Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	COLUMBIA FUNDS SERIES TRUST I
Prospectus Date	rr_ProspectusDate	Dec. 01, 2018
Columbia U.S. Social Bond Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	SUMMARY OF THE FUND
Objective [Heading]	rr_ObjectiveHeading	<b>Investment Objective </b>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	Columbia U.S. Social Bond Fund (the Fund) seeks total return, consisting of current income and capital appreciation, through investments that seek to support and fund socially beneficial activities and developments, primarily in the U.S.
Expense [Heading]	rr_ExpenseHeading	<b>Fees and Expenses of the Fund </b>
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. 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 25 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	<b>Shareholder Fees (fees paid directly from your investment) </b>
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<b>Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment) </b>
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	November 30, 2019
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<b>Portfolio Turnover </b>
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 21% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	21.00%
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 25 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	<b>Example </b>
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. Since the waivers and/or reimbursements shown in the Annual Fund Operating Expenses table above expire as indicated in the preceding table, they are only reflected in the 1 year example and the first year of the other examples. Although your actual costs may be higher or lower, based on the assumptions listed above, your costs would be:
Strategy [Heading]	rr_StrategyHeading	<b>Principal Investment Strategies </b>
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 bonds and other debt securities of issuers whose principal activities are located in the United States and its territories. The investment manager determines if an issuer’s principal activities are located in the United States or its territories by considering the issuer’s country of organization, its primary stock exchange listing, the source of its revenues, the location of its assets and other factors. Under normal market conditions, the Fund invests at least 60% of its net assets (including the amount of any borrowings for investment purposes) in bonds and other debt securities that pay interest exempt from U.S. federal income tax (but not necessarily the federal alternative minimum tax). These securities are issued by states and their political subdivisions, agencies, authorities and instrumentalities and by other qualified issuers (municipal securities). With respect to the Fund’s investments in municipal securities, the Fund will primarily focus on sectors that the investment manager believes are aimed toward positive environmental and social development such as education, health and social services, affordable housing, economic opportunity and community development, environment and energy, connectivity (such as broadband Internet or mass transit infrastructure) and similar socially impactful sectors. The Fund's investments in municipal securities may include medium grade or below investment grade debt securities or unrated debt securities determined to be of comparable quality. Below investment grade securities are commonly referred to as "junk bonds." The Fund may invest up to 40% of its net assets (including the amount of any borrowings for investment purposes) in bonds and other debt securities issued by corporate and other non-governmental issuers. With respect to the portion of the Fund invested in corporate and other non-governmental issuers, the Fund will primarily invest in bonds that, at the time of purchase, are investment grade or are unrated but determined to be of comparable quality. When evaluating debt securities issued by corporate and other non-governmental issuers, the investment manager will use social issue screens, monitored by a third party service provider, to help ensure that the Fund’s investments in such debt securities are consistent with the Fund’s investment objective. Although specific criteria for exclusion may change from time to time, the Fund will generally not invest in debt securities issued by companies that are determined to be involved in significant controversies relating to environmental, social or governance matters or companies that generate a significant portion of their revenues from ineligible products (such as alcohol, gambling, firearms or tobacco). When selecting which of the eligible debt securities to purchase, the Fund’s investment manager will further consider the environmental, social and governance practices and impacts of the issuer and its products in addition to factors relating to the investment merits of debt securities, such as interest rate, term and credit quality. The Fund may invest in debt instruments that, at the time of purchase, are rated below investment grade or are unrated but determined to be of comparable quality (commonly referred to as “high-yield” investments or “junk” bonds). The Fund may from time to time emphasize one or more sectors in selecting its investments. The Fund may invest in fixed or variable-rate debt securities. The Fund may invest in debt instruments of any maturity and does not seek to maintain either a particular dollar-weighted average maturity or a particular duration. The Fund may invest in the securities and instruments described herein directly or indirectly through investments in other open-end or closed-end investment companies, including municipal bond money market funds. 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	<b>Principal Risks </b>
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. The investment manager’s consideration of social impact may limit the Fund’s investment opportunities and, as a result, the Fund may underperform funds that do not consider social impact or consider it but make different investment decisions based thereon. 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. Credit Risk. Credit risk is the risk that the value of debt instruments may decline if the issuer thereof defaults or otherwise becomes unable or unwilling, or is perceived to be unable or unwilling, to honor its financial obligations, such as making payments to the Fund when due. Debt instruments backed by an issuer's taxing authority may be subject to legal limits on the issuer's power to increase taxes or otherwise to raise revenue, or may be dependent on legislative appropriation or government aid. Certain debt instruments are backed only by revenues derived from a particular project or source, rather than by an issuer's taxing authority, and thus may have a greater risk of default. Rating agencies assign credit ratings to certain debt instruments to indicate their credit risk. Unless otherwise provided in the Fund’s Principal Investment Strategies, investment grade debt instruments are those rated at or above BBB- by S&P Global Ratings, or equivalently rated by Moody’s Investors Service, Inc. or Fitch, Inc., or, if unrated, determined by the management team to be of comparable quality. Conversely, below investment grade (commonly called “high-yield” or “junk”) debt instruments are those rated below BBB- by S&P Global Ratings, or equivalently rated by Moody’s Investors Service, Inc. or Fitch, Inc., or, if unrated, determined by the management team to be of comparable quality. A rating downgrade by such agencies can negatively impact the value of such instruments. Lower quality or unrated instruments held by the Fund may present increased credit risk as compared to higher-rated instruments. Non-investment grade debt instruments may be subject to greater price fluctuations and are more likely to experience a default than investment grade debt instruments and therefore may expose the Fund to increased credit risk. If the Fund purchases unrated instruments, or if the ratings of instruments held by the Fund are lowered after purchase, the Fund will depend on analysis of credit risk more heavily than usual. High-Yield Investments Risk. Securities and other debt instruments held by the Fund that are rated below investment grade (commonly called “high-yield” or “junk” bonds) and unrated debt instruments of comparable quality expose the Fund to a greater risk of loss of principal and income than a fund that invests solely or primarily in investment grade debt instruments. In addition, these investments have greater price fluctuations, are less liquid and are more likely to experience a default than higher-rated debt instruments. High-yield debt instruments are considered to be predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal. Interest Rate Risk. Interest rate risk is the risk of losses attributable to changes in interest rates. In general, if prevailing interest rates rise, the values of debt instruments tend to fall, and if interest rates fall, the values of debt instruments tend to rise. Changes in the value of a debt instrument usually will not affect the amount of income the Fund receives from it but will generally affect the value of your investment in the Fund. Changes in interest rates may also affect the liquidity of the Fund’s investments in debt instruments. In general, the longer the maturity or duration of a debt instrument, the greater its sensitivity to changes in interest rates. Interest rate declines also may increase prepayments of debt obligations, which, in turn, would increase prepayment risk. Similarly, a period of rising interest rates may negatively impact the Fund’s performance. Actions by governments and central banking authorities can result in increases in interest rates. Such actions may negatively affect the value of debt instruments held by the Fund, resulting in a negative impact on the Fund's performance and NAV. Any interest rate increases could cause the value of the Fund’s investments in debt instruments to decrease. Rising interest rates may prompt redemptions from the Fund, which may force the Fund to sell investments at a time when it is not advantageous to do so, which could result in losses. Investing in Other Funds Risk. The Fund’s investment in other funds (affiliated and/or unaffiliated funds) subjects the Fund to the investment performance (positive or negative) and risks of the underlying funds in direct proportion to the Fund’s investment therein. The performance of the underlying funds could be adversely affected if other investors in the same underlying funds make relatively large investments or redemptions in such underlying funds. The Fund, and its shareholders, indirectly bear a portion of the expenses of any funds in which the Fund invests. Because the expenses and costs of an underlying fund are shared by its investors, redemptions by other investors in the underlying funds could result in decreased economies of scale and increased operating expenses for such underlying funds. The Investment Manager typically selects underlying funds from among the funds for which it, or an affiliate, acts as the investment manager (affiliated underlying funds) and will select an unaffiliated underlying fund only if the desired investment exposure is not available through an affiliated fund. The Investment Manager has a conflict of interest in selecting affiliated underlying funds over unaffiliated underlying funds because it receives management fees from affiliated underlying funds, and in selecting among affiliated underlying funds, because the fees paid to it by certain affiliated underlying funds are higher than the fees paid by other affiliated underlying funds. Also, to the extent that the Fund is constrained/restricted from investing (or investing further) in a particular underlying fund for one or more reasons (e.g., underlying fund capacity constraints or regulatory restrictions) or if the Fund chooses to sell its investment in an underlying fund because of poor investment performance or for other reasons, the Fund may have to invest in other underlying funds, including less desirable funds – from a strategy or investment performance standpoint – which could have a negative impact on Fund performance. In addition, Fund performance could be negatively impacted if an appropriate alternate underlying fund is not identified in a timely manner or at all. The underlying funds may not achieve their investment objective. The Fund, through its investment in underlying funds, may not achieve its investment objective. 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. Liquidity Risk. Liquidity risk is the risk associated with any event, circumstance, or characteristic of an investment or market that negatively impacts the Fund’s ability to sell, or realize the proceeds from the sale of, an investment at a desirable time or price. Liquidity risk may arise because of, for example, a lack of marketability of the investment, which means that when seeking to sell its portfolio investments, the Fund could find that selling is more difficult than anticipated, especially during times of high market volatility. Decreases in the number of financial institutions, including banks and broker-dealers, willing to make markets (match up sellers and buyers) in the Fund’s investments or decreases in their capacity or willingness to trade such investments may increase the Fund’s exposure to this risk. The debt market has experienced considerable growth, and financial institutions making markets in instruments purchased and sold by the Fund (e.g., bond dealers) have been subject to increased regulation. The impact of that growth and regulation on the ability and willingness of financial institutions to engage in trading or “making a market” in such instruments remains unsettled. Certain types of investments, such as lower-rated securities or those that are purchased and sold in over-the-counter markets, may be especially subject to liquidity risk. Securities or other assets in which the Fund invests may be traded in the over-the-counter market rather than on an exchange and therefore may be more difficult to purchase or sell at a fair price, which may have a negative impact on the Fund’s performance. Market participants attempting to sell the same or a similar instrument at the same time as the Fund could exacerbate the Fund’s exposure to liquidity risk. The Fund may have to accept a lower selling price for the holding, sell other liquid or more liquid investments that it might otherwise prefer to hold (thereby increasing the proportion of the Fund’s investments in less liquid or illiquid securities), or forego another more appealing investment opportunity. Certain investments that were liquid when purchased by the Fund may later become illiquid, particularly in times of overall economic distress. Changing regulatory, market or other conditions or environments (for example, the interest rate or credit environments) may also adversely affect the liquidity and the price of the Fund's investments. Judgment plays a larger role in valuing illiquid or less liquid investments as compared to valuing liquid or more liquid investments. Price volatility may be higher for illiquid or less liquid investments as a result of, for example, the relatively less frequent pricing of such securities (as compared to liquid or more liquid investments). Generally, the less liquid the market at the time the Fund sells a portfolio investment, the greater the risk of loss or decline of value to the Fund. Overall market liquidity and other factors can lead to an increase in redemptions, which may negatively impact Fund performance and NAV, including, for example, if the Fund is forced to sell investments in a down market. The municipal securities market is an over-the-counter market, which means that the Fund purchases and sells investments through municipal bond dealers. The Fund’s ability to sell investments held in its portfolio is dependent on the willingness and ability of market participants to provide bids that, in the view of portfolio management, reflect current market prices. Adverse market conditions could result in a lack of liquidity by reducing the number of ready buyers. 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. Municipal Securities Risk. Municipal securities are debt obligations generally issued to obtain funds for various public purposes, including general financing for state and local governments, or financing for a specific project or public facility, and include obligations of the governments of the U.S. territories, commonwealths and possessions such as Guam, Puerto Rico and the U.S. Virgin Islands to the extent such obligations are exempt from state and U.S. federal income taxes. The value of municipal securities can be significantly affected by actual or expected political and legislative changes at the federal or state level. Municipal securities may be fully or partially backed by the taxing authority of the local government, by the credit of a private issuer, by the current or anticipated revenues from a specific project or specific assets or by domestic or foreign entities providing credit support, such as letters of credit, guarantees or insurance, and are generally classified into general obligation bonds and special revenue obligations. Because many municipal securities are issued to finance projects in sectors such as education, health care, transportation and utilities, conditions in those sectors can affect the overall municipal market. Issuers in a state, territory, commonwealth or possession in which the Fund invests may experience significant financial difficulties for various reasons, including as the result of events that cannot be reasonably anticipated or controlled such as social conflict or unrest, labor disruption and natural disasters. Such financial difficulties may lead to credit rating downgrades of such issuers which in turn, could affect the market values and marketability of many or all municipal obligations of issuers in such state, territory, commonwealth or possession. The value of the Fund’s shares will be negatively impacted to the extent it invests in such securities. The Fund’s annual and semiannual reports show the Fund’s investment exposures at a point in time. The risk of investing in the Fund is directly correlated to the Fund’s investment exposures. Securities issued by a particular state and its instrumentalities are subject to the risk of unfavorable developments in such state. A municipal security can be significantly affected by adverse tax, legislative, regulatory, demographic or political changes as well as changes in a particular state's (state and its instrumentalities) financial, economic or other condition and prospects. 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. Prepayment and Extension Risk. Prepayment and extension risk is the risk that a bond or other security or investment might, in the case of prepayment risk, be called or otherwise converted, prepaid or redeemed before maturity and, in the case of extension risk, that the investment might not be called as expected. In the case of prepayment risk, if the investment is converted, prepaid or redeemed before maturity, the portfolio managers may not be able to invest the proceeds in other investments providing as high a level of income, resulting in a reduced yield to the Fund. In the case of mortgage- or other asset-backed securities, as interest rates decrease or spreads narrow, the likelihood of prepayment increases. Conversely, extension risk is the risk that an unexpected rise in interest rates will extend the life of a mortgage- or asset-backed security beyond the prepayment time. If the Fund’s investments are locked in at a lower interest rate for a longer period of time, the portfolio managers may be unable to capitalize on securities with higher interest rates or wider spreads. Reinvestment Risk. Reinvestment risk is the risk that the Fund will not be able to reinvest income or principal at the same return it is currently earning. Sector Risk. At times, the Fund may have a significant portion of its assets invested in securities of companies conducting business within one or more economic sectors. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly the Fund invests, the more it spreads risk and potentially reduces the risks of loss and volatility. Tax Risk. Municipal securities generally pay interest that, in the opinion of bond counsel, is free from U.S. federal income tax (and in most cases, the U.S. federal alternative minimum tax). A portion of the Fund’s income from such bonds may be taxable to shareholders subject to the U.S. federal alternative minimum tax. Income from tax-exempt municipal obligations could be declared taxable, possibly retroactively, because of unfavorable changes in tax laws, adverse interpretations by the Internal Revenue Service, the non-compliant conduct of a bond issuer or under other circumstances. In such event, then the value of the security would likely fall and, as a shareholder of the Fund, you may be required to file an amended tax return and pay additional taxes.
Risk Lose Money [Text]	rr_RiskLoseMoney	There is no assurance that the Fund will achieve its investment objective and you may lose money.
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.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	<b>Non-Diversified Fund Risk.</b> 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.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<b>Performance Information </b>
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 A shares (without applicable sales charges and adjusted to reflect the higher class-related operating expenses of such share classes, where applicable) for periods prior to its inception date. Share classes with expenses that are higher than Class A shares will have performance that is lower than Class A shares (without sales charges). 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 columbiathreadneedleus.com.
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	columbiathreadneedleus.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	<b>The Fund’s past performance (before and after taxes) is no guarantee of how the Fund will perform in the future.</b>
Bar Chart [Heading]	rr_BarChartHeading	<b>Year by Year Total Return (%) <br/>as of December 31 Each Year</b>
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                            2nd Quarter 2016                             2.89% Worst                         4th Quarter 2016                            -4.20%
Performance Table Heading	rr_PerformanceTableHeading	<b>Average Annual Total Returns After Applicable Sales Charges (for periods ended December 31, 2017)</b>
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 U.S. Social Bond Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	3.00%
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	0.75%	[1]
Management fees	rr_ManagementFeesOverAssets	0.48%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	0.47%	[2]
Total annual Fund operating expenses	rr_ExpensesOverAssets	1.20%
Less: Fee waivers and/or expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.50%)	[3]
Total annual Fund operating expenses after fee waivers and/or expense reimbursements	rr_NetExpensesOverAssets	0.70%
Expenses Deferred Charges [Text Block]	rr_ExpensesDeferredChargesTextBlock	This charge is imposed on certain investments of $500,000 or more redeemed within 12 months after purchase, with certain limited exceptions.
1 year	rr_ExpenseExampleYear01	$ 369
3 years	rr_ExpenseExampleYear03	621
5 years	rr_ExpenseExampleYear05	893
10 years	rr_ExpenseExampleYear10	1,668
1 year	rr_ExpenseExampleNoRedemptionYear01	369
3 years	rr_ExpenseExampleNoRedemptionYear03	621
5 years	rr_ExpenseExampleNoRedemptionYear05	893
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 1,668
2016	rr_AnnualReturn2016	(0.21%)	[4]
2017	rr_AnnualReturn2017	5.99%	[4]
Year to Date Return, Label	rr_YearToDateReturnLabel	Year to Date return
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Sep. 30, 2018
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	(0.91%)
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2016
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	2.89%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2016
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(4.20%)
1 Year	rr_AverageAnnualReturnYear01	2.76%
Life of Fund	rr_AverageAnnualReturnSinceInception	1.53%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 26, 2015
Columbia U.S. Social Bond 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	0.48%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.47%	[2]
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.95%
Less: Fee waivers and/or expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.50%)	[3]
Total annual Fund operating expenses after fee waivers and/or expense reimbursements	rr_NetExpensesOverAssets	0.45%
1 year	rr_ExpenseExampleYear01	$ 46
3 years	rr_ExpenseExampleYear03	253
5 years	rr_ExpenseExampleYear05	477
10 years	rr_ExpenseExampleYear10	1,121
1 year	rr_ExpenseExampleNoRedemptionYear01	46
3 years	rr_ExpenseExampleNoRedemptionYear03	253
5 years	rr_ExpenseExampleNoRedemptionYear05	477
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 1,121
1 Year	rr_AverageAnnualReturnYear01	6.25%
Life of Fund	rr_AverageAnnualReturnSinceInception	2.91%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 26, 2015
Columbia U.S. Social Bond 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%	[5]
Management fees	rr_ManagementFeesOverAssets	0.48%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses	rr_OtherExpensesOverAssets	0.47%	[2]
Total annual Fund operating expenses	rr_ExpensesOverAssets	1.95%
Less: Fee waivers and/or expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.50%)	[3]
Total annual Fund operating expenses after fee waivers and/or expense reimbursements	rr_NetExpensesOverAssets	1.45%
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	$ 248
3 years	rr_ExpenseExampleYear03	564
5 years	rr_ExpenseExampleYear05	1,006
10 years	rr_ExpenseExampleYear10	2,234
1 year	rr_ExpenseExampleNoRedemptionYear01	148
3 years	rr_ExpenseExampleNoRedemptionYear03	564
5 years	rr_ExpenseExampleNoRedemptionYear05	1,006
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 2,234
1 Year	rr_AverageAnnualReturnYear01	4.31%
Life of Fund	rr_AverageAnnualReturnSinceInception	1.92%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 26, 2015
Columbia U.S. Social Bond 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	0.48%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.47%	[2]
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.95%
Less: Fee waivers and/or expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.50%)	[3]
Total annual Fund operating expenses after fee waivers and/or expense reimbursements	rr_NetExpensesOverAssets	0.45%
1 year	rr_ExpenseExampleYear01	$ 46
3 years	rr_ExpenseExampleYear03	253
5 years	rr_ExpenseExampleYear05	477
10 years	rr_ExpenseExampleYear10	1,121
1 year	rr_ExpenseExampleNoRedemptionYear01	46
3 years	rr_ExpenseExampleNoRedemptionYear03	253
5 years	rr_ExpenseExampleNoRedemptionYear05	477
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 1,121
1 Year	rr_AverageAnnualReturnYear01	6.25%
Life of Fund	rr_AverageAnnualReturnSinceInception	2.91%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 26, 2015
Columbia U.S. Social Bond 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	0.48%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.49%	[2]
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.97%
Less: Fee waivers and/or expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.53%)	[3]
Total annual Fund operating expenses after fee waivers and/or expense reimbursements	rr_NetExpensesOverAssets	0.44%
1 year	rr_ExpenseExampleYear01	$ 45
3 years	rr_ExpenseExampleYear03	256
5 years	rr_ExpenseExampleYear05	485
10 years	rr_ExpenseExampleYear10	1,141
1 year	rr_ExpenseExampleNoRedemptionYear01	45
3 years	rr_ExpenseExampleNoRedemptionYear03	256
5 years	rr_ExpenseExampleNoRedemptionYear05	485
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 1,141
1 Year	rr_AverageAnnualReturnYear01	6.26%
Life of Fund	rr_AverageAnnualReturnSinceInception	2.89%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 26, 2015
Columbia U.S. Social Bond 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	0.48%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.44%	[2]
Total annual Fund operating expenses	rr_ExpensesOverAssets	0.92%
Less: Fee waivers and/or expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.51%)	[3]
Total annual Fund operating expenses after fee waivers and/or expense reimbursements	rr_NetExpensesOverAssets	0.41%
1 year	rr_ExpenseExampleYear01	$ 42
3 years	rr_ExpenseExampleYear03	242
5 years	rr_ExpenseExampleYear05	459
10 years	rr_ExpenseExampleYear10	1,084
1 year	rr_ExpenseExampleNoRedemptionYear01	42
3 years	rr_ExpenseExampleNoRedemptionYear03	242
5 years	rr_ExpenseExampleNoRedemptionYear05	459
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 1,084
1 Year	rr_AverageAnnualReturnYear01	6.21%
Life of Fund	rr_AverageAnnualReturnSinceInception	2.73%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 01, 2017
Columbia U.S. Social Bond Fund | returns after taxes on distributions | Class A
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	2.76%
Life of Fund	rr_AverageAnnualReturnSinceInception	1.53%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 26, 2015
Columbia U.S. Social Bond Fund | returns after taxes on distributions and sale of Fund shares | Class A
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	2.54%
Life of Fund	rr_AverageAnnualReturnSinceInception	1.58%
Share Class Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 26, 2015
Columbia U.S. Social Bond Fund | Bloomberg Barclays Municipal Bond Index (reflects no deductions for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	5.45%
Life of Fund	rr_AverageAnnualReturnSinceInception	2.86%

[1] This charge is imposed on certain investments of $500,000 or more redeemed within 12 months after purchase, with certain limited exceptions.

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

[3] Columbia Management Investment Advisers, LLC and certain of its affiliates have contractually agreed to waive fees and/or to reimburse expenses (excluding transaction costs and certain other investment related expenses, interest, taxes, acquired fund fees and expenses, and infrequent and/or unusual expenses) through November 30, 2019, unless sooner terminated at the sole discretion of the Fund’s Board of Trustees (the Board). Under this agreement, the Fund’s net operating expenses, subject to applicable exclusions, will not exceed the annual rates of 0.70% for Class A, 0.45% for Class Adv, 1.45% for Class C, 0.45% for Class Inst, 0.44% for Class Inst2 and 0.41% for Class Inst3. The fee waivers and/or expense reimbursements shown in the table for Class Inst2 also reflect the contractual agreement of the Fund’s transfer agent to waive fees and/or to reimburse expenses through November 30, 2019, unless sooner terminated at the sole discretion of the Fund’s Board, so that the Fund’s transfer agency fees do not exceed the annual rate of 0.04% for Class Inst2.

[4] Year to Date return as of September 30, 2018: -0.91%

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