Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	COLUMBIA FUNDS SERIES TRUST I
Prospectus Date	rr_ProspectusDate	May 01, 2018
Columbia Real Estate Equity Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	SUMMARY OF THE FUND
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	Columbia Real Estate Equity Fund (the Fund) seeks capital appreciation and above-average income by investing, under normal market conditions, at least 80% of its net assets (plus any borrowings for investment purposes) in the stocks of companies principally engaged in the real estate industry, including real estate investment trusts (REITs).
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses of the Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. The front-end sales charge applicable to Class T shares is a per-transaction charge, meaning that separate orders will not be aggregated for purposes of calculating the rate of the sales charge payable. An investor transacting in a class of Fund shares without any front-end sales charge, contingent deferred sales charge, or other asset-based fee for sales or distribution may be required to pay a commission to the financial intermediary for effecting such transactions. Such commission rates are set by the financial intermediary and are not reflected in the tables or the example below. You may qualify for sales charge discounts if you and members of your immediate family invest, or agree to invest in the future, at least $50,000 in certain classes of shares of eligible funds distributed by Columbia Management Investment Distributors, Inc. (the Distributor). More information is available about these and other sales charge discounts and waivers from your financial intermediary, and can be found in the Choosing a Share Class section beginning on page 17 of the Fund’s prospectus, in Appendix A to the prospectus beginning on page A-1 and in Appendix S to the Statement of Additional Information (SAI) under Sales Charge Waivers beginning on page S-1.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder Fees (fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund may pay transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in 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 27% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	27.00%
Expense Breakpoint Discounts [Text]	rr_ExpenseBreakpointDiscounts	You may qualify for sales charge discounts if you and members of your immediate family invest, or agree to invest in the future, at least $50,000 in certain classes of shares of eligible funds distributed by Columbia Management Investment Distributors, Inc. (the Distributor). More information is available about these and other sales charge discounts and waivers from your financial intermediary, and can be found in the Choosing a Share Class section beginning on page 17 of the Fund’s prospectus, in Appendix A to the prospectus beginning on page A-1 and in Appendix S to the Statement of Additional Information (SAI) under Sales Charge Waivers beginning on page S-1.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	$ 50,000
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	Other expenses have been restated to reflect current transfer agency fees paid by the Fund.
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	The following 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 illustrates the hypothetical expenses that you would incur over the time periods indicated, and assumes that: you invest $10,000 in the applicable class of Fund shares for the periods indicated, your investment has a 5% return each year, and the Fund’s total annual operating expenses remain the same as shown in the Annual Fund Operating Expenses table above. Although your actual costs may be higher or lower, based on the assumptions listed above, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Under normal circumstances, the Fund invests at least 80% of its net assets (including the amount of any borrowings for investment purposes) in equity securities of companies principally engaged in the real estate industry, including REITs. A company is considered to be “principally engaged” in the real estate industry if at least 50% of its gross income or net profits are attributable to the ownership, construction, management or sale of residential, commercial or industrial real estate. The Fund may invest in equity REITs, mortgage REITs and hybrid REITs. The Fund is non-diversified, which means that it can invest a greater percentage of its assets in the securities of fewer issuers than can a diversified fund.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	An investment in the Fund involves risks, including those described below. There is no assurance that the Fund will achieve its investment objective and you may lose money. The value of the Fund’s holdings may decline, and the Fund’s net asset value (NAV) and share price may go down. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Active Management Risk. Due to its active management, the Fund could underperform its benchmark index and/or other funds with similar investment objectives and/or strategies. Changing Distribution Level Risk. The Fund will normally receive income which may include interest, dividends and/or capital gains, depending upon its investments. The amount of the distributions the Fund pays will vary and generally depends on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund’s income or net capital gains from its investments may reduce its distribution level. Focused Portfolio Risk. Because the Fund may invest in a limited number of companies, the Fund as a whole is subject to greater risk of loss if any of those securities decline in price. Issuer Risk. An issuer in which the Fund invests or to which it has exposure may perform poorly, and the value of its securities may therefore decline, which would negatively affect the Fund’s performance. Poor performance may be caused by poor management decisions, competitive pressures, breakthroughs in technology, reliance on suppliers, labor problems or shortages, corporate restructurings, fraudulent disclosures, natural disasters or other events, conditions or factors. The market capitalization of an issuer may also impact its risk profile. Investments in larger, more established companies may involve certain risks associated with their larger size. For instance, larger, more established companies may be less able to respond quickly to new competitive challenges, such as changes in consumer tastes or innovation from smaller competitors. Also, larger companies are sometimes less able to attain the high growth rates of successful smaller companies, especially during extended periods of economic expansion. Market Risk. Market risk refers to the possibility that the market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. An investment in the Fund could lose money over short or long periods. Non-Diversified Fund Risk. The Fund is non-diversified, which generally means that it will invest a greater percentage of its total assets in the securities of fewer issuers than a “diversified” fund. This increases the risk that a change in the value of any one investment held by the Fund could affect the overall value of the Fund more than it would affect that of a diversified fund holding a greater number of investments. Accordingly, the Fund's value will likely be more volatile than the value of a more diversified fund. Real Estate-Related Investment Risk. Investments in real estate investment trusts (REITs) and in securities of other companies (wherever organized) principally engaged in the real estate industry subject the Fund to, among other things, risks similar to those of direct investments in real estate and the real estate industry in general. These include risks related to general and local economic conditions, possible lack of availability of financing and changes in interest rates or property values. REITs are entities that either own properties or make construction or mortgage loans, and also may include operating or finance companies. The value of interests in a REIT may be affected by, among other factors, changes in the value of the underlying properties owned by the REIT, changes in the prospect for earnings and/or cash flow growth of the REIT itself, defaults by borrowers or tenants, market saturation, decreases in market rates for rents, and other economic, political, or regulatory matters affecting the real estate industry, including REITs. REITs and similar non-U.S. entities depend upon specialized management skills, may have limited financial resources, may have less trading volume in their securities, and may be subject to more abrupt or erratic price movements than the overall securities markets. REITs are also subject to the risk of failing to qualify for favorable tax treatment under the Internal Revenue Code of 1986, as amended. Some REITs (especially mortgage REITs) are affected by risks similar to those associated with investments in debt securities including changes in interest rates and the quality of credit extended. Because the value of REITs and other real estate-related companies may fluctuate widely in response to changes in factors affecting the real estate markets, the value of an investment in the Fund may be more volatile than the value of an investment in a fund that is invested in a more diverse range of market sectors.
Risk Lose Money [Text]	rr_RiskLoseMoney	There is no assurance that the Fund will achieve its investment objective and you may lose money.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-Diversified Fund Risk. The Fund is non-diversified, which generally means that it will invest a greater percentage of its total assets in the securities of fewer issuers than a “diversified” fund. This increases the risk that a change in the value of any one investment held by the Fund could affect the overall value of the Fund more than it would affect that of a diversified fund holding a greater number of investments. Accordingly, the Fund's value will likely be more volatile than the value of a more diversified fund.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table show you how the Fund has performed in the past, and can help you understand the risks of investing in the Fund. The bar chart shows how the Fund’s Class A share performance (without sales charges) has varied for each full calendar year shown. If the sales charges were reflected, returns shown would be lower. The table below the bar chart compares the Fund’s returns (after applicable sales charges shown in the Shareholder Fees table in this prospectus) for the periods shown with a broad measure of market performance. The performance of one or more share classes shown in the table below begins before the indicated inception date for such share class. The returns shown for each such share class include the returns of the Fund’s Class Inst shares (adjusted to reflect the higher class-related operating expenses of such classes, where applicable) for periods prior to its inception date. Except for differences in annual returns resulting from differences in expenses and sales charges (where applicable), the share classes of the Fund would have substantially similar annual returns because all share classes of the Fund invest in the same portfolio of securities. The after-tax returns shown in the Average Annual Total Returns table below are calculated using the highest historical individual U.S. federal marginal income tax rates in effect during the period indicated in the table and do not reflect the impact of state, local or foreign taxes. Your actual after-tax returns will depend on your personal tax situation and may differ from those shown in the table. In addition, the after-tax returns shown in the table do not apply to shares held in tax-advantaged accounts such as 401(k) plans or Individual Retirement Accounts (IRAs). The after-tax returns are shown only for Class A shares and will vary for other share classes. Returns after taxes on distributions and sale of Fund shares are higher than before-tax returns for certain periods shown because they reflect the tax benefit of capital losses realized on the redemption of Fund shares. The Fund’s past performance (before and after taxes) is no guarantee of how the Fund will perform in the future. Updated performance information can be obtained by calling toll-free 800.345.6611 or visiting columbiathreadneedle.com/us.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following bar chart and table show you how the Fund has performed in the past, and can help you understand the risks of investing in the Fund. The bar chart shows how the Fund’s Class A share performance (without sales charges) has varied for each full calendar year shown. If the sales charges were reflected, returns shown would be lower. The table below the bar chart compares the Fund’s returns (after applicable sales charges shown in the Shareholder Fees table in this prospectus) for the periods shown with a broad measure of market performance.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	800.345.6611
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	columbiathreadneedle.com/us
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The Fund’s past performance (before and after taxes) is no guarantee of how the Fund will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	Year by Year Total Return (%) as of December 31 Each Year
Bar Chart Does Not Reflect Sales Loads [Text]	rr_BarChartDoesNotReflectSalesLoads	The bar chart shows how the Fund’s Class A share performance (without sales charges) has varied for each full calendar year shown. If the sales charges were reflected, returns shown would be lower.
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Best and Worst Quarterly Returns During the Period Shown in the Bar Chart Best                                                          3rd Quarter 2009                                                         28.25% Worst                                                       4th Quarter 2008                                                        -37.67%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns After Applicable Sales Charges (for periods ended December 31, 2017)
Performance Table Does Reflect Sales Loads	rr_PerformanceTableDoesReflectSalesLoads	The table below the bar chart compares the Fund’s returns (after applicable sales charges shown in the Shareholder Fees table in this prospectus) for the periods shown with a broad measure of market performance.
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns shown in the Average Annual Total Returns table below are calculated using the highest historical individual U.S. federal marginal income tax rates in effect during the period indicated in the table and do not reflect the impact of state, local or foreign taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	In addition, the after-tax returns shown in the table do not apply to shares held in tax-advantaged accounts such as 401(k) plans or Individual Retirement Accounts (IRAs).
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	The after-tax returns are shown only for Class A shares and will vary for other share classes.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	Returns after taxes on distributions and sale of Fund shares are higher than before-tax returns for certain periods shown because they reflect the tax benefit of capital losses realized on the redemption of Fund shares.
Columbia Real Estate Equity Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	5.75%
Maximum deferred sales charge (load) imposed on redemptions (as a % of the lower of the original purchase price or current net asset value)	rr_MaximumDeferredSalesChargeOverOther	1.00%	[1]
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	0.29%	[2]
Total annual Fund operating expenses	rr_ExpensesOverAssets	1.29%
Expenses Deferred Charges [Text Block]	rr_ExpensesDeferredChargesTextBlock	This charge is imposed on certain investments of between $1 million and $50 million redeemed within 18 months after purchase, as follows: 1.00% if redeemed within 12 months after purchase, and 0.50% if redeemed more than 12, but less than 18, months after purchase, with certain limited exceptions.
1 year	rr_ExpenseExampleYear01	$ 699
3 years	rr_ExpenseExampleYear03	960
5 years	rr_ExpenseExampleYear05	1,242
10 years	rr_ExpenseExampleYear10	2,042
1 year	rr_ExpenseExampleNoRedemptionYear01	699
3 years	rr_ExpenseExampleNoRedemptionYear03	960
5 years	rr_ExpenseExampleNoRedemptionYear05	1,242
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 2,042
2008	rr_AnnualReturn2008	(34.80%)	[3]
2009	rr_AnnualReturn2009	26.86%	[3]
2010	rr_AnnualReturn2010	26.04%	[3]
2011	rr_AnnualReturn2011	6.59%	[3]
2012	rr_AnnualReturn2012	16.92%	[3]
2013	rr_AnnualReturn2013	(0.37%)	[3]
2014	rr_AnnualReturn2014	29.08%	[3]
2015	rr_AnnualReturn2015	4.32%	[3]
2016	rr_AnnualReturn2016	4.99%	[3]
2017	rr_AnnualReturn2017	5.07%	[3]
Year to Date Return, Label	rr_YearToDateReturnLabel	Year to Date return
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Mar. 31, 2018
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	(6.56%)
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	28.25%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(37.67%)
1 Year	rr_AverageAnnualReturnYear01	(0.99%)
5 Years	rr_AverageAnnualReturnYear05	6.87%
10 Years	rr_AverageAnnualReturnYear10	6.13%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Nov. 01, 2002
Columbia Real Estate Equity Fund | Class Adv
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load) imposed on redemptions (as a % of the lower of the original purchase price or current net asset value)	rr_MaximumDeferredSalesChargeOverOther	none
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.29%	[2]
Total annual Fund operating expenses	rr_ExpensesOverAssets	1.04%
1 year	rr_ExpenseExampleYear01	$ 106
3 years	rr_ExpenseExampleYear03	331
5 years	rr_ExpenseExampleYear05	574
10 years	rr_ExpenseExampleYear10	1,271
1 year	rr_ExpenseExampleNoRedemptionYear01	106
3 years	rr_ExpenseExampleNoRedemptionYear03	331
5 years	rr_ExpenseExampleNoRedemptionYear05	574
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 1,271
1 Year	rr_AverageAnnualReturnYear01	5.37%
5 Years	rr_AverageAnnualReturnYear05	8.43%
10 Years	rr_AverageAnnualReturnYear10	7.02%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Nov. 08, 2012
Columbia Real Estate Equity Fund | Class C
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load) imposed on redemptions (as a % of the lower of the original purchase price or current net asset value)	rr_MaximumDeferredSalesChargeOverOther	1.00%	[4]
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses	rr_OtherExpensesOverAssets	0.29%	[2]
Total annual Fund operating expenses	rr_ExpensesOverAssets	2.04%
Expenses Deferred Charges [Text Block]	rr_ExpensesDeferredChargesTextBlock	This charge applies to redemptions within 12 months after purchase, with certain limited exceptions.
1 year	rr_ExpenseExampleYear01	$ 307
3 years	rr_ExpenseExampleYear03	640
5 years	rr_ExpenseExampleYear05	1,098
10 years	rr_ExpenseExampleYear10	2,369
1 year	rr_ExpenseExampleNoRedemptionYear01	207
3 years	rr_ExpenseExampleNoRedemptionYear03	640
5 years	rr_ExpenseExampleNoRedemptionYear05	1,098
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 2,369
1 Year	rr_AverageAnnualReturnYear01	3.37%
5 Years	rr_AverageAnnualReturnYear05	7.36%
10 Years	rr_AverageAnnualReturnYear10	5.96%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Oct. 13, 2003
Columbia Real Estate Equity Fund | Class Inst
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load) imposed on redemptions (as a % of the lower of the original purchase price or current net asset value)	rr_MaximumDeferredSalesChargeOverOther	none
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.29%	[2]
Total annual Fund operating expenses	rr_ExpensesOverAssets	1.04%
1 year	rr_ExpenseExampleYear01	$ 106
3 years	rr_ExpenseExampleYear03	331
5 years	rr_ExpenseExampleYear05	574
10 years	rr_ExpenseExampleYear10	1,271
1 year	rr_ExpenseExampleNoRedemptionYear01	106
3 years	rr_ExpenseExampleNoRedemptionYear03	331
5 years	rr_ExpenseExampleNoRedemptionYear05	574
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 1,271
1 Year	rr_AverageAnnualReturnYear01	5.32%
5 Years	rr_AverageAnnualReturnYear05	8.43%
10 Years	rr_AverageAnnualReturnYear10	7.02%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Apr. 01, 1994
Columbia Real Estate Equity Fund | Class Inst2
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load) imposed on redemptions (as a % of the lower of the original purchase price or current net asset value)	rr_MaximumDeferredSalesChargeOverOther	none
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.13%	[2]
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.88%
1 year	rr_ExpenseExampleYear01	$ 90
3 years	rr_ExpenseExampleYear03	281
5 years	rr_ExpenseExampleYear05	488
10 years	rr_ExpenseExampleYear10	1,084
1 year	rr_ExpenseExampleNoRedemptionYear01	90
3 years	rr_ExpenseExampleNoRedemptionYear03	281
5 years	rr_ExpenseExampleNoRedemptionYear05	488
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 1,084
1 Year	rr_AverageAnnualReturnYear01	5.48%
5 Years	rr_AverageAnnualReturnYear05	8.58%
10 Years	rr_AverageAnnualReturnYear10	7.11%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 07, 2011
Columbia Real Estate Equity Fund | Class Inst3
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load) imposed on redemptions (as a % of the lower of the original purchase price or current net asset value)	rr_MaximumDeferredSalesChargeOverOther	none
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.08%	[2]
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.83%
1 year	rr_ExpenseExampleYear01	$ 85
3 years	rr_ExpenseExampleYear03	265
5 years	rr_ExpenseExampleYear05	460
10 years	rr_ExpenseExampleYear10	1,025
1 year	rr_ExpenseExampleNoRedemptionYear01	85
3 years	rr_ExpenseExampleNoRedemptionYear03	265
5 years	rr_ExpenseExampleNoRedemptionYear05	460
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 1,025
1 Year	rr_AverageAnnualReturnYear01	5.51%
5 Years	rr_AverageAnnualReturnYear05	8.47%
10 Years	rr_AverageAnnualReturnYear10	7.04%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 01, 2017
Columbia Real Estate Equity Fund | Class R
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load) imposed on redemptions (as a % of the lower of the original purchase price or current net asset value)	rr_MaximumDeferredSalesChargeOverOther	none
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.50%
Other expenses	rr_OtherExpensesOverAssets	0.29%	[2]
Total annual Fund operating expenses	rr_ExpensesOverAssets	1.54%
1 year	rr_ExpenseExampleYear01	$ 157
3 years	rr_ExpenseExampleYear03	486
5 years	rr_ExpenseExampleYear05	839
10 years	rr_ExpenseExampleYear10	1,834
1 year	rr_ExpenseExampleNoRedemptionYear01	157
3 years	rr_ExpenseExampleNoRedemptionYear03	486
5 years	rr_ExpenseExampleNoRedemptionYear05	839
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 1,834
1 Year	rr_AverageAnnualReturnYear01	4.81%
5 Years	rr_AverageAnnualReturnYear05	7.89%
10 Years	rr_AverageAnnualReturnYear10	6.42%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 27, 2010
Columbia Real Estate Equity Fund | Class T
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	2.50%
Maximum deferred sales charge (load) imposed on redemptions (as a % of the lower of the original purchase price or current net asset value)	rr_MaximumDeferredSalesChargeOverOther	none
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	0.29%	[2]
Total annual Fund operating expenses	rr_ExpensesOverAssets	1.29%
1 year	rr_ExpenseExampleYear01	$ 378
3 years	rr_ExpenseExampleYear03	649
5 years	rr_ExpenseExampleYear05	940
10 years	rr_ExpenseExampleYear10	1,768
1 year	rr_ExpenseExampleNoRedemptionYear01	378
3 years	rr_ExpenseExampleNoRedemptionYear03	649
5 years	rr_ExpenseExampleNoRedemptionYear05	940
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 1,768
1 Year	rr_AverageAnnualReturnYear01	2.47%
5 Years	rr_AverageAnnualReturnYear05	7.60%
10 Years	rr_AverageAnnualReturnYear10	6.51%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 27, 2010
Columbia Real Estate Equity Fund | returns after taxes on distributions | Class A
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(4.40%)
5 Years	rr_AverageAnnualReturnYear05	4.56%
10 Years	rr_AverageAnnualReturnYear10	4.38%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Nov. 01, 2002
Columbia Real Estate Equity Fund | returns after taxes on distributions and sale of Fund shares | Class A
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	1.76%
5 Years	rr_AverageAnnualReturnYear05	4.92%
10 Years	rr_AverageAnnualReturnYear10	4.36%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Nov. 01, 2002
Columbia Real Estate Equity Fund | FTSE Nareit Equity REITS Index (reflects no deductions for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	5.23%
5 Years	rr_AverageAnnualReturnYear05	9.46%
10 Years	rr_AverageAnnualReturnYear10	7.44%

[1] This charge is imposed on certain investments of between $1 million and $50 million redeemed within 18 months after purchase, as follows: 1.00% if redeemed within 12 months after purchase, and 0.50% if redeemed more than 12, but less than 18, months after purchase, with certain limited exceptions.

[2] Other expenses have been restated to reflect current transfer agency fees paid by the Fund.

[3] Year to Date return as of March 31, 2018: -6.56%

[4] This charge applies to redemptions within 12 months after purchase, with certain limited exceptions.