2.2.0.25truefalse010005 - Document - Risk/Return Summary - Columbia U.S. Government Mortgage Fund (Class Z Shares) {Unlabeled}falsefalsetrue1falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : Columbia U.S. Government Mortgage Fund {dei_LegalEntityAxis} : Class Z Shares 2/19/2010 - 2/18/2011 TwelveMonthsEnded_18Feb2011_S000031344_Member_Prospectus_One_Memberhttp://www.sec.gov/CIK0001352280duration2010-02-19T00:00:002011-02-18T00:00:00falsefalsecfst1352280_S000031344Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_S000031344Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalsecfst1352280_ProspectusOneMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_ProspectusOneMemberdei_LegalEntityAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli01false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://columbiamanagement.com/role/riskreturnsummarycolumbiausgovernmentmortgagefundclasszshares1falsefalsefalse00Columbia U.S. Government Mortgage Fund | Class Z SharesColumbia U.S. Government Mortgage Fund | Class Z Sharesfalsefalsefalsefalsefalse1falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : Columbia U.S. Government Mortgage Fund {dei_LegalEntityAxis} : Class Z Shares 2/19/2010 - 2/18/2011 TwelveMonthsEnded_18Feb2011_S000031344_Member_Prospectus_One_Memberhttp://www.sec.gov/CIK0001352280duration2010-02-19T00:00:002011-02-18T00:00:00falsefalsecfst1352280_S000031344Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_S000031344Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalsecfst1352280_ProspectusOneMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_ProspectusOneMemberdei_LegalEntityAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0OthernaNo definition available.No authoritative reference available.falsefalse3false0rr_RiskReturnHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Summary of the FundfalsefalsefalsefalsefalseOtherxbrli: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 falsefalse4false0rr_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 falsefalse5false0rr_ObjectivePrimaryTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Columbia U.S. Government Mortgage Fund (the Fund) seeks to provide shareholders with current income as its primary objective and, as its secondary objective, preservation of capital.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 falsefalse6false0rr_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 falsefalse7false0rr_ExpenseNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This table describes the fees and expenses that you may pay if you buy and hold Class Z shares of the Fund.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 falsefalse8false0rr_ShareholderFeesCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Shareholder Fees (fees paid directly from your investment)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringShareholder Fees (fees paid directly from your investment).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subsection table falsefalse9false0rr_ShareholderFeesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://columbiamanagement.com/role/ShareholderFeesColumbiaUSGovernmentMortgageFundClassZShares column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfst1352280_S000031344_Member * row dei_LegalEntityAxis compact cfst1352280_Prospectus_One_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;"&gt;~ http://columbiamanagement.com/role/ShareholderFeesColumbiaUSGovernmentMortgageFundClassZShares column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfst1352280_S000031344_Member * row dei_LegalEntityAxis compact cfst1352280_Prospectus_One_Member * ~&lt;/div&gt; </div>falsehttp://columbiamanagement.com/role/ShareholderFeesColumbiaUSGovernmentMortgageFundClassZSharesfalsefalse0200106 - Schedule - Shareholder Fees - Columbia U.S. Government Mortgage Fund (Class Z Shares)truefalsefalse1falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2010-02-19T00:00:002011-02-18T00:00:00falsefalseColumbia U.S. Government Mortgage Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_S000031344Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass Z Sharesdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_ProspectusOneMemberdei_LegalEntityAxisexplicitMemberfalsefalseColumbia U.S. Government Mortgage Fund - Class Zrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_C000097361Memberrr_ProspectusShareClassAxisexplicitMemberColumbia U.S. Government Mortgage FundClass Z SharesColumbia U.S. Government Mortgage Fund - Class ZUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*4false0rr_ShareholderFeesColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class ZfalsefalsefalsetruefalseOtherus-types:textBlockItemTypestringShareholder Fees (fees paid directly from your investment).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subsection table falsefalse0rr_ShareholderFeesColumnNametruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class ZClass ZfalsefalsefalsetruefalseOthernanafalsefalse2falseRowprimaryElement*5false0rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPricerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00000.0000falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureMaximum Deferred Sales Charge (Load) (as a percentage of ____) A.3.instructions.2.a.i "Maximum Deferred Sales Charge (Load)" includes the maximum total deferred sales charge (load) payable upon redemption, in installments, or both, expressed as a percentage of the amount or amounts stated in response to Item 7(a), except that, for a sales charge (load) based on net asset value at the time of purchase, show the sales charge (load) as a percentage of the offering price at the time of purchase. A Fund may include in a footnote to the table, if applicable, a tabular presentation showing the amount of deferred sales charges (loads) over time or a narrative explanation of the sales charges (loads) (e.g., __% in the first year after purchase, declining to __% in the __ year and eliminated thereafter). A.3.instructions.2.a.ii If more than one type of sales charge (load) is imposed (e.g., a deferred sales charge (load) and a front-end sales charge (load)), the first caption in the table should read "Maximum Sales Charge (Load)" and show the maximum cumulative percentage. Show the percentage amounts and the terms of each sales charge (load) comprising that figure on separate lines below.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection table falsefalse0rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPricetruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalse3falseRowprimaryElement*6false0rr_MaximumDeferredSalesChargeOverOtherrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00000.0000falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureMaximum Deferred Sales Charge (Load) (as a percentage of ____) "Maximum Deferred Sales Charge (Load)" includes the maximum total deferred sales charge (load) payable upon redemption, in installments, or both, expressed as a percentage of the amount or amounts stated in response to Item 7(a), except that, for a sales charge (load) based on net asset value at the time of purchase, show the sales charge (load) as a percentage of the offering price at the time of purchase. A Fund may include in a footnote to the table, if applicable, a tabular presentation showing the amount of deferred sales charges (loads) over time or a narrative explanation of the sales charges (loads) (e.g., __% in the first year after purchase, declining to __% in the __ year and eliminated thereafter). If more than one type of sales charge (load) is imposed (e.g., a deferred sales charge (load) and a front-end sales charge (load)), the first caption in the table should read "Maximum Sales Charge (Load)" and show the maximum cumulative percentage. Show the percentage amounts and the terms of each sales charge (load) comprising that figure on separate lines below.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 2 -Subparagraph a -Clause i -Subsection instructions falsefalse0rr_MaximumDeferredSalesChargeOverOthertruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalse13Shareholder Fees - Columbia U.S. Government Mortgage Fund (Class Z Shares) UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ShareholderFeesData.No authoritative reference available.falsefalse10false0rr_OperatingExpensesCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringAnnual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investment)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 7 -Subsection table falsefalse11false0rr_AnnualFundOperatingExpensesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://columbiamanagement.com/role/AnnualFundOperatingExpensesColumbiaUSGovernmentMortgageFundClassZShares column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfst1352280_S000031344_Member * row dei_LegalEntityAxis compact cfst1352280_Prospectus_One_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;"&gt;~ http://columbiamanagement.com/role/AnnualFundOperatingExpensesColumbiaUSGovernmentMortgageFundClassZShares column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfst1352280_S000031344_Member * row dei_LegalEntityAxis compact cfst1352280_Prospectus_One_Member * ~&lt;/div&gt; </div>falsehttp://columbiamanagement.com/role/AnnualFundOperatingExpensesColumbiaUSGovernmentMortgageFundClassZSharesfalsefalse0200206 - Schedule - Annual Fund Operating Expenses - Columbia U.S. Government Mortgage Fund (Class Z Shares)truefalsefalse1falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2010-02-19T00:00:002011-02-18T00:00:00falsefalseColumbia U.S. Government Mortgage Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_S000031344Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass Z Sharesdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_ProspectusOneMemberdei_LegalEntityAxisexplicitMemberfalsefalseColumbia U.S. Government Mortgage Fund - Class Zrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_C000097361Memberrr_ProspectusShareClassAxisexplicitMemberColumbia U.S. Government Mortgage FundClass Z SharesColumbia U.S. Government Mortgage Fund - Class ZUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*4false0rr_OperatingExpensesColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class ZfalsefalsefalsetruefalseOtherus-types:textBlockItemTypestringAnnual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investment)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 7 -Subsection table falsefalse0rr_OperatingExpensesColumnNametruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class ZClass ZfalsefalsefalsetruefalseOthernanafalsefalse2falseRowprimaryElement*5false0rr_ManagementFeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00480.0048falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureManagement Fees include investment advisory fees (including any fees based on the Fund's performance), any other management fees payable to the investment adviser or its affiliates, and administrative fees payable to the investment adviser or its affiliates that are not included as "Other Expenses."Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph a -Subsection instructions falsefalse0rr_ManagementFeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00480.0048falsefalsefalsetruefalseOthernanafalsefalse3falseRowprimaryElement*6false0rr_DistributionAndService12b1FeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00000.0000falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureDistribution [and/or Service] (12b-1) Fees" include all distribution or other expenses incurred during the most recent fiscal year under a plan adopted pursuant to rule 12b-1 [17 CFR 270.12b-1]. 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 falsefalse0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalse4falseRowprimaryElement*7false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00340.0034[1]falsefalsefalsetruefalseOtherrr: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 falsefalse0rr_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1truetruetrue0.00340.0034falsefalsefalsetruefalseOthernanafalsefalse5falseRowprimaryElement*8false0rr_ExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00820.0082falsefalsefalsetruefalseOtherrr: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 falsefalse0rr_ExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00820.0082falsefalsefalsetruefalseOthernanafalsefalse6falseRowprimaryElement*9false0rr_FeeWaiverOrReimbursementOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue-0.0014-0.0014[2]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 falsefalse0rr_FeeWaiverOrReimbursementOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[2]1truetruetrue-0.0014-0.0014falsefalsefalsetruefalseOthernanafalsefalse7falseRowprimaryElement*10false0rr_NetExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00680.0068[2]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 falsefalse0rr_NetExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[2]1truetruetrue0.00680.0068falsefalsefalsetruefalseOthernanafalsefalse1Other expenses are based on estimated amounts for the current fiscal year. 2The investment manager and its affiliates have contractually agreed to waive certain fees and to reimburse certain expenses (other than acquired fund fees and expenses, if any) until Sept. 30, 2011, 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 (excluding acquired fund fees and expenses, if any, will not exceed 0.69% for Class Z. 17Annual Fund Operating Expenses - Columbia U.S. Government Mortgage Fund (Class Z Shares) UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to OperatingExpensesData.No authoritative reference available.falsefalse12false0rr_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 falsefalse13false0rr_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 the Fund for the time periods indicated and then redeem your shares at the end of those periods (unless otherwise noted). The Example also assumes that your investment has a 5% return each year and that the Fund&#8217;s operating expenses remain the same. The Example includes contractual commitments to waive fees and reimburse expenses 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 falsefalse14false0rr_ExpenseExampleWithRedemptionTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://columbiamanagement.com/role/ExpenseExampleColumbiaUSGovernmentMortgageFundClassZShares column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfst1352280_S000031344_Member * row dei_LegalEntityAxis compact cfst1352280_Prospectus_One_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;"&gt;~ http://columbiamanagement.com/role/ExpenseExampleColumbiaUSGovernmentMortgageFundClassZShares column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfst1352280_S000031344_Member * row dei_LegalEntityAxis compact cfst1352280_Prospectus_One_Member * ~&lt;/div&gt; </div>truehttp://columbiamanagement.com/role/ExpenseExampleColumbiaUSGovernmentMortgageFundClassZSharesfalsefalse0200306 - Schedule - Expense Example - Columbia U.S. Government Mortgage Fund (Class Z Shares) {Transposed}truefalsefalse1falseColumnprimaryElement*4false0rr_ExpenseExampleByYearColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class ZfalsefalsefalsetruefalseOtherus-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 falsefalsefalseUSDfalsefalse$2falseColumnprimaryElement*5false0rr_ExpenseExampleYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue6969falsefalsefalsetruefalseMonetaryrr: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 falsefalsefalseUSDfalsefalse$3falseColumnprimaryElement*6false0rr_ExpenseExampleYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue248248falsefalsefalsetruefalseMonetaryrr: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 falsefalsefalseUSDfalsefalse$4falseColumnprimaryElement*7false0rr_ExpenseExampleYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue442442falsefalsefalsetruefalseMonetaryrr: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 falsefalsefalseUSDfalsefalse$5falseColumnprimaryElement*8false0rr_ExpenseExampleYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue10051005falsefalsefalsetruefalseMonetaryrr: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 falsefalsefalseUSDfalsefalse$1falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-02-19T00:00:002011-02-18T00:00:00falsefalseColumbia U.S. Government Mortgage Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_S000031344Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass Z Sharesdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_ProspectusOneMemberdei_LegalEntityAxisexplicitMemberfalsefalseColumbia U.S. Government Mortgage Fund - Class Zrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_C000097361Memberrr_ProspectusShareClassAxisexplicitMemberColumbia U.S. Government Mortgage FundClass Z SharesColumbia U.S. Government Mortgage Fund - Class ZUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class ZClass Zfalsefalsefalsetruefalse2truefalsetrue6969falsefalsefalsetruefalse3truefalsetrue248248falsefalsefalsetruefalse4truefalsetrue442442falsefalsefalsetruefalse5truefalsetrue10051005falsefalsefalsetruefalseOthernanafalsefalse51Expense Example - Columbia U.S. Government Mortgage Fund (Class Z Shares) (USD $)UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ExpenseExample.No authoritative reference available.falsefalse15false0rr_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 falsefalse16false0rr_PortfolioTurnoverTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund pays transaction costs, such as commissions, when it buys and sells securities (or &#8220;turns over&#8221; its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund&#8217;s performance. During the most recent fiscal year, the Fund&#8217;s portfolio turnover rate was 519% 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 falsefalse17false0rr_PortfolioTurnoverRaterrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse5.195.19falsefalsefalsefalsefalseOtherxbrli:pureItemTypepureThis element represents the rate of portfolio turnover presented as a percentage (SEC Form N-1A 2006-09-14 A.3.example.3 Portfolio Turnover A.3.instructions.5 Portfolio Turnover).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subsection example falsefalse18false0rr_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 falsefalse19false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund&#8217;s assets primarily are invested in mortgage-backed securities. Under normal market conditions, at least 80% of the Fund&#8217;s net assets (including the amount of any borrowings for investment purposes) are invested in mortgage related securities that either are issued or guaranteed as to principal and interest by the U.S. government, its agencies, authorities or instrumentalities. This includes, but is not limited to Government National Mortgage Association (GNMA or Ginnie Mae) mortgage-backed bonds, which are backed by the full faith and credit of the United States; and Federal National Mortgage Association (FNMA or Fannie Mae) and Federal Home Loan Mortgage Corporation (FHLMC or Freddie Mac) mortgage-backed bonds. FNMA and FHLMC are chartered or sponsored by Acts of Congress; however, their securities are neither issued nor guaranteed by the United States Treasury. The Fund will provide shareholders with at least 60 days&#8217; written notice of any change in the 80% policy. The Fund may invest in fixed income securities of any maturity and does not seek to maintain a particular dollar-weighted average maturity.</p><p>In pursuit of the Fund&#8217;s objectives, the Fund&#8217;s investment manager (Columbia Management Investment Advisers, LLC) chooses investments by reviewing the relative value within the U.S. Government mortgage sector, the interest rate outlook and the yield curve.</p><p>In evaluating whether to sell a security, the investment manager considers, among other factors, whether the interest rate or economic outlook changes, the security is overvalued relative to alternative investments, a more attractive opportunity exists and/or the issuer or the security continues to meet the other standards described above.</p><p>The investment manager may use derivatives such as futures, options, forward contracts and swaps, including credit default swaps, in an effort to produce incremental earnings, to hedge existing positions, to increase market exposure and investment flexibility, or to obtain or reduce credit exposure.</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 falsefalse20false0rr_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 falsefalse21false0rr_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:</p><p><b>Active Management Risk.</b> Due to its active management, the Fund could underperform other mutual funds with similar investment objectives.</p><p><b> Credit Risk.</b> Credit risk is the risk that fixed-income securities in the Fund&#8217;s portfolio will decline in price or fail to pay interest or repay principal when due because the issuer of the security or the counterparty to a contract will default or otherwise become unable or unwilling to honor its financial obligations. Unrated securities held by the Fund present increased credit risk.</p><p><b>Derivatives Risk.</b> The Fund&#8217;s use of derivatives involves risks different from, and possibly greater than, the risks associated with investing directly in the investments underlying the derivatives. Derivatives may be volatile and involve significant risk, such as, among other things, correlation risk, counterparty credit risk, hedging risk, leverage risk and liquidity risk. Certain derivatives have the potential for unlimited losses, regardless of the size of the initial investment.</p><p><b>Interest Rate Risk.</b> Interest rate risk is the risk of losses attributable to changes in interest rates. When interest rates rise, prices of fixed-income securities generally fall. In general, the longer the maturity or duration of a fixed-income security, the greater its sensitivity to changes in interest rates. Interest rate changes also may increase prepayments of debt obligations.</p><p><b>Market Risk.</b> The market value of securities may fall, fail to rise or fluctuate, sometimes rapidly and unpredictably. Market risk may affect a single issuer, sector of the economy, industry, or the market as a whole.</p><p><b>Prepayment and Extension Risk.</b> Prepayment and extension risk is the risk that a loan, bond or other security might be called or otherwise converted, prepaid or redeemed before maturity, and the portfolio managers may not be able to invest the proceeds in securities or loans providing as high a level of income, resulting in a reduced yield to the Fund. As interest rates rise or spreads widen, the likelihood of prepayment decreases. The portfolio managers (or Subadvisers) may be unable to capitalize on securities with higher interest rates or wider spreads because the Fund&#8217;s investments are locked in at a lower rate for a longer period of time.</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 falsefalse22false0rr_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 falsefalse23false0rr_PerformanceNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>Class Z shares are new as of the date of this prospectus and therefore performance is not yet available. The following bar chart and table provide some illustration of the risks of investing in the Fund by showing, for the Fund&#8217;s Class A shares (which are not offered under this prospectus), respectively:</p><p>&#8226; how the Fund&#8217;s Class A performance has varied for each full calendar year shown on the bar chart; and </p><p>&#8226; how the Fund&#8217;s Class A average annual total returns compare to recognized measures of market performance shown on the table.</p><p>The sales charge for Class A shares is not reflected in the bar chart or the table. Class Z shares are not subject to a sales charge. If the Class A sales charge was reflected, returns would be lower than those shown.</p><p>How the Fund has performed in the past (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information can be obtained by calling toll-free 800.345.6611 or visiting columbiamanagement.com.</p><p>After-tax returns are shown for Class A shares. After-tax returns for Class Z shares will vary. After-tax returns are calculated using the highest historical individual federal marginal income tax rate and do not reflect the impact of state and local taxes. Actual after-tax returns will depend on your tax situation and most likely will differ from the returns shown in the table. If you hold your shares in a tax-deferred account, such as a 401(k) plan or an IRA, the after-tax returns do not apply to you since you will not incur taxes until you begin to withdraw from your account.</p>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 falsefalse24false0rr_BarChartHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00CLASS A ANNUAL TOTAL RETURNS (BEFORE SALES CHARGE)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalse25false0rr_BarChartTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://columbiamanagement.com/role/AnnualTotalReturnsBarChartColumbiaUSGovernmentMortgageFundClassZShares column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfst1352280_S000031344_Member * row dei_LegalEntityAxis compact cfst1352280_Prospectus_One_Member * ~&lt;/div&gt; </div>falsefalseBarChart6.jpg<div> &lt;div style="display:none;"&gt;~ http://columbiamanagement.com/role/AnnualTotalReturnsBarChartColumbiaUSGovernmentMortgageFundClassZShares column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfst1352280_S000031344_Member * row dei_LegalEntityAxis compact cfst1352280_Prospectus_One_Member * ~&lt;/div&gt; </div>falsehttp://columbiamanagement.com/role/AnnualTotalReturnsBarChartColumbiaUSGovernmentMortgageFundClassZSharesfalsefalse0200506 - Schedule - Annual Total Returns (Bar Chart) - Columbia U.S. Government Mortgage Fund (Class Z Shares)truefalsefalse1falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2010-02-19T00:00:002011-02-18T00:00:00falsefalseColumbia U.S. Government Mortgage Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_S000031344Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass Z Sharesdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_ProspectusOneMemberdei_LegalEntityAxisexplicitMemberfalsefalseColumbia U.S. Government Mortgage Fund - Class Arr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_C000097356Memberrr_ProspectusShareClassAxisexplicitMemberColumbia U.S. Government Mortgage FundClass Z SharesColumbia U.S. Government Mortgage Fund - Class AStandard0falseUSDfalsefalse$1falseRowprimaryElement*4false0rr_AnnualReturn2003rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.03040.0304falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse0rr_AnnualReturn2003truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.03040.0304falsefalsefalsetruefalseOthernanafalsefalse2falseRowprimaryElement*5false0rr_AnnualReturn2004rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.04050.0405falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse0rr_AnnualReturn2004truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.04050.0405falsefalsefalsetruefalseOthernanafalsefalse3falseRowprimaryElement*6false0rr_AnnualReturn2005rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.02220.0222falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse0rr_AnnualReturn2005truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.02220.0222falsefalsefalsetruefalseOthernanafalsefalse4falseRowprimaryElement*7false0rr_AnnualReturn2006rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.04340.0434falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse0rr_AnnualReturn2006truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.04340.0434falsefalsefalsetruefalseOthernanafalsefalse5falseRowprimaryElement*8false0rr_AnnualReturn2007rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.05040.0504falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse0rr_AnnualReturn2007truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.05040.0504falsefalsefalsetruefalseOthernanafalsefalse6falseRowprimaryElement*9false0rr_AnnualReturn2008rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.0314-0.0314falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse0rr_AnnualReturn2008truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.0314-0.0314falsefalsefalsetruefalseOthernanafalsefalse7falseRowprimaryElement*10false0rr_AnnualReturn2009rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.12520.1252falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse0rr_AnnualReturn2009truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.12520.1252falsefalsefalsetruefalseOthernanafalsefalse8falseRowprimaryElement*11false0rr_AnnualReturn2010rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.10270.1027falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse0rr_AnnualReturn2010truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.10270.1027falsefalsefalsetruefalseOthernanafalsefalse18Annual Total Returns (Bar Chart) - Columbia U.S. Government Mortgage Fund (Class Z Shares) UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to BarChartData.No authoritative reference available.falsefalse26false0rr_BarChartClosingTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>During the periods shown:</p><p>&#8226; Highest return for a calendar quarter was +4.67% (quarter ended Sept. 30, 2009)</p><p> &#8226; Lowest return for a calendar quarter was -2.47% (quarter ended Dec. 31, 2008)</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse27false0rr_AverageAnnualReturnCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00Average Annual Total Returns (without sales charge)(for periods ended Dec. 31, 2010)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringThis item represents Average Anuual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 5 -Subsection b falsefalse28false0rr_PerformanceTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://columbiamanagement.com/role/AverageAnnualTotalReturnsColumbiaUSGovernmentMortgageFundClassZShares column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfst1352280_S000031344_Member * row dei_LegalEntityAxis compact cfst1352280_Prospectus_One_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;"&gt;~ http://columbiamanagement.com/role/AverageAnnualTotalReturnsColumbiaUSGovernmentMortgageFundClassZShares column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact cfst1352280_S000031344_Member * row dei_LegalEntityAxis compact cfst1352280_Prospectus_One_Member * ~&lt;/div&gt; </div>truehttp://columbiamanagement.com/role/AverageAnnualTotalReturnsColumbiaUSGovernmentMortgageFundClassZSharesfalsefalse0200606 - Schedule - Average Annual Total Returns - Columbia U.S. Government Mortgage Fund (Class Z Shares) {Transposed}truefalsefalse1falseColumnprimaryElement*4false0rr_AverageAnnualReturnColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00Columbia U.S. Government Mortgage Fund:falsefalsefalsetruefalse2falsetruefalse00Columbia U.S. Government Mortgage Fund:falsefalsefalsetruefalse3falsetruefalse00Columbia U.S. Government Mortgage Fund:falsefalsefalsetruefalse4falsetruefalse00falsefalsefalsetruefalse5falsetruefalse00falsefalsefalsetruefalseOtherus-types:textBlockItemTypestringThis item represents Average Anuual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 1 -Subsection b falsefalsefalseUSDfalsefalse$2falseColumnprimaryElement*5false0rr_AverageAnnualReturnLabelrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00Class A before taxes[1]falsefalsefalsetruefalse2falsetruefalse00Class A after taxes on distributions[1]falsefalsefalsetruefalse3falsetruefalse00Class A after taxes on distributions and redemption of fund shares[1]falsefalsefalsetruefalse4falsetruefalse00Barclays Capital U.S. Mortgage-Backed Securities Indexfalsefalsefalsetruefalse5falsetruefalse00Lipper U.S. Mortgage Funds IndexfalsefalsefalsetruefalseOtherxbrli:stringItemTypestringThis item represents Average Anuual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalsefalseUSDfalsefalse$3falseColumnprimaryElement*6false0rr_IndexNoDeductionForFeesExpensesTaxesrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsetruefalse2falsefalsefalse00falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalse4falsefalsefalse00(reflects no deduction for fees, expenses or taxes)falsefalsefalsetruefalse5falsefalsefalse00(reflects no deduction for fees or taxes)falsefalsefalsetruefalseOtherxbrli:stringItemTypestringThe Performance Table includes a parenthetical, indicating that the Index "(reflects no deduction for fees, expenses or taxes)". This tag is used when this is reflected in a footnote.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 5 -Subsection b falsefalsefalseUSDfalsefalse$4falseColumnprimaryElement*7false0rr_AverageAnnualReturnYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.10270.1027falsefalsefalsetruefalse2truetruetrue0.08550.0855falsefalsefalsetruefalse3truetruetrue0.06640.0664falsefalsefalsetruefalse4truetruetrue0.05370.0537falsefalsefalsetruefalse5truetruetrue0.06610.0661falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalsefalseUSDfalsefalse$5falseColumnprimaryElement*8false0rr_AverageAnnualReturnYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.05660.0566falsefalsefalsetruefalse2truetruetrue0.03960.0396falsefalsefalsetruefalse3truetruetrue0.03820.0382falsefalsefalsetruefalse4truetruetrue0.06340.0634falsefalsefalsetruefalse5truetruetrue0.05480.0548falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalsefalseUSDfalsefalse$6falseColumnprimaryElement*10false0rr_AverageAnnualReturnSinceInceptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.05020.0502falsefalsefalsetruefalse2truetruetrue0.03420.0342falsefalsefalsetruefalse3truetruetrue0.03340.0334falsefalsefalsetruefalse4truetruetrue0.05540.0554falsefalsefalsetruefalse5truetruetrue0.04780.0478falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalsefalseUSDfalsefalse$7falseColumnprimaryElement*11false0rr_AverageAnnualReturnInceptionDaterrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse002002-02-14falsefalsetruetruefalse2falsetruefalse002002-02-14falsefalsetruetruefalse3falsetruefalse002002-02-14falsefalsetruetruefalse4falsetruefalse002002-02-14falsefalsetruetruefalse5falsetruefalse002002-02-14falsefalsetruetruefalseOtherxbrli:dateItemTypedateReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 4 -Subsection b falsefalsefalseUSDfalsefalse$1falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-02-19T00:00:002011-02-18T00:00:00falsefalseColumbia U.S. Government Mortgage Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_S000031344Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalsebefore taxesrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_ReturnBeforeTaxMemberrr_PerformanceMeasureAxisexplicitMemberfalsefalseClass Z Sharesdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_ProspectusOneMemberdei_LegalEntityAxisexplicitMemberfalsefalseColumbia U.S. Government Mortgage Fund - Class Arr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_C000097356Memberrr_ProspectusShareClassAxisexplicitMemberColumbia U.S. Government Mortgage Fundbefore taxesClass Z SharesColumbia U.S. Government Mortgage Fund - Class AStandard00truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00Columbia U.S. Government Mortgage Fund:Columbia U.S. Government Mortgage Fund:falsefalsefalsetruefalse2falsetruefalse00Class A before taxesClass A before taxes[1]falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsefalsefalse4truetruetrue0.10270.1027falsefalsefalsetruefalse5truetruetrue0.05660.0566falsefalsefalsetruefalse6truetruetrue0.05020.0502falsefalsefalsetruefalse7falsetruefalse002002-02-142002-02-14falsefalsetruetruefalseOthernanafalsefalse2falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-02-19T00:00:002011-02-18T00:00:00falsefalseColumbia U.S. Government Mortgage Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_S000031344Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseafter taxes on distributionsrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldirr_AfterTaxesOnDistributionsMemberrr_PerformanceMeasureAxisexplicitMemberfalsefalseClass Z Sharesdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_ProspectusOneMemberdei_LegalEntityAxisexplicitMemberfalsefalseColumbia U.S. Government Mortgage Fund - Class Arr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_C000097356Memberrr_ProspectusShareClassAxisexplicitMemberColumbia U.S. Government Mortgage Fundafter taxes on distributionsClass Z SharesColumbia U.S. Government Mortgage Fund - Class AStandard00truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00Columbia U.S. Government Mortgage Fund:Columbia U.S. Government Mortgage Fund:falsefalsefalsetruefalse2falsetruefalse00Class A after taxes on distributionsClass A after taxes on distributions[1]falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsefalsefalse4truetruetrue0.08550.0855falsefalsefalsetruefalse5truetruetrue0.03960.0396falsefalsefalsetruefalse6truetruetrue0.03420.0342falsefalsefalsetruefalse7falsetruefalse002002-02-142002-02-14falsefalsetruetruefalseOthernanafalsefalse3falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-02-19T00:00:002011-02-18T00:00:00falsefalseColumbia U.S. Government Mortgage Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_S000031344Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseafter taxes on distributions and redemption of fund sharesrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldirr_AfterTaxesOnDistributionsAndSalesMemberrr_PerformanceMeasureAxisexplicitMemberfalsefalseClass Z Sharesdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_ProspectusOneMemberdei_LegalEntityAxisexplicitMemberfalsefalseColumbia U.S. Government Mortgage Fund - Class Arr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_C000097356Memberrr_ProspectusShareClassAxisexplicitMemberColumbia U.S. Government Mortgage Fundafter taxes on distributions and redemption of fund sharesClass Z SharesColumbia U.S. Government Mortgage Fund - Class AStandard00truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00Columbia U.S. Government Mortgage Fund:Columbia U.S. Government Mortgage Fund:falsefalsefalsetruefalse2falsetruefalse00Class A after taxes on distributions and redemption of fund sharesClass A after taxes on distributions and redemption of fund shares[1]falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsefalsefalse4truetruetrue0.06640.0664falsefalsefalsetruefalse5truetruetrue0.03820.0382falsefalsefalsetruefalse6truetruetrue0.03340.0334falsefalsefalsetruefalse7falsetruefalse002002-02-142002-02-14falsefalsetruetruefalseOthernanafalsefalse4falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-02-19T00:00:002011-02-18T00:00:00falsefalseBarclays Capital U.S. Mortgage-Backed Securities Indexdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_BarclaysCapitalUSMortgageBackedSecuritiesIndexMemberdei_DocumentInformationDocumentAxisexplicitMembertruefalsePerformance Measurerr_PerformanceMeasureAxisrr_PerformanceMeasureDomainrr_PerformanceMeasureAxisexplicitMemberfalsefalseClass Z Sharesdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_ProspectusOneMemberdei_LegalEntityAxisexplicitMembertruefalseShare Classesrr_ProspectusShareClassAxisrr_ShareClassDomainrr_ProspectusShareClassAxisexplicitMemberBarclays Capital U.S. Mortgage-Backed Securities IndexPerformance MeasureClass Z SharesShare ClassesStandard00truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsetruefalse00Barclays Capital U.S. Mortgage-Backed Securities IndexBarclays Capital U.S. Mortgage-Backed Securities Indexfalsefalsefalsetruefalse3falsefalsefalse00(reflects no deduction for fees, expenses or taxes)(reflects no deduction for fees, expenses or taxes)falsefalsefalsetruefalse4truetruetrue0.05370.0537falsefalsefalsetruefalse5truetruetrue0.06340.0634falsefalsefalsetruefalse6truetruetrue0.05540.0554falsefalsefalsetruefalse7falsetruefalse002002-02-142002-02-14falsefalsetruetruefalseOthernanafalsefalse5falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-02-19T00:00:002011-02-18T00:00:00falsefalseLipper U.S. Mortgage Funds Indexdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_LipperUSMortgageFundsIndexMemberdei_DocumentInformationDocumentAxisexplicitMembertruefalsePerformance Measurerr_PerformanceMeasureAxisrr_PerformanceMeasureDomainrr_PerformanceMeasureAxisexplicitMemberfalsefalseClass Z Sharesdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldicfst1352280_ProspectusOneMemberdei_LegalEntityAxisexplicitMembertruefalseShare Classesrr_ProspectusShareClassAxisrr_ShareClassDomainrr_ProspectusShareClassAxisexplicitMemberLipper U.S. Mortgage Funds IndexPerformance MeasureClass Z SharesShare ClassesStandard00truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsetruefalse00Lipper U.S. Mortgage Funds IndexLipper U.S. Mortgage Funds Indexfalsefalsefalsetruefalse3falsefalsefalse00(reflects no deduction for fees or taxes)(reflects no deduction for fees or taxes)falsefalsefalsetruefalse4truetruetrue0.06610.0661falsefalsefalsetruefalse5truetruetrue0.05480.0548falsefalsefalsetruefalse6truetruetrue0.04780.0478falsefalsefalsetruefalse7falsetruefalse002002-02-142002-02-14falsefalsetruetruefalseOthernanafalsefalse1The returns shown are for Class A shares without the applicable front-end sales charge. Class Z shares, which are sold without a sales charge, would have substantially similar annual returns as Class A shares because the classes of shares invest in the same portfolio of securities and would differ only to the extent that the classes do not have the same expenses. Class A share returns have not been adjusted to reflect differences in class-related expenses. If differences in class-related expenses were reflected (i.e., if expenses of Class Z shares were reflected in the Class A share returns), the returns shown for Class A shares for all periods would be higher. 75Average Annual Total Returns - Columbia U.S. Government Mortgage Fund (Class Z Shares) Class Z SharesUnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to PerformanceTableData.No authoritative reference available.falsefalse29false0rr_PerformanceTableNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Fund performance information prior to March 7, 2011 represents that of the Fund as a series of RiverSource Government Income Series, Inc., a Minnesota corporation. The Fund was reorganized into a series of Columbia Funds Series Trust II, a Massachusetts business trust, on that date.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringIf the Fund has annual returns for at least one calendar year, provide a table showing the Fund's (A) average annual total return; (B) average annual total return (after taxes on distributions); and (C) average annual total return (after taxes on distributions and redemption). A Money Market Fund should show only the returns described in clause (A) of the preceding sentence. All returns should be shown for 1-, 5-, and 10- calendar year periods ending on the date of the most recently completed calendar year (or for the life of the Fund, if shorter), but only for periods subsequent to the effective date of the Fund's registration statement. The table also shouldshow the returns of an appropriate broadbased securities market index as defined in Instruction 5 to Item 22(b)(7) for the same periods. A Fund that has been in existence for more than 10 years also may include returns for the life of the Fund. A Money Market Fund may provide the Fund's 7-day yield ending on the date of the most recent calendar year or disclose a toll-free (or collect) telephone number that investors can use to obtain the Fund's current 7-day yield. For a Fund (other than a Money Market Fund or a Fund described in General Instruction C.3.(d)(iii)), provide the information in the following table with the specified captions AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, _____). For a Fund that provides annual total returns for only one calendar year or for a Fund that does not include the bar chart because it does not have annual returns for a full calendar year, modify, as appropriate, the narrative explanation required by paragraph (c)(2)(i) (e.g., by stating that the information gives some indication of the risks of an investment in the Fund by comparing the Fund's performance with a broad measure of market performance).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iv -Subsection b falsefalse128Risk/Return Summary - Columbia U.S. Government Mortgage Fund (Class Z Shares) (Columbia U.S. Government Mortgage Fund, Class Z Shares)UnKnownUnKnownUnKnownUnKnowntruetrue