Shareholder Report

12 Months Ended

Jul. 31, 2024

USD ($)

Holding

Shareholder Report [Line Items]

Document Type

N-CSR

Amendment Flag

false

Registrant Name

Columbia Funds Series Trust I

Entity Central Index Key

0000773757

Entity Investment Company Type

N-1A

Document Period End Date

Jul. 31, 2024

Columbia Oregon Intermediate Municipal Bond Fund Class A

Shareholder Report [Line Items]

Fund Name

Columbia Oregon Intermediate Municipal Bond Fund

Class Name

Class A

Trading Symbol

COEAX

Annual or Semi-Annual Statement [Text Block]

This annual shareholder report contains important information about Columbia Oregon Intermediate Municipal Bond Fund (the Fund) for the period of August 1, 2023 to July 31, 2024.

Shareholder Report Annual or Semi-Annual

annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

Additional Information Phone Number

1-800-345-6611

Additional Information Website

columbiathreadneedleus.com/resources/literature

Expenses [Text Block]

What were the Fund costs for the reporting period?

(Based on a hypothetical $10,000 investment)

Class	Cost of a $10,000 investment	Cost paid as a percentage of a $10,000 investment
Class A	$82	0.81%

Expenses Paid, Amount

$ 82

Expense Ratio, Percent

0.81%

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

The performance of Class A shares for the period presented is shown in the Average Annual Total Returns table.

Top Performance Contributors

Allocations | Positive contributions to the Fund’s performance relative to the benchmark were driven by a modest overweight allocation to BB bonds, an underweight to AAA bonds, overweights to bonds less than 2 years to maturity and longer than 17-years to maturity, and an underweight to state general obligation (GO) bonds.

Security selection | Selection in bonds rated AA, in bonds 6-17 years to maturity and in local and state GO bonds added to performance.

Top Performance Detractors

Allocations | The Fund’s underweight to A and BBB bonds, an overweight to AA bonds, an underweight to prepay gas bonds, and an overweight to local GO bonds detracted from relative performance.

Security selection | Selection in single-A bonds, bonds 4-6 years to maturity and housing bonds detracted from performance.

Performance Past Does Not Indicate Future [Text]

Past performance does not guarantee future performance.

Line Graph [Table Text Block]

Average Annual Return [Table Text Block]

Average Annual Total Returns (%)	1 year	5 years	10 years
Class A (excluding sales charges) (a)	2.59	0.48	1.48
Class A (including sales charges) (a)	(0.52)	(0.13)	1.18
Bloomberg 3-15 Year Blend Municipal Bond Index	3.14	1.17	2.26
Bloomberg Municipal Bond Index	3.74	1.18	2.47

(a) Effective August 1, 2024, the Fund compares its performance to the Bloomberg Municipal Bond Index, a broad-based performance index that meets new regulatory requirements. The Fund’s performance is also compared to its prior benchmark, which more closely represents the market sectors and/or asset classes in which the Fund primarily invests.

No Deduction of Taxes [Text Block]

Performance does not reflect the deduction of taxes that a shareholder may pay on fund distributions or on the redemptions of fund shares.

Material Change Date

Aug. 01, 2024

Updated Performance Information Location [Text Block]

Visit columbiathreadneedleus.com/investment-products/mutual-funds for more recent performance information.

Net Assets

$ 304,334,086

Holdings Count | Holding

202

Advisory Fees Paid, Amount

$ 1,400,310

Investment Company, Portfolio Turnover

13.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$304,334,086
Total number of portfolio holdings	202
Management services fees (represents 0.47% of Fund average net assets)	$1,400,310
Portfolio turnover for the reporting period	13%

Holdings [Text Block]

Graphical Representation of Fund Holdings

The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.

Top Holdings

Oregon Health & Science University 07/01/2034 5.000%	2.5%
City of Portland Water System 04/01/2030 4.000%	2.5%
Tri-County Metropolitan Transportation District of Oregon 10/01/2032 5.000%	2.4%
Oregon Health & Science University 07/01/2032 5.000%	1.9%
State of Oregon Department of Transportation 11/15/2037 5.000%	1.8%
Puerto Rico Public Finance Corp. 08/01/2026 6.000%	1.7%
Port of Portland 07/01/2039 4.000%	1.6%
Washington Clackamas & Yamhill Counties School District No. 88J 06/15/2031 5.000%	1.5%
Port of Portland Airport 07/01/2042 5.250%	1.4%
State of Oregon Department of Transportation 11/15/2026 5.000%	1.4%

Asset Categories

Credit Quality

Credit Quality Explanation [Text Block]

Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.

Largest Holdings [Text Block]

Top Holdings

Oregon Health & Science University 07/01/2034 5.000%	2.5%
City of Portland Water System 04/01/2030 4.000%	2.5%
Tri-County Metropolitan Transportation District of Oregon 10/01/2032 5.000%	2.4%
Oregon Health & Science University 07/01/2032 5.000%	1.9%
State of Oregon Department of Transportation 11/15/2037 5.000%	1.8%
Puerto Rico Public Finance Corp. 08/01/2026 6.000%	1.7%
Port of Portland 07/01/2039 4.000%	1.6%
Washington Clackamas & Yamhill Counties School District No. 88J 06/15/2031 5.000%	1.5%
Port of Portland Airport 07/01/2042 5.250%	1.4%
State of Oregon Department of Transportation 11/15/2026 5.000%	1.4%

Material Fund Change [Text Block]

Certain Fund Changes

This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at columbiathreadneedleus.com/resources/literature or upon request at 1-800-345-6611.

On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates. In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally. These changes became effective on August 1, 2024.

Material Fund Change Strategies [Text Block]

On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates.

Material Fund Change Risks Change [Text Block]

In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally.

Summary of Change Legend [Text Block]

This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at columbiathreadneedleus.com/resources/literature or upon request at 1-800-345-6611.

Updated Prospectus Phone Number

1-800-345-6611

Updated Prospectus Web Address

columbiathreadneedleus.com/resources/literature

Columbia Oregon Intermediate Municipal Bond Fund Advisor Class

Shareholder Report [Line Items]

Fund Name

Columbia Oregon Intermediate Municipal Bond Fund

Class Name

Advisor Class

Trading Symbol

CORMX

Annual or Semi-Annual Statement [Text Block]

This annual shareholder report contains important information about Columbia Oregon Intermediate Municipal Bond Fund (the Fund) for the period of August 1, 2023 to July 31, 2024.

Shareholder Report Annual or Semi-Annual

annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

Additional Information Phone Number

1-800-345-6611

Additional Information Website

columbiathreadneedleus.com/resources/literature

Expenses [Text Block]

What were the Fund costs for the reporting period?

(Based on a hypothetical $10,000 investment)

Class	Cost of a $10,000 investment	Cost paid as a percentage of a $10,000 investment
Advisor Class	$57	0.56%

Expenses Paid, Amount

$ 57

Expense Ratio, Percent

0.56%

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

The performance of Advisor Class shares for the period presented is shown in the Average Annual Total Returns table.

Top Performance Contributors

Allocations | Positive contributions to the Fund’s performance relative to the benchmark were driven by a modest overweight allocation to BB bonds, an underweight to AAA bonds, overweights to bonds less than 2 years to maturity and longer than 17-years to maturity, and an underweight to state general obligation (GO) bonds.

Security selection | Selection in bonds rated AA, in bonds 6-17 years to maturity and in local and state GO bonds added to performance.

Top Performance Detractors

Allocations | The Fund’s underweight to A and BBB bonds, an overweight to AA bonds, an underweight to prepay gas bonds, and an overweight to local GO bonds detracted from relative performance.

Security selection | Selection in single-A bonds, bonds 4-6 years to maturity and housing bonds detracted from performance.

Performance Past Does Not Indicate Future [Text]

Past performance does not guarantee future performance.

Line Graph [Table Text Block]

Average Annual Return [Table Text Block]

Average Annual Total Returns (%)	1 year	5 years	10 years
Advisor Class (a)	2.93	0.75	1.76
Bloomberg 3-15 Year Blend Municipal Bond Index	3.14	1.17	2.26
Bloomberg Municipal Bond Index	3.74	1.18	2.47

(a) Effective August 1, 2024, the Fund compares its performance to the Bloomberg Municipal Bond Index, a broad-based performance index that meets new regulatory requirements. The Fund’s performance is also compared to its prior benchmark, which more closely represents the market sectors and/or asset classes in which the Fund primarily invests.

No Deduction of Taxes [Text Block]

Performance does not reflect the deduction of taxes that a shareholder may pay on fund distributions or on the redemptions of fund shares.

Material Change Date

Aug. 01, 2024

Updated Performance Information Location [Text Block]

Visit columbiathreadneedleus.com/investment-products/mutual-funds for more recent performance information.

Net Assets

$ 304,334,086

Holdings Count | Holding

202

Advisory Fees Paid, Amount

$ 1,400,310

Investment Company, Portfolio Turnover

13.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$304,334,086
Total number of portfolio holdings	202
Management services fees (represents 0.47% of Fund average net assets)	$1,400,310
Portfolio turnover for the reporting period	13%

Holdings [Text Block]

Graphical Representation of Fund Holdings

The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.

Top Holdings

Oregon Health & Science University 07/01/2034 5.000%	2.5%
City of Portland Water System 04/01/2030 4.000%	2.5%
Tri-County Metropolitan Transportation District of Oregon 10/01/2032 5.000%	2.4%
Oregon Health & Science University 07/01/2032 5.000%	1.9%
State of Oregon Department of Transportation 11/15/2037 5.000%	1.8%
Puerto Rico Public Finance Corp. 08/01/2026 6.000%	1.7%
Port of Portland 07/01/2039 4.000%	1.6%
Washington Clackamas & Yamhill Counties School District No. 88J 06/15/2031 5.000%	1.5%
Port of Portland Airport 07/01/2042 5.250%	1.4%
State of Oregon Department of Transportation 11/15/2026 5.000%	1.4%

Asset Categories

Credit Quality

Credit Quality Explanation [Text Block]

Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.

Largest Holdings [Text Block]

Top Holdings

Oregon Health & Science University 07/01/2034 5.000%	2.5%
City of Portland Water System 04/01/2030 4.000%	2.5%
Tri-County Metropolitan Transportation District of Oregon 10/01/2032 5.000%	2.4%
Oregon Health & Science University 07/01/2032 5.000%	1.9%
State of Oregon Department of Transportation 11/15/2037 5.000%	1.8%
Puerto Rico Public Finance Corp. 08/01/2026 6.000%	1.7%
Port of Portland 07/01/2039 4.000%	1.6%
Washington Clackamas & Yamhill Counties School District No. 88J 06/15/2031 5.000%	1.5%
Port of Portland Airport 07/01/2042 5.250%	1.4%
State of Oregon Department of Transportation 11/15/2026 5.000%	1.4%

Material Fund Change [Text Block]

Certain Fund Changes

This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at columbiathreadneedleus.com/resources/literature or upon request at 1-800-345-6611.

On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates. In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally. These changes became effective on August 1, 2024.

Material Fund Change Strategies [Text Block]

On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates.

Material Fund Change Risks Change [Text Block]

In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally.

Summary of Change Legend [Text Block]

This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at columbiathreadneedleus.com/resources/literature or upon request at 1-800-345-6611.

Updated Prospectus Phone Number

1-800-345-6611

Updated Prospectus Web Address

columbiathreadneedleus.com/resources/literature

Columbia Oregon Intermediate Municipal Bond Fund Institutional Class

Shareholder Report [Line Items]

Fund Name

Columbia Oregon Intermediate Municipal Bond Fund

Class Name

Institutional Class

Trading Symbol

CMBFX

Annual or Semi-Annual Statement [Text Block]

This annual shareholder report contains important information about Columbia Oregon Intermediate Municipal Bond Fund (the Fund) for the period of August 1, 2023 to July 31, 2024.

Shareholder Report Annual or Semi-Annual

annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

Additional Information Phone Number

1-800-345-6611

Additional Information Website

columbiathreadneedleus.com/resources/literature

Expenses [Text Block]

What were the Fund costs for the reporting period?

(Based on a hypothetical $10,000 investment)

Class	Cost of a $10,000 investment	Cost paid as a percentage of a $10,000 investment
Institutional Class	$57	0.56%

Expenses Paid, Amount

$ 57

Expense Ratio, Percent

0.56%

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

The performance of Institutional Class shares for the period presented is shown in the Average Annual Total Returns table.

Top Performance Contributors

Allocations | Positive contributions to the Fund’s performance relative to the benchmark were driven by a modest overweight allocation to BB bonds, an underweight to AAA bonds, overweights to bonds less than 2 years to maturity and longer than 17-years to maturity, and an underweight to state general obligation (GO) bonds.

Security selection | Selection in bonds rated AA, in bonds 6-17 years to maturity and in local and state GO bonds added to performance.

Top Performance Detractors

Allocations | The Fund’s underweight to A and BBB bonds, an overweight to AA bonds, an underweight to prepay gas bonds, and an overweight to local GO bonds detracted from relative performance.

Security selection | Selection in single-A bonds, bonds 4-6 years to maturity and housing bonds detracted from performance.

Performance Past Does Not Indicate Future [Text]

Past performance does not guarantee future performance.

Line Graph [Table Text Block]

Average Annual Return [Table Text Block]

Average Annual Total Returns (%)	1 year	5 years	10 years
Institutional Class (a)	2.84	0.73	1.74
Bloomberg 3-15 Year Blend Municipal Bond Index	3.14	1.17	2.26
Bloomberg Municipal Bond Index	3.74	1.18	2.47

(a) Effective August 1, 2024, the Fund compares its performance to the Bloomberg Municipal Bond Index, a broad-based performance index that meets new regulatory requirements. The Fund’s performance is also compared to its prior benchmark, which more closely represents the market sectors and/or asset classes in which the Fund primarily invests.

No Deduction of Taxes [Text Block]

Performance does not reflect the deduction of taxes that a shareholder may pay on fund distributions or on the redemptions of fund shares.

Material Change Date

Aug. 01, 2024

Updated Performance Information Location [Text Block]

Visit columbiathreadneedleus.com/investment-products/mutual-funds for more recent performance information.

Net Assets

$ 304,334,086

Holdings Count | Holding

202

Advisory Fees Paid, Amount

$ 1,400,310

Investment Company, Portfolio Turnover

13.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$304,334,086
Total number of portfolio holdings	202
Management services fees (represents 0.47% of Fund average net assets)	$1,400,310
Portfolio turnover for the reporting period	13%

Holdings [Text Block]

Graphical Representation of Fund Holdings

The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.

Top Holdings

Oregon Health & Science University 07/01/2034 5.000%	2.5%
City of Portland Water System 04/01/2030 4.000%	2.5%
Tri-County Metropolitan Transportation District of Oregon 10/01/2032 5.000%	2.4%
Oregon Health & Science University 07/01/2032 5.000%	1.9%
State of Oregon Department of Transportation 11/15/2037 5.000%	1.8%
Puerto Rico Public Finance Corp. 08/01/2026 6.000%	1.7%
Port of Portland 07/01/2039 4.000%	1.6%
Washington Clackamas & Yamhill Counties School District No. 88J 06/15/2031 5.000%	1.5%
Port of Portland Airport 07/01/2042 5.250%	1.4%
State of Oregon Department of Transportation 11/15/2026 5.000%	1.4%

Asset Categories

Credit Quality

Credit Quality Explanation [Text Block]

Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.

Largest Holdings [Text Block]

Top Holdings

Oregon Health & Science University 07/01/2034 5.000%	2.5%
City of Portland Water System 04/01/2030 4.000%	2.5%
Tri-County Metropolitan Transportation District of Oregon 10/01/2032 5.000%	2.4%
Oregon Health & Science University 07/01/2032 5.000%	1.9%
State of Oregon Department of Transportation 11/15/2037 5.000%	1.8%
Puerto Rico Public Finance Corp. 08/01/2026 6.000%	1.7%
Port of Portland 07/01/2039 4.000%	1.6%
Washington Clackamas & Yamhill Counties School District No. 88J 06/15/2031 5.000%	1.5%
Port of Portland Airport 07/01/2042 5.250%	1.4%
State of Oregon Department of Transportation 11/15/2026 5.000%	1.4%

Material Fund Change [Text Block]

Certain Fund Changes

This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at columbiathreadneedleus.com/resources/literature or upon request at 1-800-345-6611.

On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates. In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally. These changes became effective on August 1, 2024.

Material Fund Change Strategies [Text Block]

On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates.

Material Fund Change Risks Change [Text Block]

In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally.

Summary of Change Legend [Text Block]

This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at columbiathreadneedleus.com/resources/literature or upon request at 1-800-345-6611.

Updated Prospectus Phone Number

1-800-345-6611

Updated Prospectus Web Address

columbiathreadneedleus.com/resources/literature

Columbia Oregon Intermediate Municipal Bond Fund Institutional 2 Class

Shareholder Report [Line Items]

Fund Name

Columbia Oregon Intermediate Municipal Bond Fund

Class Name

Institutional 2 Class

Trading Symbol

CODRX

Annual or Semi-Annual Statement [Text Block]

This annual shareholder report contains important information about Columbia Oregon Intermediate Municipal Bond Fund (the Fund) for the period of August 1, 2023 to July 31, 2024.

Shareholder Report Annual or Semi-Annual

annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

Additional Information Phone Number

1-800-345-6611

Additional Information Website

columbiathreadneedleus.com/resources/literature

Expenses [Text Block]

What were the Fund costs for the reporting period?

(Based on a hypothetical $10,000 investment)

Class	Cost of a $10,000 investment	Cost paid as a percentage of a $10,000 investment
Institutional 2 Class	$54	0.53%

Expenses Paid, Amount

$ 54

Expense Ratio, Percent

0.53%

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

The performance of Institutional 2 Class shares for the period presented is shown in the Average Annual Total Returns table.

Top Performance Contributors

Allocations | Positive contributions to the Fund’s performance relative to the benchmark were driven by a modest overweight allocation to BB bonds, an underweight to AAA bonds, overweights to bonds less than 2 years to maturity and longer than 17-years to maturity, and an underweight to state general obligation (GO) bonds.

Security selection | Selection in bonds rated AA, in bonds 6-17 years to maturity and in local and state GO bonds added to performance.

Top Performance Detractors

Allocations | The Fund’s underweight to A and BBB bonds, an overweight to AA bonds, an underweight to prepay gas bonds, and an overweight to local GO bonds detracted from relative performance.

Security selection | Selection in single-A bonds, bonds 4-6 years to maturity and housing bonds detracted from performance.

Performance Past Does Not Indicate Future [Text]

Past performance does not guarantee future performance.

Line Graph [Table Text Block]

Average Annual Return [Table Text Block]

Average Annual Total Returns (%)	1 year	5 years	10 years
Institutional 2 Class (a)	2.87	0.75	1.77
Bloomberg 3-15 Year Blend Municipal Bond Index	3.14	1.17	2.26
Bloomberg Municipal Bond Index	3.74	1.18	2.47

(a) Effective August 1, 2024, the Fund compares its performance to the Bloomberg Municipal Bond Index, a broad-based performance index that meets new regulatory requirements. The Fund’s performance is also compared to its prior benchmark, which more closely represents the market sectors and/or asset classes in which the Fund primarily invests.

No Deduction of Taxes [Text Block]

Performance does not reflect the deduction of taxes that a shareholder may pay on fund distributions or on the redemptions of fund shares.

Material Change Date

Aug. 01, 2024

Updated Performance Information Location [Text Block]

Visit columbiathreadneedleus.com/investment-products/mutual-funds for more recent performance information.

Net Assets

$ 304,334,086

Holdings Count | Holding

202

Advisory Fees Paid, Amount

$ 1,400,310

Investment Company, Portfolio Turnover

13.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$304,334,086
Total number of portfolio holdings	202
Management services fees (represents 0.47% of Fund average net assets)	$1,400,310
Portfolio turnover for the reporting period	13%

Holdings [Text Block]

Graphical Representation of Fund Holdings

The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.

Top Holdings

Oregon Health & Science University 07/01/2034 5.000%	2.5%
City of Portland Water System 04/01/2030 4.000%	2.5%
Tri-County Metropolitan Transportation District of Oregon 10/01/2032 5.000%	2.4%
Oregon Health & Science University 07/01/2032 5.000%	1.9%
State of Oregon Department of Transportation 11/15/2037 5.000%	1.8%
Puerto Rico Public Finance Corp. 08/01/2026 6.000%	1.7%
Port of Portland 07/01/2039 4.000%	1.6%
Washington Clackamas & Yamhill Counties School District No. 88J 06/15/2031 5.000%	1.5%
Port of Portland Airport 07/01/2042 5.250%	1.4%
State of Oregon Department of Transportation 11/15/2026 5.000%	1.4%

Asset Categories

Credit Quality

Credit Quality Explanation [Text Block]

Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.

Largest Holdings [Text Block]

Top Holdings

Oregon Health & Science University 07/01/2034 5.000%	2.5%
City of Portland Water System 04/01/2030 4.000%	2.5%
Tri-County Metropolitan Transportation District of Oregon 10/01/2032 5.000%	2.4%
Oregon Health & Science University 07/01/2032 5.000%	1.9%
State of Oregon Department of Transportation 11/15/2037 5.000%	1.8%
Puerto Rico Public Finance Corp. 08/01/2026 6.000%	1.7%
Port of Portland 07/01/2039 4.000%	1.6%
Washington Clackamas & Yamhill Counties School District No. 88J 06/15/2031 5.000%	1.5%
Port of Portland Airport 07/01/2042 5.250%	1.4%
State of Oregon Department of Transportation 11/15/2026 5.000%	1.4%

Material Fund Change [Text Block]

Certain Fund Changes

This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at columbiathreadneedleus.com/resources/literature or upon request at 1-800-345-6611.

On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates. In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally. These changes became effective on August 1, 2024.

Material Fund Change Strategies [Text Block]

On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates.

Material Fund Change Risks Change [Text Block]

In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally.

Summary of Change Legend [Text Block]

This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at columbiathreadneedleus.com/resources/literature or upon request at 1-800-345-6611.

Updated Prospectus Phone Number

1-800-345-6611

Updated Prospectus Web Address

columbiathreadneedleus.com/resources/literature

Columbia Oregon Intermediate Municipal Bond Fund Institutional 3 Class

Shareholder Report [Line Items]

Fund Name

Columbia Oregon Intermediate Municipal Bond Fund

Class Name

Institutional 3 Class

Trading Symbol

CORYX

Annual or Semi-Annual Statement [Text Block]

This annual shareholder report contains important information about Columbia Oregon Intermediate Municipal Bond Fund (the Fund) for the period of August 1, 2023 to July 31, 2024.

Shareholder Report Annual or Semi-Annual

annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at columbiathreadneedleus.com/resources/literature. You can also request more information by contacting us at 1-800-345-6611.

Additional Information Phone Number

1-800-345-6611

Additional Information Website

columbiathreadneedleus.com/resources/literature

Expenses [Text Block]

What were the Fund costs for the reporting period?

(Based on a hypothetical $10,000 investment)

Class	Cost of a $10,000 investment	Cost paid as a percentage of a $10,000 investment
Institutional 3 Class	$49	0.48%

Expenses Paid, Amount

$ 49

Expense Ratio, Percent

0.48%

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

The performance of Institutional 3 Class shares for the period presented is shown in the Average Annual Total Returns table.

Top Performance Contributors

Allocations | Positive contributions to the Fund’s performance relative to the benchmark were driven by a modest overweight allocation to BB bonds, an underweight to AAA bonds, overweights to bonds less than 2 years to maturity and longer than 17-years to maturity, and an underweight to state general obligation (GO) bonds.

Security selection | Selection in bonds rated AA, in bonds 6-17 years to maturity and in local and state GO bonds added to performance.

Top Performance Detractors

Allocations | The Fund’s underweight to A and BBB bonds, an overweight to AA bonds, an underweight to prepay gas bonds, and an overweight to local GO bonds detracted from relative performance.

Security selection | Selection in single-A bonds, bonds 4-6 years to maturity and housing bonds detracted from performance.

Performance Past Does Not Indicate Future [Text]

Past performance does not guarantee future performance.

Line Graph [Table Text Block]

Average Annual Return [Table Text Block]

Average Annual Total Returns (%)	1 year	5 years	10 years
Institutional 3 Class (a),(b)	3.01	0.82	1.80
Bloomberg 3-15 Year Blend Municipal Bond Index	3.14	1.17	2.26
Bloomberg Municipal Bond Index	3.74	1.18	2.47

(a)

The returns shown for periods prior to March 1, 2017 (including returns for the Life of the Fund, if shown, which are since Fund inception) include the returns of Institutional Class. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit columbiathreadneedleus.com/investor/investment-products/mutual-funds/appended-performance for more information.

(b)

Effective August 1, 2024, the Fund compares its performance to the Bloomberg Municipal Bond Index, a broad-based performance index that meets new regulatory requirements. The Fund’s performance is also compared to its prior benchmark, which more closely represents the market sectors and/or asset classes in which the Fund primarily invests.

No Deduction of Taxes [Text Block]

Performance does not reflect the deduction of taxes that a shareholder may pay on fund distributions or on the redemptions of fund shares.

Material Change Date

Aug. 01, 2024

Updated Performance Information Location [Text Block]

Visit columbiathreadneedleus.com/investment-products/mutual-funds for more recent performance information.

Net Assets

$ 304,334,086

Holdings Count | Holding

202

Advisory Fees Paid, Amount

$ 1,400,310

Investment Company, Portfolio Turnover

13.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$304,334,086
Total number of portfolio holdings	202
Management services fees (represents 0.47% of Fund average net assets)	$1,400,310
Portfolio turnover for the reporting period	13%

Holdings [Text Block]

Graphical Representation of Fund Holdings

The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.

Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.

Top Holdings

Oregon Health & Science University 07/01/2034 5.000%	2.5%
City of Portland Water System 04/01/2030 4.000%	2.5%
Tri-County Metropolitan Transportation District of Oregon 10/01/2032 5.000%	2.4%
Oregon Health & Science University 07/01/2032 5.000%	1.9%
State of Oregon Department of Transportation 11/15/2037 5.000%	1.8%
Puerto Rico Public Finance Corp. 08/01/2026 6.000%	1.7%
Port of Portland 07/01/2039 4.000%	1.6%
Washington Clackamas & Yamhill Counties School District No. 88J 06/15/2031 5.000%	1.5%
Port of Portland Airport 07/01/2042 5.250%	1.4%
State of Oregon Department of Transportation 11/15/2026 5.000%	1.4%

Asset Categories

Credit Quality

Credit Quality Explanation [Text Block]

Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.

Largest Holdings [Text Block]

Top Holdings

Oregon Health & Science University 07/01/2034 5.000%	2.5%
City of Portland Water System 04/01/2030 4.000%	2.5%
Tri-County Metropolitan Transportation District of Oregon 10/01/2032 5.000%	2.4%
Oregon Health & Science University 07/01/2032 5.000%	1.9%
State of Oregon Department of Transportation 11/15/2037 5.000%	1.8%
Puerto Rico Public Finance Corp. 08/01/2026 6.000%	1.7%
Port of Portland 07/01/2039 4.000%	1.6%
Washington Clackamas & Yamhill Counties School District No. 88J 06/15/2031 5.000%	1.5%
Port of Portland Airport 07/01/2042 5.250%	1.4%
State of Oregon Department of Transportation 11/15/2026 5.000%	1.4%

Material Fund Change [Text Block]

Certain Fund Changes

This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at columbiathreadneedleus.com/resources/literature or upon request at 1-800-345-6611.

On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates. In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally. These changes became effective on August 1, 2024.

Material Fund Change Strategies [Text Block]

On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates.

Material Fund Change Risks Change [Text Block]

In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally.

Summary of Change Legend [Text Block]

This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at columbiathreadneedleus.com/resources/literature or upon request at 1-800-345-6611.

Updated Prospectus Phone Number

1-800-345-6611

Updated Prospectus Web Address

columbiathreadneedleus.com/resources/literature