote to the table what "Other Expenses" would have been had the extraordinary expenses been included.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph c -Clause i -Subsection instructions falsefalseOther expenses0rr_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00020.0002falsefalsefalsetruefalse3truetruetrue0.00020.0002falsefalsefalsetruefalseOthernanafalsefalseOther expenses6falseRowprimaryElement*9false0rr_AcquiredFundFeesAndExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00750.0075falsefalsefalsetruefalse3truetruetrue0.00750.0075falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseAcquired fund fees and expenses0rr_AcquiredFundFeesAndExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00750.0075falsefalsefalsetruefalse3truetruetrue0.00750.0075falsefalsefalsetruefalseOthernanafalsefalseAcquired fund fees and expenses7falseRowprimaryElement*10false0rr_ExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.01020.0102falsefalsefalsetruefalse3truetruetrue0.01020.0102falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses. If the Fund is a Feeder Fund, reflect the aggregate expenses of the Feeder Fund and the Master Fund in a single fee table using the captions provided. In a footnote to the fee table, state that the table and Example reflect the expenses of both the Feeder and Master Funds. If the prospectus offers more than one Class of a Multiple Class Fund or more than one Feeder Fund that invests in the same Master Fund, provide a separate response for each Class or Feeder Fund. Base the percentages of "Annual Fund Operating Expenses" on amounts incurred during the Fund's most recent fiscal year, but include in expenses amounts that would have been incurred absent expense reimbursement or fee waiver arrangements. If the Fund has changed its fiscal year and, as a result, the most recent fiscal year is less than three months, use the fiscal year prior to the most recent fiscal year as the basis for determining "Annual Fund Operating Expenses."Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph d -Subsection instructions falsefalseTotal annual fund operating expenses0rr_ExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.01020.0102falsefalsefalsetruefalse3truetruetrue0.01020.0102falsefalsefalsetruefalseOthernanafalsefalseTotal annual fund operating expenses8falseRowprimaryElement*11false0rr_FeeWaiverOrReimbursementOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00000.0000[1]falsefalsefalsetruefalse3truetruetrue-0.0008-0.0008[1]falsefalsefalsetruefalseOtherrr:NonPositivePure4TypepureTotal Annual Fund Operating Expenses. If there were expense reimbursement or fee waiver arrangements that reduced any Fund operating expenses and will continue to reduce them for no less than one year from the effective date of the Fund's registration statement, a Fund may add two captions to the table one caption showing the amount of the expense reimbursement or fee waiver, and a second caption showing the Fund's net expenses after subtracting the fee reimbursement or expense waiver from the total fund operating expenses. The Fund should place these additional captions directly below the "Total Annual Fund Operating Expenses" caption of the table and should use appropriate descriptive captions, such as "Fee Waiver [and/or Expense Reimbursement]" and "Total Annual Fund Operating Expenses After Fee Waiver [and/or Expense Reimbursement]," respectively. If the Fund provides this disclosure, also disclose the period for which the expense reimbursement or fee waiver arrangement is expected to continue, and briefly describe who can terminate the arrangement and under what circumstances.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseLess: Fee waiver/expense reimbursement0rr_FeeWaiverOrReimbursementOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00000.0000falsefalsefalsetruefalse3truetruetrue-0.0008-0.0008falsefalsefalsetruefalseOthernanafalsefalseLess: Fee waiver/expense reimbursement9falseRowprimaryElement*12false0rr_NetExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.01020.0102[1]falsefalsefalsetruefalse3truetruetrue0.00940.0094[1]falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table truefalseTotal annual fund and acquired fund fees and expenses after fee waiver/expense reimbursement0rr_NetExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.01020.0102falsefalsefalsetruefalse3truetruetrue0.00940.0094falsefalsefalsetruefalseOthernanafalsefalseTotal annual fund and acquired fund fees and expenses after fee waiver/expense reimbursement1The investment manager and its affiliates have contractually agreed to waive certain fees and to reimburse certain expenses for all share classes until at least April 30, 2012, unless sooner terminated at the sole discretion of the Fund's Board. Any amounts waived will not be reimbursed by the Fund. Under this agreement, net fund expenses (including fees and expenses of acquired funds) will not exceed 0.94% for Class 4 shares of the Fund through April 30, 2012, unless sooner terminated at the sole discretion of the Fund's Board. 39Annual Fund Operating Expenses UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to OperatingExpensesData.No authoritative reference available.falsefalseAnnual Fund Operating Expenses [Table]49false0rr_ExpenseExampleHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00ExamplefalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringHeading for Expense Example.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseExpense Example [Heading]50false0rr_ExpenseExampleNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The 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 a subaccount that invests in the Fund for the time periods indicated and then redeem all of your investment 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. The Example includes contractual commitments to waive fees and reimburse expenses, if any, expiring as indicated in the preceding table. 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The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalseExpense Example, By Year, Column [Text]falseUSDfalsefalse$2falseColumnprimaryElement*5false0rr_ExpenseExampleYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue104104falsefalsefalsetruefalse2truefalsetrue9696falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalse1 yearfalseUSDfalsefalse$3falseColumnprimaryElement*6false0rr_ExpenseExampleYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue325325falsefalsefalsetruefalse2truefalsetrue309309falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse3 yearsfalseUSDfalsefalse$4falseColumnprimaryElement*7false0rr_ExpenseExampleYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue565565falsefalsefalsetruefalse2truefalsetrue549549falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse5 yearsfalseUSDfalsefalse$5falseColumnprimaryElement*8false0rr_ExpenseExampleYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue12541254falsefalsefalsetruefalse2truefalsetrue12391239falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse10 yearsfalseUSDfalsefalse$1falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-01T00:00:002011-04-29T00:00:00falsefalseVariable Portfolio - Moderate Portfoliodei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_S000028702Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass 2, VP - Moderate Portfoliorr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_C000087822Memberrr_ProspectusShareClassAxisexplicitMemberVariable Portfolio - Moderate PortfolioClass 2, VP - Moderate PortfolioUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class 2Class 2falsefalsefalsetruefalse2truefalsetrue104104falsefalsefalsetruefalse3truefalsetrue325325falsefalsefalsetruefalse4truefalsetrue565565falsefalsefalsetruefalse5truefalsetrue12541254falsefalsefalsetruefalseOthernanafalsefalseClass 2, VP - Moderate Portfolio2falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-01T00:00:002011-04-29T00:00:00falsefalseVariable Portfolio - Moderate Portfoliodei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_S000028702Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass 4, VP - Moderate Portfoliorr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_C000087823Memberrr_ProspectusShareClassAxisexplicitMemberVariable Portfolio - Moderate PortfolioClass 4, VP - Moderate PortfolioUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class 4Class 4falsefalsefalsetruefalse2truefalsetrue9696falsefalsefalsetruefalse3truefalsetrue309309falsefalsefalsetruefalse4truefalsetrue549549falsefalsefalsetruefalse5truefalsetrue12391239falsefalsefalsetruefalseOthernanafalsefalseClass 4, VP - Moderate Portfolio52Expense Example Variable Portfolio - Moderate Portfolio (USD $)UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ExpenseExample.No authoritative reference available.falsefalseExpense Example, With Redemption [Table]52false0rr_ExpenseExampleClosingTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This Example does not reflect the charges or expenses that apply to the subaccounts or the contracts. If such charges or expenses had been included, your costs set forth above would have been higher.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThe Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseExpense Example Closing [Text Block]53false0rr_PortfolioTurnoverHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Portfolio TurnoverfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 5 -Subsection instructions falsefalsePortfolio Turnover [Heading]54false0rr_PortfolioTurnoverTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund will indirectly bear the expenses associated with portfolio turnover of the underlying funds. The underlying funds pay transaction costs, such as commissions, when they buy and sell securities (or “turn over” their portfolio). An underlying fund’s higher portfolio turnover rate may indicate higher transaction costs. 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 20% of the average value of its portfolio.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subsection example falsefalsePortfolio Turnover [Text Block]55false0rr_StrategyHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PRINCIPAL INVESTMENT STRATEGIES OF THE FUNDfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy [Heading]56false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund is a “fund of funds” and seeks to achieve its objective by investing in a combination of underlying funds representing three primary asset classes: equity, fixed income and cash. The Fund may invest in derivatives such as index futures, Treasury futures, currency forwards, index-based total return swaps and indexed-based credit default swaps. Under normal market conditions, the Fund intends to invest in each asset class within the following target asset allocation ranges:</p><div style="font-face: times new roman; font-size:10pt" ><table style="font-size:10pt" cellpadding="0" cellspacing="0" border="0" width="100%"><tr><td width="30%"> </td><td width="10%"> </td><td width="20%"> </td><td width="20%"> </td><td width="20%"> </td></tr><tr><td > </td><td align="center"><b>Equity</b></td><td align="right"><b>Fixed Income</b></td><td align="center"><b>Cash</b></td><td > </td></tr><tr style="font-size:2pt"><td colspan="5"> </td></tr><tr><td > </td><td align="center">45-55%</td><td align="right">45-55%</td><td align="center">0-5%</td><td > </td></tr></table></div><p>Market appreciation or depreciation may cause the Fund to be temporarily outside the range identified in the table. The investment manager may modify the target allocation ranges only upon approval of the Fund’s Board of Trustees (the Board).</p><p>In selecting the proportion of the Fund’s assets to be invested within and across each of the three primary asset classes, the investment manager considers the independent analysis of Morningstar Associates (Morningstar), an independent investment consultant, on a broad range of aspects related to the management of the Fund including, but not limited to, the Fund’s asset allocation targets, the performance of the underlying funds, the types of investment categories represented by the underlying funds, and the consideration of additional underlying funds. The investment manager retains full discretion over the Fund’s investment activities. The Fund may also invest in derivative instruments to achieve its objective.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy Narrative [Text Block]57false0rr_RiskHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PRINCIPAL RISKS OF INVESTING IN THE FUNDfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subsection b falsefalseRisk [Heading]58false0rr_RiskNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>Please remember that with any mutual fund investment you may lose money. Principal risks associated with an investment in the Fund include specific risks relating to the investment in the Fund based on its investment process, and certain general risks based on its “funds of funds” structure. These risks are identified below.</p><p><b>Affiliated Fund Risk.</b> The risk that the investment manager may have potential conflicts of interest in selecting underlying funds because the fees paid to it by some underlying funds are higher than the fees paid by other underlying funds.</p><p><b> Active Management/Allocation Risk.</b> The risk that the investment manager’s evaluations regarding asset classes or underlying funds and the Fund’s allocations thereto may be incorrect. The ability of the Fund to realize its investment objective will depend, in part, on the extent to which the underlying funds realize their investment objectives. There is no guarantee that the underlying funds will achieve their investment objectives. The Fund is exposed to the same risks as the underlying funds in direct proportion to the allocation of its assets among the underlying funds.</p><p><b> Derivatives Risk.</b> Losses involving derivative instruments may be substantial, because a relatively small price movement in the underlying security(ies), instrument, currency or index may result in a substantial loss for the Fund. In addition to the potential for increased losses, the use of derivative instruments may lead to increased volatility within the Fund. Derivatives will typically increase the Fund’s exposure to principal risks to which it is otherwise exposed, and may expose the Fund to additional risks, including leverage risk, hedging risk, correlation risk, and liquidity risk.</p><p><b> Risks of Underlying Funds.</b> By investing in a combination of underlying funds, the Fund has exposure to the risks associated with many areas of the market. Since Moderate Portfolio intends to invest its assets in a balance of equity and fixed income asset classes, the Fund may have higher exposure to the following principal risks of the underlying funds: Active Management risk, Counterparty Risk, Credit Risk, Derivatives Risk, Interest Rate Risk, Issuer Risk, Market Risk, Prepayment and Extension Risk and Small and Mid-Sized Company Risk. Also, in addition to the Fund’s operating expenses, you will indirectly bear the operating expenses of the underlying funds. Thus, the expenses you bear as an investor in the Fund will be higher than if you invested directly in the underlying funds. A description of the more common principal risks to which the underlying funds (and thus, the Fund) are subject to are identified under “More Information about the Funds — Principal Risks of Investing in the Funds — Certain Principal Risks of the Underlying Funds.” A more complete list of principal risks associated with direct investment in the underlying funds is set forth in Appendix B. Additional risks of the underlying funds are set forth in the SAI.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringNarrative Risk Disclosure. A Fund may, in responding to this Item, describe the types of investors for whom the Fund is intended or the types of investment goals that may be consistent with an investment in the Fund.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subparagraph i -Clause instruction -Subsection b falsefalseRisk Narrative [Text Block]59false0rr_BarChartAndPerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PAST PERFORMANCEfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart and Performance Table [Heading]60false0rr_PerformanceNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The bar chart and past performance table are not presented because the Fund has not had a full calendar year of operations. The Fund began operations on May 7, 2010. When performance is available, Moderate Portfolio intends to compare its performance to the Barclays Capital U.S. Aggregate Bond Index and a Blended Index, consisting of 50% Barclays Capital U.S. Aggregate Bond Index, 35% Russell 3000 Index and 15% Morgan Stanley Capital International (MSCI) All Country World Index (ACWI) ex-US.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalsePerformance Narrative [Text Block]61false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://columbiamanagement.com/role/riskreturnsummaryvariableportfolio1falsefalsefalse00Variable Portfolio - Moderately Aggressive PortfolioVariable Portfolio - Moderately Aggressive Portfoliofalsefalsefalsefalsefalse4falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : Variable Portfolio - Moderately Aggressive Portfolio 5/1/2010 - 4/29/2011 TwelveMonthsEnded_29Apr2011_S000028694_Memberhttp://www.sec.gov/CIK0001413032duration2010-05-01T00:00:002011-04-29T00:00:00falsefalsecfvst1413032_S000028694Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_S000028694Memberdei_DocumentInformationDocumentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0OthernaNo definition available.No authoritative reference available.falsefalseVariable Portfolio - Moderately Aggressive Portfolio63false0rr_RiskReturnHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Summary of Variable Portfolio – Moderately Aggressive Portfolio (Moderately Aggressive Portfolio)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicatedReference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 falsefalseRisk/Return [Heading]64false0rr_ObjectiveHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00INVESTMENT OBJECTIVEfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseObjective [Heading]65false0rr_ObjectivePrimaryTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund seeks to provide a high level of total return that is consistent with a moderately aggressive level of risk.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseObjective, Primary [Text Block]66false0rr_ExpenseHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00FEES AND EXPENSES OF THE FUNDfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Summary Fee Table Includes the following information, in plain English under rule 421(d) under the Securities Act, after Item 2 Fees and expenses of the Fund This table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Shareholder Fees (fees paid directly from your investment) Example 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 you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be You would pay the following expenses if you did not redeem your shares The Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher. Portfolio Turnover The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover may indicate higher transaction costs. 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 __% of the average value of its whole portfolio. Instructions. A.3.instructions.6 New Funds. For purposes of this Item, a "New Fund" is a Fund that does not include in Form N-1A financial statements reporting operating results or that includes financial statements for the Fund's initial fiscal year reporting operating results for a period of 6 months or less. The following Instructions apply to New Funds.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph d -Subsection instructions falsefalseExpense [Heading]67false0rr_ExpenseNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This table describes the Fund’s fees and expenses that you may pay if you buy a variable annuity or life insurance policy and allocate your purchase payments or premiums to subaccounts that invest in the Fund. The table does not reflect any charges or expenses imposed by insurance companies on subaccounts or contracts. If such sales charges or expenses had been included, the expenses set forth below would be higher. In addition to the total annual Fund operating expenses that the Fund bears directly, the Fund’s shareholders indirectly bear the expenses of the underlying funds (or acquired funds) in which the Fund invests. The Fund’s “Acquired fund fees and expenses,” based on its allocations to the underlying funds, is as shown. Because acquired funds will have varied expense and fee levels and the Fund may own different proportions of acquired funds at different times, the amount of fees and expenses incurred by the Fund with respect to such investments will vary.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThis table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Include the narrative explanations in the order indicated. A Fund may modify the narrative explanations if the explanation contains comparable information to that shown.The narrative explanation regarding sales charge discounts is only required by a Fund that offers such discounts and should specify the minimum level of investment required to qualify for a discount. Modify the narrative explanation to state that Fund shares are sold on a national securities exchange at the end of the time periods indicated, and that brokerage commissions for buying and selling Fund shares through a broker are not reflected.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph b -Subsection instructions falsefalseExpense Narrative [Text Block]68false0rr_AnnualFundOperatingExpensesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> <div style="display:none;">~ http://columbiamanagement.com/role/AnnualFundOperatingExpensesVariablePortfolioModeratelyAggressivePortfolio column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfvst1413032_S000028694_Member * row dei_LegalEntityAxis compact cfvst1413032_S000028694_Member * ~</div> </div>falsefalse<div> <div style="display:none;">~ http://columbiamanagement.com/role/AnnualFundOperatingExpensesVariablePortfolioModeratelyAggressivePortfolio column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfvst1413032_S000028694_Member * row dei_LegalEntityAxis compact cfvst1413032_S000028694_Member * ~</div> </div>falsehttp://columbiamanagement.com/role/AnnualFundOperatingExpensesVariablePortfolioModeratelyAggressivePortfoliofalsefalse0200245 - 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Under an appropriate caption or a subcaption of "Other Expenses," disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 9 -Subsection table falsefalseDistribution and/or service (12b-1) fees0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00250.0025falsefalsefalsetruefalse3truetruetrue0.00250.0025falsefalsefalsetruefalseOthernanafalsefalseDistribution and/or service (12b-1) fees5falseRowprimaryElement*8false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00020.0002falsefalsefalsetruefalse3truetruetrue0.00020.0002falsefalsefalsetruefalseOtherrr:NonNegativePure4Typepure"Other Expenses" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]). "Other Expenses" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's "Other Expenses," disclose in a footnote to the table what "Other Expenses" would have been had the extraordinary expenses been included.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph c -Clause i -Subsection instructions falsefalseOther expenses0rr_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00020.0002falsefalsefalsetruefalse3truetruetrue0.00020.0002falsefalsefalsetruefalseOthernanafalsefalseOther expenses6falseRowprimaryElement*9false0rr_AcquiredFundFeesAndExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00790.0079falsefalsefalsetruefalse3truetruetrue0.00790.0079falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseAcquired Fund Fees and Expenses0rr_AcquiredFundFeesAndExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00790.0079falsefalsefalsetruefalse3truetruetrue0.00790.0079falsefalsefalsetruefalseOthernanafalsefalseAcquired Fund Fees and Expenses7falseRowprimaryElement*10false0rr_ExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.01060.0106falsefalsefalsetruefalse3truetruetrue0.01060.0106falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses. If the Fund is a Feeder Fund, reflect the aggregate expenses of the Feeder Fund and the Master Fund in a single fee table using the captions provided. In a footnote to the fee table, state that the table and Example reflect the expenses of both the Feeder and Master Funds. If the prospectus offers more than one Class of a Multiple Class Fund or more than one Feeder Fund that invests in the same Master Fund, provide a separate response for each Class or Feeder Fund. Base the percentages of "Annual Fund Operating Expenses" on amounts incurred during the Fund's most recent fiscal year, but include in expenses amounts that would have been incurred absent expense reimbursement or fee waiver arrangements. If the Fund has changed its fiscal year and, as a result, the most recent fiscal year is less than three months, use the fiscal year prior to the most recent fiscal year as the basis for determining "Annual Fund Operating Expenses."Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph d -Subsection instructions falsefalseTotal annual fund operating expenses0rr_ExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.01060.0106falsefalsefalsetruefalse3truetruetrue0.01060.0106falsefalsefalsetruefalseOthernanafalsefalseTotal annual fund operating expenses8falseRowprimaryElement*11false0rr_FeeWaiverOrReimbursementOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00000.0000[1]falsefalsefalsetruefalse3truetruetrue-0.0008-0.0008[1]falsefalsefalsetruefalseOtherrr:NonPositivePure4TypepureTotal Annual Fund Operating Expenses. If there were expense reimbursement or fee waiver arrangements that reduced any Fund operating expenses and will continue to reduce them for no less than one year from the effective date of the Fund's registration statement, a Fund may add two captions to the table one caption showing the amount of the expense reimbursement or fee waiver, and a second caption showing the Fund's net expenses after subtracting the fee reimbursement or expense waiver from the total fund operating expenses. The Fund should place these additional captions directly below the "Total Annual Fund Operating Expenses" caption of the table and should use appropriate descriptive captions, such as "Fee Waiver [and/or Expense Reimbursement]" and "Total Annual Fund Operating Expenses After Fee Waiver [and/or Expense Reimbursement]," respectively. If the Fund provides this disclosure, also disclose the period for which the expense reimbursement or fee waiver arrangement is expected to continue, and briefly describe who can terminate the arrangement and under what circumstances.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseLess: Fee waiver/expense reimbursement0rr_FeeWaiverOrReimbursementOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00000.0000falsefalsefalsetruefalse3truetruetrue-0.0008-0.0008falsefalsefalsetruefalseOthernanafalsefalseLess: Fee waiver/expense reimbursement9falseRowprimaryElement*12false0rr_NetExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.01060.0106[1]falsefalsefalsetruefalse3truetruetrue0.00980.0098[1]falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table truefalseTotal annual fund and acquired fund fees and expenses after fee waiver/expense reimbursement0rr_NetExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.01060.0106falsefalsefalsetruefalse3truetruetrue0.00980.0098falsefalsefalsetruefalseOthernanafalsefalseTotal annual fund and acquired fund fees and expenses after fee waiver/expense reimbursement1The investment manager and its affiliates have contractually agreed to waive certain fees and to reimburse certain expenses for all share classes until at least April 30, 2012, unless sooner terminated at the sole discretion of the Fund's Board. 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Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalse1 yearfalseUSDfalsefalse$3falseColumnprimaryElement*6false0rr_ExpenseExampleYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue338338falsefalsefalsetruefalse2truefalsetrue322322falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse3 yearsfalseUSDfalsefalse$4falseColumnprimaryElement*7false0rr_ExpenseExampleYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue587587falsefalsefalsetruefalse2truefalsetrue571571falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse5 yearsfalseUSDfalsefalse$5falseColumnprimaryElement*8false0rr_ExpenseExampleYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue13011301falsefalsefalsetruefalse2truefalsetrue12861286falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. 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A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 5 -Subsection instructions falsefalsePortfolio Turnover [Heading]74false0rr_PortfolioTurnoverTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund will indirectly bear the expenses associated with portfolio turnover of the underlying funds. The underlying funds pay transaction costs, such as commissions, when they buy and sell securities (or “turn over” their portfolio). An underlying fund’s higher portfolio turnover rate may indicate higher transaction costs. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund’s performance. 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Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy [Heading]76false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund is a “fund of funds” and seeks to achieve its objective by investing in a combination of underlying funds representing three primary asset classes: equity, fixed income and cash. The Fund may invest in derivatives such as index futures, Treasury futures, currency forwards, index-based total return swaps and indexed-based credit default swaps. Under normal market conditions, the Fund intends to invest in each asset class within the following target asset allocation ranges:</p><div style="font-face: times new roman; font-size:10pt" ><table style="font-size:10pt" cellpadding="0" cellspacing="0" border="0" width="100%"><tr><td width="30%"> </td><td width="10%"> </td><td width="20%"> </td><td width="20%"> </td><td width="20%"> </td></tr><tr><td > </td><td align="center"><b>Equity</b></td><td align="right"><b>Fixed Income</b></td><td align="center"><b>Cash</b></td><td > </td></tr><tr style="font-size:2pt"><td colspan="5"> </td></tr><tr><td > </td><td align="center">60-70%</td><td align="right">30-40%</td><td align="center">0-5%</td><td > </td></tr></table></div><p>Market appreciation or depreciation may cause the Fund to be temporarily outside the range identified in the table. The investment manager may modify the target allocation ranges only upon approval of the Fund’s Board of Trustees (the Board).</p><p>In selecting the proportion of the Fund’s assets to be invested within and across each of the three primary asset classes, the investment manager considers the independent analysis of Morningstar Associates (Morningstar), an independent investment consultant, on a broad range of aspects related to the management of the Fund including, but not limited to, the Fund’s asset allocation targets, the performance of the underlying funds, the types of investment categories represented by the underlying funds, and the consideration of additional underlying funds. The investment manager retains full discretion over the Fund’s investment activities. The Fund may also invest in derivative instruments to achieve its objective.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy Narrative [Text Block]77false0rr_RiskHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PRINCIPAL RISKS OF INVESTING IN THE FUNDfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subsection b falsefalseRisk [Heading]78false0rr_RiskNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>Please remember that with any mutual fund investment you may lose money. Principal risks associated with an investment in the Fund include specific risks relating to the investment in the Fund based on its investment process, and certain general risks based on its “funds of funds” structure. These risks are identified below.</p><p><b>Affiliated Fund Risk.</b> The risk that the investment manager may have potential conflicts of interest in selecting underlying funds because the fees paid to it by some underlying funds are higher than the fees paid by other underlying funds.</p><p><b> Active Management/Allocation Risk.</b> The risk that the investment manager’s evaluations regarding asset classes or underlying funds and the Fund’s allocations thereto may be incorrect. The ability of the Fund to realize its investment objective will depend, in part, on the extent to which the underlying funds realize their investment objectives. There is no guarantee that the underlying funds will achieve their investment objectives. The Fund is exposed to the same risks as the underlying funds in direct proportion to the allocation of its assets among the underlying funds.</p><p><b> Derivatives Risk.</b> Losses involving derivative instruments may be substantial, because a relatively small price movement in the underlying security(ies), instrument, currency or index may result in a substantial loss for the Fund. In addition to the potential for increased losses, the use of derivative instruments may lead to increased volatility within the Fund. Derivatives will typically increase the Fund’s exposure to principal risks to which it is otherwise exposed, and may expose the Fund to additional risks, including leverage risk, hedging risk, correlation risk, and liquidity risk.</p><p><b> Risks of Underlying Funds.</b> By investing in a combination of underlying funds, the Fund has exposure to the risks associated with many areas of the market. Since Moderately Aggressive Portfolio intends to invest a significant portion of its assets in equity asset classes, the Fund may have higher exposure to the following principal risks of the underlying funds: Active Management risk, Derivatives Risk, Issuer Risk, Market Risk and Small and Mid-Sized Company Risk. Also, in addition to the Fund’s operating expenses, you will indirectly bear the operating expenses of the underlying funds. Thus, the expenses you bear as an investor in the Fund will be higher than if you invested directly in the underlying funds. A description of the more common principal risks to which the underlying funds (and thus, the Fund) are subject to are identified under “More Information about the Funds — Principal Risks of Investing in the Funds — Certain Principal Risks of the Underlying Funds.” A more complete list of principal risks associated with direct investment in the underlying funds is set forth in Appendix B. Additional risks of the underlying funds are set forth in the SAI.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringNarrative Risk Disclosure. A Fund may, in responding to this Item, describe the types of investors for whom the Fund is intended or the types of investment goals that may be consistent with an investment in the Fund.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subparagraph i -Clause instruction -Subsection b falsefalseRisk Narrative [Text Block]79false0rr_BarChartAndPerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PAST PERFORMANCEfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart and Performance Table [Heading]80false0rr_PerformanceNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The bar chart and past performance table are not presented because the Fund has not had a full calendar year of operations. The Fund began operations on May 7, 2010. When performance is available, Moderately Aggressive Portfolio intends to compare its performance to the Russell 3000 Index and a Blended Index, consisting of 45.5% Russell 3000 Index, 35% Barclays Capital U.S. Aggregate Bond Index and 19.5% Morgan Stanley Capital International (MSCI) All Country World Index (ACWI) ex-US.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalsePerformance Narrative [Text Block]81false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://columbiamanagement.com/role/riskreturnsummaryvariableportfolio1falsefalsefalse00Variable Portfolio - Aggressive PortfolioVariable Portfolio - Aggressive Portfoliofalsefalsefalsefalsefalse5falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : Variable Portfolio - Aggressive Portfolio 5/1/2010 - 4/29/2011 TwelveMonthsEnded_29Apr2011_S000028683_Memberhttp://www.sec.gov/CIK0001413032duration2010-05-01T00:00:002011-04-29T00:00:00falsefalsecfvst1413032_S000028683Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_S000028683Memberdei_DocumentInformationDocumentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0OthernaNo definition available.No authoritative reference available.falsefalseVariable Portfolio - Aggressive Portfolio83false0rr_RiskReturnHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Summary of Variable Portfolio – Aggressive Portfolio (Aggressive Portfolio)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicatedReference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 falsefalseRisk/Return [Heading]84false0rr_ObjectiveHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00INVESTMENT OBJECTIVEfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseObjective [Heading]85false0rr_ObjectivePrimaryTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund seeks to provide a high level of total return that is consistent with an aggressive level of risk.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. 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Shareholder Fees (fees paid directly from your investment) Example 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 you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be You would pay the following expenses if you did not redeem your shares The Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher. Portfolio Turnover The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover may indicate higher transaction costs. 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 __% of the average value of its whole portfolio. Instructions. A.3.instructions.6 New Funds. For purposes of this Item, a "New Fund" is a Fund that does not include in Form N-1A financial statements reporting operating results or that includes financial statements for the Fund's initial fiscal year reporting operating results for a period of 6 months or less. The following Instructions apply to New Funds.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph d -Subsection instructions falsefalseExpense [Heading]87false0rr_ExpenseNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This table describes the Fund’s fees and expenses that you may pay if you buy a variable annuity or life insurance policy and allocate your purchase payments or premiums to subaccounts that invest in the Fund. The table does not reflect any charges or expenses imposed by insurance companies on subaccounts or contracts. If such sales charges or expenses had been included, the expenses set forth below would be higher. In addition to the total annual Fund operating expenses that the Fund bears directly, the Fund’s shareholders indirectly bear the expenses of the underlying funds (or acquired funds) in which the Fund invests. The Fund’s “Acquired fund fees and expenses,” based on its allocations to the underlying funds, is as shown. Because acquired funds will have varied expense and fee levels and the Fund may own different proportions of acquired funds at different times, the amount of fees and expenses incurred by the Fund with respect to such investments will vary.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThis table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Include the narrative explanations in the order indicated. A Fund may modify the narrative explanations if the explanation contains comparable information to that shown.The narrative explanation regarding sales charge discounts is only required by a Fund that offers such discounts and should specify the minimum level of investment required to qualify for a discount. 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Under an appropriate caption or a subcaption of "Other Expenses," disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 9 -Subsection table falsefalseDistribution and/or service (12b-1) fees0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00250.0025falsefalsefalsetruefalse3truetruetrue0.00250.0025falsefalsefalsetruefalseOthernanafalsefalseDistribution and/or service (12b-1) fees5falseRowprimaryElement*8false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00020.0002falsefalsefalsetruefalse3truetruetrue0.00020.0002falsefalsefalsetruefalseOtherrr:NonNegativePure4Typepure"Other Expenses" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]). "Other Expenses" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's "Other Expenses," disclose in a footnote to the table what "Other Expenses" would have been had the extraordinary expenses been included.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph c -Clause i -Subsection instructions falsefalseOther expenses0rr_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00020.0002falsefalsefalsetruefalse3truetruetrue0.00020.0002falsefalsefalsetruefalseOthernanafalsefalseOther expenses6falseRowprimaryElement*9false0rr_AcquiredFundFeesAndExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00820.0082falsefalsefalsetruefalse3truetruetrue0.00820.0082falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseAcquired Fund Fees and Expenses0rr_AcquiredFundFeesAndExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00820.0082falsefalsefalsetruefalse3truetruetrue0.00820.0082falsefalsefalsetruefalseOthernanafalsefalseAcquired Fund Fees and Expenses7falseRowprimaryElement*10false0rr_ExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.01090.0109falsefalsefalsetruefalse3truetruetrue0.01090.0109falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses. If the Fund is a Feeder Fund, reflect the aggregate expenses of the Feeder Fund and the Master Fund in a single fee table using the captions provided. In a footnote to the fee table, state that the table and Example reflect the expenses of both the Feeder and Master Funds. If the prospectus offers more than one Class of a Multiple Class Fund or more than one Feeder Fund that invests in the same Master Fund, provide a separate response for each Class or Feeder Fund. Base the percentages of "Annual Fund Operating Expenses" on amounts incurred during the Fund's most recent fiscal year, but include in expenses amounts that would have been incurred absent expense reimbursement or fee waiver arrangements. 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If there were expense reimbursement or fee waiver arrangements that reduced any Fund operating expenses and will continue to reduce them for no less than one year from the effective date of the Fund's registration statement, a Fund may add two captions to the table one caption showing the amount of the expense reimbursement or fee waiver, and a second caption showing the Fund's net expenses after subtracting the fee reimbursement or expense waiver from the total fund operating expenses. The Fund should place these additional captions directly below the "Total Annual Fund Operating Expenses" caption of the table and should use appropriate descriptive captions, such as "Fee Waiver [and/or Expense Reimbursement]" and "Total Annual Fund Operating Expenses After Fee Waiver [and/or Expense Reimbursement]," respectively. If the Fund provides this disclosure, also disclose the period for which the expense reimbursement or fee waiver arrangement is expected to continue, and briefly describe who can terminate the arrangement and under what circumstances.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseLess: Fee waiver/expense reimbursement0rr_FeeWaiverOrReimbursementOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00000.0000falsefalsefalsetruefalse3truetruetrue-0.001-0.001falsefalsefalsetruefalseOthernanafalsefalseLess: Fee waiver/expense reimbursement9falseRowprimaryElement*12false0rr_NetExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.01090.0109[1]falsefalsefalsetruefalse3truetruetrue0.00990.0099[1]falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table truefalseTotal annual fund and acquired fund fees and expenses after fee waiver/expense reimbursement0rr_NetExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.01090.0109falsefalsefalsetruefalse3truetruetrue0.00990.0099falsefalsefalsetruefalseOthernanafalsefalseTotal annual fund and acquired fund fees and expenses after fee waiver/expense reimbursement1The investment manager and its affiliates have contractually agreed to waive certain fees and to reimburse certain expenses for all share classes until at least April 30, 2012, unless sooner terminated at the sole discretion of the Fund's Board. Any amounts waived will not be reimbursed by the Fund. Under this agreement, net fund expenses (including fees and expenses of acquired funds) will not exceed 0.99% for Class 4 shares of the Fund through April 30, 2012, unless sooner terminated at the sole discretion of the Fund's Board. 39Annual Fund Operating Expenses UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to OperatingExpensesData.No authoritative reference available.falsefalseAnnual Fund Operating Expenses [Table]89false0rr_ExpenseExampleHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00ExamplefalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringHeading for Expense Example.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseExpense Example [Heading]90false0rr_ExpenseExampleNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The 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 a subaccount that invests in the Fund for the time periods indicated and then redeem all of your investment 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. The Example includes contractual commitments to waive fees and reimburse expenses, if any, expiring as indicated in the preceding table. 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The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalseExpense Example, By Year, Column [Text]falseUSDfalsefalse$2falseColumnprimaryElement*5false0rr_ExpenseExampleYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue112112falsefalsefalsetruefalse2truefalsetrue101101falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalse1 yearfalseUSDfalsefalse$3falseColumnprimaryElement*6false0rr_ExpenseExampleYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue348348falsefalsefalsetruefalse2truefalsetrue328328falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse3 yearsfalseUSDfalsefalse$4falseColumnprimaryElement*7false0rr_ExpenseExampleYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue604604falsefalsefalsetruefalse2truefalsetrue584584falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse5 yearsfalseUSDfalsefalse$5falseColumnprimaryElement*8false0rr_ExpenseExampleYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue13381338falsefalsefalsetruefalse2truefalsetrue13201320falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse10 yearsfalseUSDfalsefalse$1falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-01T00:00:002011-04-29T00:00:00falsefalseVariable Portfolio - Aggressive Portfoliodei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_S000028683Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass 2, VP - Aggressive Portfoliorr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_C000087784Memberrr_ProspectusShareClassAxisexplicitMemberVariable Portfolio - Aggressive PortfolioClass 2, VP - Aggressive PortfolioUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class 2Class 2falsefalsefalsetruefalse2truefalsetrue112112falsefalsefalsetruefalse3truefalsetrue348348falsefalsefalsetruefalse4truefalsetrue604604falsefalsefalsetruefalse5truefalsetrue13381338falsefalsefalsetruefalseOthernanafalsefalseClass 2, VP - Aggressive Portfolio2falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-01T00:00:002011-04-29T00:00:00falsefalseVariable Portfolio - Aggressive Portfoliodei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_S000028683Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass 4, VP - Aggressive Portfoliorr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfvst1413032_C000087785Memberrr_ProspectusShareClassAxisexplicitMemberVariable Portfolio - Aggressive PortfolioClass 4, VP - Aggressive PortfolioUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class 4Class 4falsefalsefalsetruefalse2truefalsetrue101101falsefalsefalsetruefalse3truefalsetrue328328falsefalsefalsetruefalse4truefalsetrue584584falsefalsefalsetruefalse5truefalsetrue13201320falsefalsefalsetruefalseOthernanafalsefalseClass 4, VP - Aggressive Portfolio52Expense Example Variable Portfolio - Aggressive Portfolio (USD $)UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ExpenseExample.No authoritative reference available.falsefalseExpense Example, With Redemption [Table]92false0rr_ExpenseExampleClosingTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This Example does not reflect the charges or expenses that apply to the subaccounts or the contracts. If such charges or expenses had been included, your costs set forth above would have been higher.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThe Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseExpense Example Closing [Text Block]93false0rr_PortfolioTurnoverHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Portfolio TurnoverfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 5 -Subsection instructions falsefalsePortfolio Turnover [Heading]94false0rr_PortfolioTurnoverTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund will indirectly bear the expenses associated with portfolio turnover of the underlying funds. The underlying funds pay transaction costs, such as commissions, when they buy and sell securities (or “turn over” their portfolio). An underlying fund’s higher portfolio turnover rate may indicate higher transaction costs. 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 20% of the average value of its portfolio.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subsection example falsefalsePortfolio Turnover [Text Block]95false0rr_StrategyHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PRINCIPAL INVESTMENT STRATEGIES OF THE FUNDfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy [Heading]96false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund is a “fund of funds” and seeks to achieve its objective by investing in a combination of underlying funds representing three primary asset classes: equity, fixed income and cash. The Fund may invest in derivatives such as index futures, Treasury futures, currency forwards, index-based total return swaps and indexed-based credit default swaps. Under normal market conditions, the Fund intends to invest in each asset class within the following target asset allocation ranges:</p><div style="font-face: times new roman; font-size:10pt" ><table style="font-size:10pt" cellpadding="0" cellspacing="0" border="0" width="100%"><tr><td width="30%"> </td><td width="10%"> </td><td width="20%"> </td><td width="20%"> </td><td width="20%"> </td></tr><tr><td > </td><td align="center"><b>Equity</b></td><td align="right"><b>Fixed Income</b></td><td align="center"><b>Cash</b></td><td > </td></tr><tr style="font-size:2pt"><td colspan="5"> </td></tr><tr><td > </td><td align="center">75-85%</td><td align="right">15-25%</td><td align="center">0-5%</td><td > </td></tr></table></div><p>Market appreciation or depreciation may cause the Fund to be temporarily outside the range identified in the table. The investment manager may modify the target allocation ranges only upon approval of the Fund’s Board of Trustees (the Board).</p><p>In selecting the proportion of the Fund’s assets to be invested within and across each of the three primary asset classes, the investment manager considers the independent analysis of Morningstar Associates (Morningstar), an independent investment consultant, on a broad range of aspects related to the management of the Fund including, but not limited to, the Fund’s asset allocation targets, the performance of the underlying funds, the types of investment categories represented by the underlying funds, and the consideration of additional underlying funds. The investment manager retains full discretion over the Fund’s investment activities. The Fund may also invest in derivative instruments to achieve its objective.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy Narrative [Text Block]97false0rr_RiskHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PRINCIPAL RISKS OF INVESTING IN THE FUNDfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subsection b falsefalseRisk [Heading]98false0rr_RiskNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>Please remember that with any mutual fund investment you may lose money. Principal risks associated with an investment in the Fund include specific risks relating to the investment in the Fund based on its investment process, and certain general risks based on its “funds of funds” structure. These risks are identified below.</p><p><b>Affiliated Fund Risk.</b> The risk that the investment manager may have potential conflicts of interest in selecting underlying funds because the fees paid to it by some underlying funds are higher than the fees paid by other underlying funds.</p><p><b> Active Management/Allocation Risk.</b> The risk that the investment manager’s evaluations regarding asset classes or underlying funds and the Fund’s allocations thereto may be incorrect. The ability of the Fund to realize its investment objective will depend, in part, on the extent to which the underlying funds realize their investment objectives. There is no guarantee that the underlying funds will achieve their investment objectives. The Fund is exposed to the same risks as the underlying funds in direct proportion to the allocation of its assets among the underlying funds.</p><p><b>Derivatives Risk.</b> Losses involving derivative instruments may be substantial, because a relatively small price movement in the underlying security(ies), instrument, currency or index may result in a substantial loss for the Fund. In addition to the potential for increased losses, the use of derivative instruments may lead to increased volatility within the Fund. Derivatives will typically increase the Fund’s exposure to principal risks to which it is otherwise exposed, and may expose the Fund to additional risks, including leverage risk, hedging risk, correlation risk, and liquidity risk.</p><p><b>Risks of Underlying Funds.</b> By investing in a combination of underlying funds, the Fund has exposure to the risks associated with many areas of the market. Since Aggressive Portfolio intends to invest a significant portion of its assets in equity asset classes, the Fund may have higher exposure to the following principal risks of the underlying funds: Active Management risk, Derivatives Risk, Market Risk and Small and Mid-Sized Company Risk. Also, in addition to the Fund’s operating expenses, you will indirectly bear the operating expenses of the underlying funds. Thus, the expenses you bear as an investor in the Fund will be higher than if you invested directly in the underlying funds. A description of the more common principal risks to which the underlying funds (and thus, the Fund) are subject to are identified under “More Information about the Funds — Principal Risks of Investing in the Funds — Certain Principal Risks of the Underlying Funds.” A more complete list of principal risks associated with direct investment in the underlying funds is set forth in Appendix B. Additional risks of the underlying funds are set forth in the SAI.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringNarrative Risk Disclosure. A Fund may, in responding to this Item, describe the types of investors for whom the Fund is intended or the types of investment goals that may be consistent with an investment in the Fund.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subparagraph i -Clause instruction -Subsection b falsefalseRisk Narrative [Text Block]99false0rr_BarChartAndPerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PAST PERFORMANCEfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart and Performance Table [Heading]100false0rr_PerformanceNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The bar chart and past performance table are not presented because the Fund has not had a full calendar year of operations. The Fund began operations on May 7, 2010. When performance is available, Aggressive Portfolio intends to compare its performance to the Russell 3000 Index and a Blended Index, consisting of 56% Russell 3000 Index, 24% Morgan Stanley Capital International (MSCI) All Country World Index (ACWI) ex-US and 20% Barclays Capital U.S. Aggregate Bond Index.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalsePerformance Narrative [Text Block]195Risk/Return Summary - Variable Portfolio -UnKnownUnKnownUnKnownUnKnownfalsetrue