Shareholder Report

6 Months Ended

Jun. 30, 2024

USD ($)

Holding

Shareholder Report [Line Items]

Document Type

N-CSRS

Amendment Flag

false

Registrant Name

Columbia Acorn Trust

Entity Central Index Key

0000002110

Entity Investment Company Type

N-1A

Document Period End Date

Jun. 30, 2024

Columbia Acorn® Fund Class A

Shareholder Report [Line Items]

Fund Name

Columbia Acorn® Fund

Class Name

Class A

Trading Symbol

LACAX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn® Fund (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Class A	$54	1.08%

Expenses Paid, Amount

$ 54

Expense Ratio, Percent

1.08%

Net Assets

$ 2,664,444,631

Holdings Count | Holding

103

Investment Company, Portfolio Turnover

40.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$2,664,444,631
Total number of portfolio holdings	103
Portfolio turnover for the reporting period	40%

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.

Top Holdings

Churchill Downs, Inc.	3.0%
SPX Technologies, Inc.	2.4%
Bio-Techne Corp.	2.4%
Five Below, Inc.	2.3%
BJ's Wholesale Club Holdings, Inc.	2.1%
Parsons Corp.	2.1%
Natera, Inc.	2.0%
Colliers International Group, Inc.	2.0%
Ryan Specialty Holdings, Inc., Class A	2.0%
WillScot Mobile Mini Holdings Corp.	2.0%

Asset Categories

Equity Sector Allocation

Largest Holdings [Text Block]

Top Holdings

Churchill Downs, Inc.	3.0%
SPX Technologies, Inc.	2.4%
Bio-Techne Corp.	2.4%
Five Below, Inc.	2.3%
BJ's Wholesale Club Holdings, Inc.	2.1%
Parsons Corp.	2.1%
Natera, Inc.	2.0%
Colliers International Group, Inc.	2.0%
Ryan Specialty Holdings, Inc., Class A	2.0%
WillScot Mobile Mini Holdings Corp.	2.0%

Columbia Acorn® Fund Advisor Class

Shareholder Report [Line Items]

Fund Name

Columbia Acorn® Fund

Class Name

Advisor Class

Trading Symbol

CEARX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn® Fund (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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

olumbiathreadneedleus.com/resources/literature

Expenses [Text Block]

What were the Fund costs for the reporting period?

(Based on a hypothetical $10,000 investment)

Class	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Advisor Class	$42	0.83%

Expenses Paid, Amount

$ 42

Expense Ratio, Percent

0.83%

Net Assets

$ 2,664,444,631

Holdings Count | Holding

103

Investment Company, Portfolio Turnover

40.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$2,664,444,631
Total number of portfolio holdings	103
Portfolio turnover for the reporting period	40%

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.

Top Holdings

Churchill Downs, Inc.	3.0%
SPX Technologies, Inc.	2.4%
Bio-Techne Corp.	2.4%
Five Below, Inc.	2.3%
BJ's Wholesale Club Holdings, Inc.	2.1%
Parsons Corp.	2.1%
Natera, Inc.	2.0%
Colliers International Group, Inc.	2.0%
Ryan Specialty Holdings, Inc., Class A	2.0%
WillScot Mobile Mini Holdings Corp.	2.0%

Asset Categories

Equity Sector Allocation

Largest Holdings [Text Block]

Top Holdings

Churchill Downs, Inc.	3.0%
SPX Technologies, Inc.	2.4%
Bio-Techne Corp.	2.4%
Five Below, Inc.	2.3%
BJ's Wholesale Club Holdings, Inc.	2.1%
Parsons Corp.	2.1%
Natera, Inc.	2.0%
Colliers International Group, Inc.	2.0%
Ryan Specialty Holdings, Inc., Class A	2.0%
WillScot Mobile Mini Holdings Corp.	2.0%

Columbia Acorn® Fund Class C

Shareholder Report [Line Items]

Fund Name

Columbia Acorn® Fund

Class Name

Class C

Trading Symbol

LIACX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn® Fund (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Class C	$92	1.83%

Expenses Paid, Amount

$ 92

Expense Ratio, Percent

1.83%

Net Assets

$ 2,664,444,631

Holdings Count | Holding

103

Investment Company, Portfolio Turnover

40.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$2,664,444,631
Total number of portfolio holdings	103
Portfolio turnover for the reporting period	40%

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.

Top Holdings

Churchill Downs, Inc.	3.0%
SPX Technologies, Inc.	2.4%
Bio-Techne Corp.	2.4%
Five Below, Inc.	2.3%
BJ's Wholesale Club Holdings, Inc.	2.1%
Parsons Corp.	2.1%
Natera, Inc.	2.0%
Colliers International Group, Inc.	2.0%
Ryan Specialty Holdings, Inc., Class A	2.0%
WillScot Mobile Mini Holdings Corp.	2.0%

Asset Categories

Equity Sector Allocation

Largest Holdings [Text Block]

Top Holdings

Churchill Downs, Inc.	3.0%
SPX Technologies, Inc.	2.4%
Bio-Techne Corp.	2.4%
Five Below, Inc.	2.3%
BJ's Wholesale Club Holdings, Inc.	2.1%
Parsons Corp.	2.1%
Natera, Inc.	2.0%
Colliers International Group, Inc.	2.0%
Ryan Specialty Holdings, Inc., Class A	2.0%
WillScot Mobile Mini Holdings Corp.	2.0%

Columbia Acorn® Fund Institutional Class

Shareholder Report [Line Items]

Fund Name

Columbia Acorn® Fund

Class Name

Institutional Class

Trading Symbol

ACRNX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn® Fund (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Institutional Class	$42	0.83%

Expenses Paid, Amount

$ 42

Expense Ratio, Percent

0.83%

Net Assets

$ 2,664,444,631

Holdings Count | Holding

103

Investment Company, Portfolio Turnover

40.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$2,664,444,631
Total number of portfolio holdings	103
Portfolio turnover for the reporting period	40%

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.

Top Holdings

Churchill Downs, Inc.	3.0%
SPX Technologies, Inc.	2.4%
Bio-Techne Corp.	2.4%
Five Below, Inc.	2.3%
BJ's Wholesale Club Holdings, Inc.	2.1%
Parsons Corp.	2.1%
Natera, Inc.	2.0%
Colliers International Group, Inc.	2.0%
Ryan Specialty Holdings, Inc., Class A	2.0%
WillScot Mobile Mini Holdings Corp.	2.0%

Asset Categories

Equity Sector Allocation

Largest Holdings [Text Block]

Top Holdings

Churchill Downs, Inc.	3.0%
SPX Technologies, Inc.	2.4%
Bio-Techne Corp.	2.4%
Five Below, Inc.	2.3%
BJ's Wholesale Club Holdings, Inc.	2.1%
Parsons Corp.	2.1%
Natera, Inc.	2.0%
Colliers International Group, Inc.	2.0%
Ryan Specialty Holdings, Inc., Class A	2.0%
WillScot Mobile Mini Holdings Corp.	2.0%

Columbia Acorn® Fund Institutional 2 Class

Shareholder Report [Line Items]

Fund Name

Columbia Acorn® Fund

Class Name

Institutional 2 Class

Trading Symbol

CRBRX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn® Fund (the Fund) for the period of January 1, 2024 to June 30, 2024

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Institutional 2 Class	$40	0.80%

Expenses Paid, Amount

$ 40

Expense Ratio, Percent

0.80%

Net Assets

$ 2,664,444,631

Holdings Count | Holding

103

Investment Company, Portfolio Turnover

40.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$2,664,444,631
Total number of portfolio holdings	103
Portfolio turnover for the reporting period	40%

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.

Top Holdings

Churchill Downs, Inc.	3.0%
SPX Technologies, Inc.	2.4%
Bio-Techne Corp.	2.4%
Five Below, Inc.	2.3%
BJ's Wholesale Club Holdings, Inc.	2.1%
Parsons Corp.	2.1%
Natera, Inc.	2.0%
Colliers International Group, Inc.	2.0%
Ryan Specialty Holdings, Inc., Class A	2.0%
WillScot Mobile Mini Holdings Corp.	2.0%

Asset Categories

Equity Sector Allocation

Largest Holdings [Text Block]

Top Holdings

Churchill Downs, Inc.	3.0%
SPX Technologies, Inc.	2.4%
Bio-Techne Corp.	2.4%
Five Below, Inc.	2.3%
BJ's Wholesale Club Holdings, Inc.	2.1%
Parsons Corp.	2.1%
Natera, Inc.	2.0%
Colliers International Group, Inc.	2.0%
Ryan Specialty Holdings, Inc., Class A	2.0%
WillScot Mobile Mini Holdings Corp.	2.0%

Columbia Acorn® Fund Institutional 3 Class

Shareholder Report [Line Items]

Fund Name

Columbia Acorn® Fund

Class Name

Institutional 3 Class

Trading Symbol

CRBYX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn® Fund (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Institutional 3 Class	$38	0.75%

Expenses Paid, Amount

$ 38

Expense Ratio, Percent

0.75%

Net Assets

$ 2,664,444,631

Holdings Count | Holding

103

Investment Company, Portfolio Turnover

40.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$2,664,444,631
Total number of portfolio holdings	103
Portfolio turnover for the reporting period	40%

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.

Top Holdings

Churchill Downs, Inc.	3.0%
SPX Technologies, Inc.	2.4%
Bio-Techne Corp.	2.4%
Five Below, Inc.	2.3%
BJ's Wholesale Club Holdings, Inc.	2.1%
Parsons Corp.	2.1%
Natera, Inc.	2.0%
Colliers International Group, Inc.	2.0%
Ryan Specialty Holdings, Inc., Class A	2.0%
WillScot Mobile Mini Holdings Corp.	2.0%

Asset Categories

Equity Sector Allocation

Largest Holdings [Text Block]

Top Holdings

Churchill Downs, Inc.	3.0%
SPX Technologies, Inc.	2.4%
Bio-Techne Corp.	2.4%
Five Below, Inc.	2.3%
BJ's Wholesale Club Holdings, Inc.	2.1%
Parsons Corp.	2.1%
Natera, Inc.	2.0%
Colliers International Group, Inc.	2.0%
Ryan Specialty Holdings, Inc., Class A	2.0%
WillScot Mobile Mini Holdings Corp.	2.0%

Columbia Acorn International® Class A

Shareholder Report [Line Items]

Fund Name

Columbia Acorn International®

Class Name

Class A

Trading Symbol

LAIAX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn International® (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Class A	$62	1.23%

Expenses Paid, Amount

$ 62

Expense Ratio, Percent

1.23%

Net Assets

$ 1,051,504,186

Holdings Count | Holding

77

Investment Company, Portfolio Turnover

5.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$1,051,504,186
Total number of portfolio holdings	77
Portfolio turnover for the reporting period	5%

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.

Top Holdings

Belimo Holding AG, Registered Shares	2.9%
Recruit Holdings Co., Ltd.	2.7%
Hexagon AB, Class B	2.4%
Intermediate Capital Group PLC	2.4%
Hypoport SE	2.3%
Auto Trader Group PLC	2.3%
Pro Medicus Ltd.	2.3%
Munters Group AB	2.3%
IMCD NV	2.2%
CCL Industries, Inc., Class B	2.1%

Equity Sector Allocation

Geographic Allocation

Largest Holdings [Text Block]

Top Holdings

Belimo Holding AG, Registered Shares	2.9%
Recruit Holdings Co., Ltd.	2.7%
Hexagon AB, Class B	2.4%
Intermediate Capital Group PLC	2.4%
Hypoport SE	2.3%
Auto Trader Group PLC	2.3%
Pro Medicus Ltd.	2.3%
Munters Group AB	2.3%
IMCD NV	2.2%
CCL Industries, Inc., Class B	2.1%

Columbia Acorn International® Advisor Class

Shareholder Report [Line Items]

Fund Name

Columbia Acorn International®

Class Name

Advisor Class

Trading Symbol

CCIRX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn International® (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Advisor Class	$49	0.98%

Expenses Paid, Amount

$ 49

Expense Ratio, Percent

0.98%

Net Assets

$ 1,051,504,186

Holdings Count | Holding

77

Investment Company, Portfolio Turnover

5.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$1,051,504,186
Total number of portfolio holdings	77
Portfolio turnover for the reporting period	5%

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.

Top Holdings

Belimo Holding AG, Registered Shares	2.9%
Recruit Holdings Co., Ltd.	2.7%
Hexagon AB, Class B	2.4%
Intermediate Capital Group PLC	2.4%
Hypoport SE	2.3%
Auto Trader Group PLC	2.3%
Pro Medicus Ltd.	2.3%
Munters Group AB	2.3%
IMCD NV	2.2%
CCL Industries, Inc., Class B	2.1%

Equity Sector Allocation

Geographic Allocation

Largest Holdings [Text Block]

Top Holdings

Belimo Holding AG, Registered Shares	2.9%
Recruit Holdings Co., Ltd.	2.7%
Hexagon AB, Class B	2.4%
Intermediate Capital Group PLC	2.4%
Hypoport SE	2.3%
Auto Trader Group PLC	2.3%
Pro Medicus Ltd.	2.3%
Munters Group AB	2.3%
IMCD NV	2.2%
CCL Industries, Inc., Class B	2.1%

Columbia Acorn International® Institutional Class

Shareholder Report [Line Items]

Fund Name

Columbia Acorn International®

Class Name

Institutional Class

Trading Symbol

ACINX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn International® (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Institutional Class	$49	0.98%

Expenses Paid, Amount

$ 49

Expense Ratio, Percent

0.98%

Net Assets

$ 1,051,504,186

Holdings Count | Holding

77

Investment Company, Portfolio Turnover

5.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$1,051,504,186
Total number of portfolio holdings	77
Portfolio turnover for the reporting period	5%

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.

Top Holdings

Belimo Holding AG, Registered Shares	2.9%
Recruit Holdings Co., Ltd.	2.7%
Hexagon AB, Class B	2.4%
Intermediate Capital Group PLC	2.4%
Hypoport SE	2.3%
Auto Trader Group PLC	2.3%
Pro Medicus Ltd.	2.3%
Munters Group AB	2.3%
IMCD NV	2.2%
CCL Industries, Inc., Class B	2.1%

Equity Sector Allocation

Geographic Allocation

Largest Holdings [Text Block]

Top Holdings

Belimo Holding AG, Registered Shares	2.9%
Recruit Holdings Co., Ltd.	2.7%
Hexagon AB, Class B	2.4%
Intermediate Capital Group PLC	2.4%
Hypoport SE	2.3%
Auto Trader Group PLC	2.3%
Pro Medicus Ltd.	2.3%
Munters Group AB	2.3%
IMCD NV	2.2%
CCL Industries, Inc., Class B	2.1%

Columbia Acorn International® Institutional 2 Class

Shareholder Report [Line Items]

Fund Name

Columbia Acorn International®

Class Name

Institutional 2 Class

Trading Symbol

CAIRX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn International® (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Institutional 2 Class	$46	0.92%

Expenses Paid, Amount

$ 46

Expense Ratio, Percent

0.92%

Net Assets

$ 1,051,504,186

Holdings Count | Holding

77

Investment Company, Portfolio Turnover

5.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$1,051,504,186
Total number of portfolio holdings	77
Portfolio turnover for the reporting period	5%

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.

Top Holdings

Belimo Holding AG, Registered Shares	2.9%
Recruit Holdings Co., Ltd.	2.7%
Hexagon AB, Class B	2.4%
Intermediate Capital Group PLC	2.4%
Hypoport SE	2.3%
Auto Trader Group PLC	2.3%
Pro Medicus Ltd.	2.3%
Munters Group AB	2.3%
IMCD NV	2.2%
CCL Industries, Inc., Class B	2.1%

Equity Sector Allocation

Geographic Allocation

Largest Holdings [Text Block]

Top Holdings

Belimo Holding AG, Registered Shares	2.9%
Recruit Holdings Co., Ltd.	2.7%
Hexagon AB, Class B	2.4%
Intermediate Capital Group PLC	2.4%
Hypoport SE	2.3%
Auto Trader Group PLC	2.3%
Pro Medicus Ltd.	2.3%
Munters Group AB	2.3%
IMCD NV	2.2%
CCL Industries, Inc., Class B	2.1%

Columbia Acorn International® Institutional 3 Class

Shareholder Report [Line Items]

Fund Name

Columbia Acorn International®

Class Name

Institutional 3 Class

Trading Symbol

CCYIX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn International® (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Institutional 3 Class	$44	0.88%

Expenses Paid, Amount

$ 44

Expense Ratio, Percent

0.88%

Net Assets

$ 1,051,504,186

Holdings Count | Holding

77

Investment Company, Portfolio Turnover

5.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$1,051,504,186
Total number of portfolio holdings	77
Portfolio turnover for the reporting period	5%

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.

Top Holdings

Belimo Holding AG, Registered Shares	2.9%
Recruit Holdings Co., Ltd.	2.7%
Hexagon AB, Class B	2.4%
Intermediate Capital Group PLC	2.4%
Hypoport SE	2.3%
Auto Trader Group PLC	2.3%
Pro Medicus Ltd.	2.3%
Munters Group AB	2.3%
IMCD NV	2.2%
CCL Industries, Inc., Class B	2.1%

Equity Sector Allocation

Geographic Allocation

Largest Holdings [Text Block]

Top Holdings

Belimo Holding AG, Registered Shares	2.9%
Recruit Holdings Co., Ltd.	2.7%
Hexagon AB, Class B	2.4%
Intermediate Capital Group PLC	2.4%
Hypoport SE	2.3%
Auto Trader Group PLC	2.3%
Pro Medicus Ltd.	2.3%
Munters Group AB	2.3%
IMCD NV	2.2%
CCL Industries, Inc., Class B	2.1%

Columbia Acorn International SelectSM Class A

Shareholder Report [Line Items]

Fund Name

Columbia Acorn International SelectSM

Class Name

Class A

Trading Symbol

LAFAX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn International SelectSM (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Class A	$62	1.23%

Expenses Paid, Amount

$ 62

Expense Ratio, Percent

1.23%

Net Assets

$ 214,450,418

Holdings Count | Holding

68

Investment Company, Portfolio Turnover

62.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$214,450,418
Total number of portfolio holdings	68
Portfolio turnover for the reporting period	62%

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.

Top Holdings

Novo Nordisk A/S	4.0%
Schneider Electric SE	3.1%
ASML Holding NV	3.0%
Renesas Electronics Corp.	2.8%
3i Group PLC	2.7%
Adidas AG	2.6%
Capcom Co., Ltd.	2.6%
Recruit Holdings Co., Ltd.	2.6%
Nestlé SA, Registered Shares	2.2%
Publicis Groupe SA	2.2%

Equity Sector Allocation

Geographic Allocation

Largest Holdings [Text Block]

Top Holdings

Novo Nordisk A/S	4.0%
Schneider Electric SE	3.1%
ASML Holding NV	3.0%
Renesas Electronics Corp.	2.8%
3i Group PLC	2.7%
Adidas AG	2.6%
Capcom Co., Ltd.	2.6%
Recruit Holdings Co., Ltd.	2.6%
Nestlé SA, Registered Shares	2.2%
Publicis Groupe SA	2.2%

Columbia Acorn International SelectSM Advisor Class

Shareholder Report [Line Items]

Fund Name

Columbia Acorn International SelectSM

Class Name

Advisor Class

Trading Symbol

CILRX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn International SelectSM (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Advisor Class	$50	0.98%

Expenses Paid, Amount

$ 50

Expense Ratio, Percent

0.98%

Net Assets

$ 214,450,418

Holdings Count | Holding

68

Investment Company, Portfolio Turnover

62.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$214,450,418
Total number of portfolio holdings	68
Portfolio turnover for the reporting period	62%

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.

Top Holdings

Novo Nordisk A/S	4.0%
Schneider Electric SE	3.1%
ASML Holding NV	3.0%
Renesas Electronics Corp.	2.8%
3i Group PLC	2.7%
Adidas AG	2.6%
Capcom Co., Ltd.	2.6%
Recruit Holdings Co., Ltd.	2.6%
Nestlé SA, Registered Shares	2.2%
Publicis Groupe SA	2.2%

Equity Sector Allocation

Geographic Allocation

Largest Holdings [Text Block]

Top Holdings

Novo Nordisk A/S	4.0%
Schneider Electric SE	3.1%
ASML Holding NV	3.0%
Renesas Electronics Corp.	2.8%
3i Group PLC	2.7%
Adidas AG	2.6%
Capcom Co., Ltd.	2.6%
Recruit Holdings Co., Ltd.	2.6%
Nestlé SA, Registered Shares	2.2%
Publicis Groupe SA	2.2%

Columbia Acorn International SelectSM Institutional Class

Shareholder Report [Line Items]

Fund Name

Columbia Acorn International SelectSM

Class Name

Institutional Class

Trading Symbol

ACFFX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn International SelectSM (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Institutional Class	$50	0.98%

Expenses Paid, Amount

$ 50

Expense Ratio, Percent

0.98%

Net Assets

$ 214,450,418

Holdings Count | Holding

68

Investment Company, Portfolio Turnover

62.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$214,450,418
Total number of portfolio holdings	68
Portfolio turnover for the reporting period	62%

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.

Top Holdings

Novo Nordisk A/S	4.0%
Schneider Electric SE	3.1%
ASML Holding NV	3.0%
Renesas Electronics Corp.	2.8%
3i Group PLC	2.7%
Adidas AG	2.6%
Capcom Co., Ltd.	2.6%
Recruit Holdings Co., Ltd.	2.6%
Nestlé SA, Registered Shares	2.2%
Publicis Groupe SA	2.2%

Equity Sector Allocation

Geographic Allocation

Largest Holdings [Text Block]

Top Holdings

Novo Nordisk A/S	4.0%
Schneider Electric SE	3.1%
ASML Holding NV	3.0%
Renesas Electronics Corp.	2.8%
3i Group PLC	2.7%
Adidas AG	2.6%
Capcom Co., Ltd.	2.6%
Recruit Holdings Co., Ltd.	2.6%
Nestlé SA, Registered Shares	2.2%
Publicis Groupe SA	2.2%

Columbia Acorn International SelectSM Institutional 2 Class

Shareholder Report [Line Items]

Fund Name

Columbia Acorn International SelectSM

Class Name

Institutional 2 Class

Trading Symbol

CRIRX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn International SelectSM (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Institutional 2 Class	$43	0.84%

Expenses Paid, Amount

$ 43

Expense Ratio, Percent

0.84%

Net Assets

$ 214,450,418

Holdings Count | Holding

68

Investment Company, Portfolio Turnover

62.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$214,450,418
Total number of portfolio holdings	68
Portfolio turnover for the reporting period	62%

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.

Top Holdings

Novo Nordisk A/S	4.0%
Schneider Electric SE	3.1%
ASML Holding NV	3.0%
Renesas Electronics Corp.	2.8%
3i Group PLC	2.7%
Adidas AG	2.6%
Capcom Co., Ltd.	2.6%
Recruit Holdings Co., Ltd.	2.6%
Nestlé SA, Registered Shares	2.2%
Publicis Groupe SA	2.2%

Equity Sector Allocation

Geographic Allocation

Largest Holdings [Text Block]

Top Holdings

Novo Nordisk A/S	4.0%
Schneider Electric SE	3.1%
ASML Holding NV	3.0%
Renesas Electronics Corp.	2.8%
3i Group PLC	2.7%
Adidas AG	2.6%
Capcom Co., Ltd.	2.6%
Recruit Holdings Co., Ltd.	2.6%
Nestlé SA, Registered Shares	2.2%
Publicis Groupe SA	2.2%

Columbia Acorn International SelectSM Institutional 3 Class

Shareholder Report [Line Items]

Fund Name

Columbia Acorn International SelectSM

Class Name

Institutional 3 Class

Trading Symbol

CSIRX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn International SelectSM (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Institutional 3 Class	$40	0.79%

Expenses Paid, Amount

$ 40

Expense Ratio, Percent

0.79%

Net Assets

$ 214,450,418

Holdings Count | Holding

68

Investment Company, Portfolio Turnover

62.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$214,450,418
Total number of portfolio holdings	68
Portfolio turnover for the reporting period	62%

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.

Top Holdings

Novo Nordisk A/S	4.0%
Schneider Electric SE	3.1%
ASML Holding NV	3.0%
Renesas Electronics Corp.	2.8%
3i Group PLC	2.7%
Adidas AG	2.6%
Capcom Co., Ltd.	2.6%
Recruit Holdings Co., Ltd.	2.6%
Nestlé SA, Registered Shares	2.2%
Publicis Groupe SA	2.2%

Equity Sector Allocation

Geographic Allocation

Largest Holdings [Text Block]

Top Holdings

Novo Nordisk A/S	4.0%
Schneider Electric SE	3.1%
ASML Holding NV	3.0%
Renesas Electronics Corp.	2.8%
3i Group PLC	2.7%
Adidas AG	2.6%
Capcom Co., Ltd.	2.6%
Recruit Holdings Co., Ltd.	2.6%
Nestlé SA, Registered Shares	2.2%
Publicis Groupe SA	2.2%

Columbia Thermostat FundSM Class A

Shareholder Report [Line Items]

Fund Name

Columbia Thermostat FundSM

Class Name

Class A

Trading Symbol

CTFAX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Thermostat FundSM (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

Semi - 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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Class A	$25	0.50%

Expenses Paid, Amount

$ 25

Expense Ratio, Percent

0.50%

Net Assets

$ 1,250,944,133

Holdings Count | Holding

13

Investment Company, Portfolio Turnover

62.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$1,250,944,133
Total number of portfolio holdings	13
Portfolio turnover for the reporting period	62%

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.

Top Holdings

Columbia Total Return Bond Fund, Institutional 3 Class	15.0%
Columbia Corporate Income Fund, Institutional 3 Class	12.0%
Columbia U.S. Treasury Index Fund, Institutional 3 Class	12.0%
Columbia Large Cap Enhanced Core Fund, Institutional 3 Class	10.1%
Columbia Contrarian Core Fund, Institutional 3 Class	10.0%
Columbia Quality Income Fund, Institutional 3 Class	8.9%
Columbia Large Cap Index Fund, Institutional 3 Class	8.0%
Columbia High Yield Bond Fund, Institutional 3 Class	6.0%
Columbia Diversified Fixed Income Allocation ETF	6.0%
Columbia Research Enhanced Core ETF	4.0%

Asset Categories

Largest Holdings [Text Block]

Top Holdings

Columbia Total Return Bond Fund, Institutional 3 Class	15.0%
Columbia Corporate Income Fund, Institutional 3 Class	12.0%
Columbia U.S. Treasury Index Fund, Institutional 3 Class	12.0%
Columbia Large Cap Enhanced Core Fund, Institutional 3 Class	10.1%
Columbia Contrarian Core Fund, Institutional 3 Class	10.0%
Columbia Quality Income Fund, Institutional 3 Class	8.9%
Columbia Large Cap Index Fund, Institutional 3 Class	8.0%
Columbia High Yield Bond Fund, Institutional 3 Class	6.0%
Columbia Diversified Fixed Income Allocation ETF	6.0%
Columbia Research Enhanced Core ETF	4.0%

Columbia Thermostat FundSM Advisor Class

Shareholder Report [Line Items]

Fund Name

Columbia Thermostat FundSM

Class Name

Advisor Class

Trading Symbol

CTORX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Thermostat FundSM (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

semi-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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Advisor Class	$13	0.25%

Expenses Paid, Amount

$ 13

Expense Ratio, Percent

0.25%

Net Assets

$ 1,250,944,133

Holdings Count | Holding

13

Investment Company, Portfolio Turnover

62.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$1,250,944,133
Total number of portfolio holdings	13
Portfolio turnover for the reporting period	62%

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.

Top Holdings

Columbia Total Return Bond Fund, Institutional 3 Class	15.0%
Columbia Corporate Income Fund, Institutional 3 Class	12.0%
Columbia U.S. Treasury Index Fund, Institutional 3 Class	12.0%
Columbia Large Cap Enhanced Core Fund, Institutional 3 Class	10.1%
Columbia Contrarian Core Fund, Institutional 3 Class	10.0%
Columbia Quality Income Fund, Institutional 3 Class	8.9%
Columbia Large Cap Index Fund, Institutional 3 Class	8.0%
Columbia High Yield Bond Fund, Institutional 3 Class	6.0%
Columbia Diversified Fixed Income Allocation ETF	6.0%
Columbia Research Enhanced Core ETF	4.0%

Asset Categories

Largest Holdings [Text Block]

Top Holdings

Columbia Total Return Bond Fund, Institutional 3 Class	15.0%
Columbia Corporate Income Fund, Institutional 3 Class	12.0%
Columbia U.S. Treasury Index Fund, Institutional 3 Class	12.0%
Columbia Large Cap Enhanced Core Fund, Institutional 3 Class	10.1%
Columbia Contrarian Core Fund, Institutional 3 Class	10.0%
Columbia Quality Income Fund, Institutional 3 Class	8.9%
Columbia Large Cap Index Fund, Institutional 3 Class	8.0%
Columbia High Yield Bond Fund, Institutional 3 Class	6.0%
Columbia Diversified Fixed Income Allocation ETF	6.0%
Columbia Research Enhanced Core ETF	4.0%

Columbia Thermostat FundSM Class C

Shareholder Report [Line Items]

Fund Name

Columbia Thermostat FundSM

Class Name

Class C

Trading Symbol

CTFDX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Thermostat FundSM (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

semi-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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Class C	$63	1.25%

Expenses Paid, Amount

$ 63

Expense Ratio, Percent

1.25%

Net Assets

$ 1,250,944,133

Holdings Count | Holding

13

Investment Company, Portfolio Turnover

62.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$1,250,944,133
Total number of portfolio holdings	13
Portfolio turnover for the reporting period	62%

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.

Top Holdings

Columbia Total Return Bond Fund, Institutional 3 Class	15.0%
Columbia Corporate Income Fund, Institutional 3 Class	12.0%
Columbia U.S. Treasury Index Fund, Institutional 3 Class	12.0%
Columbia Large Cap Enhanced Core Fund, Institutional 3 Class	10.1%
Columbia Contrarian Core Fund, Institutional 3 Class	10.0%
Columbia Quality Income Fund, Institutional 3 Class	8.9%
Columbia Large Cap Index Fund, Institutional 3 Class	8.0%
Columbia High Yield Bond Fund, Institutional 3 Class	6.0%
Columbia Diversified Fixed Income Allocation ETF	6.0%
Columbia Research Enhanced Core ETF	4.0%

Asset Categories

Largest Holdings [Text Block]

Top Holdings

Columbia Total Return Bond Fund, Institutional 3 Class	15.0%
Columbia Corporate Income Fund, Institutional 3 Class	12.0%
Columbia U.S. Treasury Index Fund, Institutional 3 Class	12.0%
Columbia Large Cap Enhanced Core Fund, Institutional 3 Class	10.1%
Columbia Contrarian Core Fund, Institutional 3 Class	10.0%
Columbia Quality Income Fund, Institutional 3 Class	8.9%
Columbia Large Cap Index Fund, Institutional 3 Class	8.0%
Columbia High Yield Bond Fund, Institutional 3 Class	6.0%
Columbia Diversified Fixed Income Allocation ETF	6.0%
Columbia Research Enhanced Core ETF	4.0%

Columbia Thermostat FundSM Institutional Class

Shareholder Report [Line Items]

Fund Name

Columbia Thermostat FundSM

Class Name

Institutional Class

Trading Symbol

COTZX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Thermostat FundSM (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

semi-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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Institutional Class	$13	0.25%

Expenses Paid, Amount

$ 13

Expense Ratio, Percent

0.25%

Net Assets

$ 1,250,944,133

Holdings Count | Holding

13

Investment Company, Portfolio Turnover

62.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$1,250,944,133
Total number of portfolio holdings	13
Portfolio turnover for the reporting period	62%

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.

Top Holdings

Columbia Total Return Bond Fund, Institutional 3 Class	15.0%
Columbia Corporate Income Fund, Institutional 3 Class	12.0%
Columbia U.S. Treasury Index Fund, Institutional 3 Class	12.0%
Columbia Large Cap Enhanced Core Fund, Institutional 3 Class	10.1%
Columbia Contrarian Core Fund, Institutional 3 Class	10.0%
Columbia Quality Income Fund, Institutional 3 Class	8.9%
Columbia Large Cap Index Fund, Institutional 3 Class	8.0%
Columbia High Yield Bond Fund, Institutional 3 Class	6.0%
Columbia Diversified Fixed Income Allocation ETF	6.0%
Columbia Research Enhanced Core ETF	4.0%

Asset Categories

Largest Holdings [Text Block]

Top Holdings

Columbia Total Return Bond Fund, Institutional 3 Class	15.0%
Columbia Corporate Income Fund, Institutional 3 Class	12.0%
Columbia U.S. Treasury Index Fund, Institutional 3 Class	12.0%
Columbia Large Cap Enhanced Core Fund, Institutional 3 Class	10.1%
Columbia Contrarian Core Fund, Institutional 3 Class	10.0%
Columbia Quality Income Fund, Institutional 3 Class	8.9%
Columbia Large Cap Index Fund, Institutional 3 Class	8.0%
Columbia High Yield Bond Fund, Institutional 3 Class	6.0%
Columbia Diversified Fixed Income Allocation ETF	6.0%
Columbia Research Enhanced Core ETF	4.0%

Columbia Thermostat FundSM Institutional 2 Class

Shareholder Report [Line Items]

Fund Name

Columbia Thermostat FundSM

Class Name

Institutional 2 Class

Trading Symbol

CQTRX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Thermostat FundSM (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

semi-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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Institutional 2 Class	$10	0.20%

Expenses Paid, Amount

$ 10

Expense Ratio, Percent

0.20%

Net Assets

$ 1,250,944,133

Holdings Count | Holding

13

Investment Company, Portfolio Turnover

62.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$1,250,944,133
Total number of portfolio holdings	13
Portfolio turnover for the reporting period	62%

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.

Top Holdings

Columbia Total Return Bond Fund, Institutional 3 Class	15.0%
Columbia Corporate Income Fund, Institutional 3 Class	12.0%
Columbia U.S. Treasury Index Fund, Institutional 3 Class	12.0%
Columbia Large Cap Enhanced Core Fund, Institutional 3 Class	10.1%
Columbia Contrarian Core Fund, Institutional 3 Class	10.0%
Columbia Quality Income Fund, Institutional 3 Class	8.9%
Columbia Large Cap Index Fund, Institutional 3 Class	8.0%
Columbia High Yield Bond Fund, Institutional 3 Class	6.0%
Columbia Diversified Fixed Income Allocation ETF	6.0%
Columbia Research Enhanced Core ETF	4.0%

Asset Categories

Largest Holdings [Text Block]

Top Holdings

Columbia Total Return Bond Fund, Institutional 3 Class	15.0%
Columbia Corporate Income Fund, Institutional 3 Class	12.0%
Columbia U.S. Treasury Index Fund, Institutional 3 Class	12.0%
Columbia Large Cap Enhanced Core Fund, Institutional 3 Class	10.1%
Columbia Contrarian Core Fund, Institutional 3 Class	10.0%
Columbia Quality Income Fund, Institutional 3 Class	8.9%
Columbia Large Cap Index Fund, Institutional 3 Class	8.0%
Columbia High Yield Bond Fund, Institutional 3 Class	6.0%
Columbia Diversified Fixed Income Allocation ETF	6.0%
Columbia Research Enhanced Core ETF	4.0%

Columbia Thermostat FundSM Institutional 3 Class

Shareholder Report [Line Items]

Fund Name

Columbia Thermostat FundSM

Class Name

Institutional 3 Class

Trading Symbol

CYYYX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Thermostat FundSM (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

semi-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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Institutional 3 Class	$8	0.16%

Expenses Paid, Amount

$ 8

Expense Ratio, Percent

0.16%

Net Assets

$ 1,250,944,133

Holdings Count | Holding

13

Investment Company, Portfolio Turnover

62.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$1,250,944,133
Total number of portfolio holdings	13
Portfolio turnover for the reporting period	62%

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.

Top Holdings

Columbia Total Return Bond Fund, Institutional 3 Class	15.0%
Columbia Corporate Income Fund, Institutional 3 Class	12.0%
Columbia U.S. Treasury Index Fund, Institutional 3 Class	12.0%
Columbia Large Cap Enhanced Core Fund, Institutional 3 Class	10.1%
Columbia Contrarian Core Fund, Institutional 3 Class	10.0%
Columbia Quality Income Fund, Institutional 3 Class	8.9%
Columbia Large Cap Index Fund, Institutional 3 Class	8.0%
Columbia High Yield Bond Fund, Institutional 3 Class	6.0%
Columbia Diversified Fixed Income Allocation ETF	6.0%
Columbia Research Enhanced Core ETF	4.0%

Asset Categories

Largest Holdings [Text Block]

Top Holdings

Columbia Total Return Bond Fund, Institutional 3 Class	15.0%
Columbia Corporate Income Fund, Institutional 3 Class	12.0%
Columbia U.S. Treasury Index Fund, Institutional 3 Class	12.0%
Columbia Large Cap Enhanced Core Fund, Institutional 3 Class	10.1%
Columbia Contrarian Core Fund, Institutional 3 Class	10.0%
Columbia Quality Income Fund, Institutional 3 Class	8.9%
Columbia Large Cap Index Fund, Institutional 3 Class	8.0%
Columbia High Yield Bond Fund, Institutional 3 Class	6.0%
Columbia Diversified Fixed Income Allocation ETF	6.0%
Columbia Research Enhanced Core ETF	4.0%

Columbia Acorn European FundSM Class A

Shareholder Report [Line Items]

Fund Name

Columbia Acorn European FundSM

Class Name

Class A

Trading Symbol

CAEAX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn European FundSM (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

semi-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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Class A	$72	1.45%

Expenses Paid, Amount

$ 72

Expense Ratio, Percent

1.45%

Net Assets

$ 49,473,773

Holdings Count | Holding

52

Investment Company, Portfolio Turnover

20.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$49,473,773
Total number of portfolio holdings	52
Portfolio turnover for the reporting period	20%

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.

Top Holdings

AddTech AB, B Shares	4.2%
Diploma PLC	4.2%
Amplifon SpA	4.1%
Intermediate Capital Group PLC	4.0%
Auto Trader Group PLC	4.0%
Rightmove PLC	4.0%
Belimo Holding AG, Registered Shares	3.9%
Munters Group AB	3.6%
Carel Industries SpA	3.3%
Hexagon AB, Class B	3.2%

Equity Sector Allocation

Geographic Allocation

Largest Holdings [Text Block]

Top Holdings

AddTech AB, B Shares	4.2%
Diploma PLC	4.2%
Amplifon SpA	4.1%
Intermediate Capital Group PLC	4.0%
Auto Trader Group PLC	4.0%
Rightmove PLC	4.0%
Belimo Holding AG, Registered Shares	3.9%
Munters Group AB	3.6%
Carel Industries SpA	3.3%
Hexagon AB, Class B	3.2%

Columbia Acorn European FundSM Advisor Class

Shareholder Report [Line Items]

Fund Name

Columbia Acorn European FundSM

Class Name

Advisor Class

Trading Symbol

CLOFX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn European FundSM (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

semi-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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Advisor Class	$59	1.20%

Expenses Paid, Amount

$ 59

Expense Ratio, Percent

1.20%

Net Assets

$ 49,473,773

Holdings Count | Holding

52

Investment Company, Portfolio Turnover

20.00%

Additional Fund Statistics [Text Block]

Key Fund Statistics

Fund net assets	$49,473,773
Total number of portfolio holdings	52
Portfolio turnover for the reporting period	20%

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.

Top Holdings

AddTech AB, B Shares	4.2%
Diploma PLC	4.2%
Amplifon SpA	4.1%
Intermediate Capital Group PLC	4.0%
Auto Trader Group PLC	4.0%
Rightmove PLC	4.0%
Belimo Holding AG, Registered Shares	3.9%
Munters Group AB	3.6%
Carel Industries SpA	3.3%
Hexagon AB, Class B	3.2%

Equity Sector Allocation

Geographic Allocation

Largest Holdings [Text Block]

Top Holdings

AddTech AB, B Shares	4.2%
Diploma PLC	4.2%
Amplifon SpA	4.1%
Intermediate Capital Group PLC	4.0%
Auto Trader Group PLC	4.0%
Rightmove PLC	4.0%
Belimo Holding AG, Registered Shares	3.9%
Munters Group AB	3.6%
Carel Industries SpA	3.3%
Hexagon AB, Class B	3.2%

Columbia Acorn European FundSM Institutional Class

Shareholder Report [Line Items]

Fund Name

Columbia Acorn European FundSM

Class Name

Institutional Class

Trading Symbol

CAEZX

Annual or Semi-Annual Statement [Text Block]

This semiannual shareholder report contains important information about Columbia Acorn European FundSM (the Fund) for the period of January 1, 2024 to June 30, 2024.

Shareholder Report Annual or Semi-Annual

semi-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	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Institutional Class	$59	1.20%

Expenses Paid, Amount

$ 59

Expense Ratio, Percent

1.20%

Net Assets

$ 49,473,773

Holdings Count | Holding

52

Investment Company, Portfolio Turnover

20.00%

Additional Fund Statistics [Text Block]

Fund net assets	$49,473,773
Total number of portfolio holdings	52
Portfolio turnover for the reporting period	20%

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.

Top Holdings

AddTech AB, B Shares	4.2%
Diploma PLC	4.2%
Amplifon SpA	4.1%
Intermediate Capital Group PLC	4.0%
Auto Trader Group PLC	4.0%
Rightmove PLC	4.0%
Belimo Holding AG, Registered Shares	3.9%
Munters Group AB	3.6%
Carel Industries SpA	3.3%
Hexagon AB, Class B	3.2%

Equity Sector Allocation

Geographic Allocation

Largest Holdings [Text Block]

Top Holdings

AddTech AB, B Shares	4.2%
Diploma PLC	4.2%
Amplifon SpA	4.1%
Intermediate Capital Group PLC	4.0%
Auto Trader Group PLC	4.0%
Rightmove PLC	4.0%
Belimo Holding AG, Registered Shares	3.9%
Munters Group AB	3.6%
Carel Industries SpA	3.3%
Hexagon AB, Class B	3.2%