XML 44 R2.htm IDEA: XBRL DOCUMENT v3.24.3
Shareholder Report
 12 Months Ended
Aug. 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 Aug. 31, 2024
Columbia Small Cap Growth Fund - Class A  
Shareholder Report [Line Items]  
Fund Name Columbia Small Cap Growth Fund
Class Name Class A
Trading Symbol CGOAX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Columbia Small Cap Growth Fund (the Fund) for the period of September 1, 2023 to August 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)
ClassCost of a $10,000 investmentCost paid as a percentage of a $10,000 investment
Class A
$
136		1.25
%
Expenses Paid, Amount $ 136
Expense Ratio, Percent 1.25%
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
Stock selection
| Selections in the industrials and materials sectors boosted the Fund’s relative results most during the annual period.
Allocations
| Underweight positioning in the utilities sector buoyed relative Fund results during the annual period.
Individual holdings
| Positions in FTAI Aviation, an aerospace manufacturer; CAVA Group, a restaurant holding company; and Natera, a medical diagnostics company, were among the top contributors to relative Fund performance.
Top Performance Detractors
Stock selection
| Selections in the information technology and financials sectors hurt the Fund’s relative results during the annual period.
Allocations
| Underweight positions in the financials sector detracted from relative performance.
Individual holdings
| Fund positions in MicroStrategy, a technology company; BILL Holdings, a payments company; and Aehr Test Systems, a semiconductor equipment company, were top detractors during the period.
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 year5 years10 years
Class A (excluding sales charges)
(a)
18.3110.0112.57
Class A (including sales charges)
(a)
11.528.7211.91
Russell
®
2000 Growth Index		17.678.358.21
Russell
®
3000 Index		26.1415.1912.36
(a)
Effective August 1, 2024, the Fund compares its performance to the Russell
®
3000 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.
Updated Performance Information Location [Text Block] Visit
columbiathreadneedleus.com/investment-products/mutual-funds
for more recent performance information.
Net Assets $ 2,096,141,883
Holdings Count | Holding 101
Advisory Fees Paid, Amount $ 14,710,617
Investment Company, Portfolio Turnover 146.00%
Additional Fund Statistics [Text Block]
Key Fund Statistics
Fund net assets
$
2,096,141,883
Tot
al number of
portfolio holdings		101
Management services fees
(represents 0.81% of Fund average net assets)
$
14,710,617
Portfolio turnover for the reporting period 146%
Holdings [Text Block]
Graphical Representation of Fund
 
Holdings
The tables below show the investment makeup of the Fund repr
esen
ted 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 Holdi
ngs
FTAI Aviation Ltd.3.1
%
Carpenter Technology Corp.2.9
%
Onto Innovation, Inc.2.8
%
AAON, Inc.2.7
%
XPO, Inc.2.7
%
SiteOne Landscape Supply, Inc.2.5
%
Chemed Corp.2.5
%
ICU Medical, Inc.2.5
%
RBC Bearings, Inc.2.3
%
Bio-Techne Corp.2.3
%
Asset Categories

Equity Sector Allocation
Largest Holdings [Text Block]
Top Holdi
ngs
FTAI Aviation Ltd.3.1
%
Carpenter Technology Corp.2.9
%
Onto Innovation, Inc.2.8
%
AAON, Inc.2.7
%
XPO, Inc.2.7
%
SiteOne Landscape Supply, Inc.2.5
%
Chemed Corp.2.5
%
ICU Medical, Inc.2.5
%
RBC Bearings, Inc.2.3
%
Bio-Techne Corp.2.3
%
Updated Prospectus Web Address columbiathreadneedleus.com/investment-products/mutual-funds
Columbia Small Cap Growth Fund - Advisor Class  
Shareholder Report [Line Items]  
Fund Name Columbia Small Cap Growth Fund
Class Name Advisor Class
Trading Symbol CHHRX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Columbia Small Cap Growth Fund (the Fund) for the period of September 1, 2023 to August 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)
ClassCost of a $10,000 investmentCost paid as a percentage of a $10,000 investment
Advisor Class
$
108		0.99
%
Expenses Paid, Amount $ 108
Expense Ratio, Percent 0.99%
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
Stock selection
| Selections in the industrials and materials sectors boosted the Fund’s relative results most during the annual period.
Allocations
| Underweight positioning in the utilities sector buoyed relative Fund results during the annual period.
Individual holdings
| Positions in FTAI Aviation, an aerospace manufacturer; CAVA Group, a restaurant holding company; and Natera, a medical diagnostics company, were among the top contributors to relative Fund performance.
Top Performance Detractors
Stock selection
| Selections in the information technology and financials sectors hurt the Fund’s relative results during the annual period.
Allocations
| Underweight positions in the financials sector detracted from relative performance.
Individual holdings
| Fund positions in MicroStrategy, a technology company; BILL Holdings, a payments company; and Aehr Test Systems, a semiconductor equipment company, were top detractors during the period.
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 year5 years10 years
Advisor Class
(a)
18.6610.2912.86
Russell
®
2000 Growth Index		17.678.358.21
Russell
®
3000 Index		26.1415.1912.36
(a)
Effective August 1, 2024, the Fund compares its performance to the Russell
®
3000 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.
Updated Performance Information Location [Text Block] Visit
columbiathreadneedleus.com/investment-products/mutual-funds
for more recent performance information.
Net Assets $ 2,096,141,883
Holdings Count | Holding 101
Advisory Fees Paid, Amount $ 14,710,617
Investment Company, Portfolio Turnover 146.00%
Additional Fund Statistics [Text Block]
Key Fund Statistics
Fund net assets
$
2,096,141,883
Total number of portfo
lio holdin
gs		101
Management services fees
(represents 0.81% of Fund average net assets)
$
14,710,617
Portfolio turnover for the reporting period 146%
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 portfo
lio
composition is subject to change.
Top Holdings
FTAI Aviation Ltd.3.1
%
Carpenter Technology Corp.2.9
%
Onto Innovation, Inc.2.8
%
AAON, Inc.2.7
%
XPO, Inc.2.7
%
SiteOne Landscape Supply, Inc.2.5
%
Chemed Corp.2.5
%
ICU Medical, Inc.2.5
%
RBC Bearings, Inc.2.3
%
Bio-Techne Corp.2.3
%
Asset Categories

Equity Sector Allocation
Largest Holdings [Text Block]
Top Holdings
FTAI Aviation Ltd.3.1
%
Carpenter Technology Corp.2.9
%
Onto Innovation, Inc.2.8
%
AAON, Inc.2.7
%
XPO, Inc.2.7
%
SiteOne Landscape Supply, Inc.2.5
%
Chemed Corp.2.5
%
ICU Medical, Inc.2.5
%
RBC Bearings, Inc.2.3
%
Bio-Techne Corp.2.3
%
Updated Prospectus Web Address columbiathreadneedleus.com/investment-products/mutual-funds
Columbia Small Cap Growth Fund - Class C  
Shareholder Report [Line Items]  
Fund Name Columbia Small Cap Growth Fund
Class Name Class C
Trading Symbol CGOCX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Columbia Small Cap Growth Fund (the Fund) for the period of September 1, 2023 to August 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)
ClassCost of a $10,000 investmentCost paid as a percentage of a $10,000 investment
Class C
$
217		2.00
%
Expenses Paid, Amount $ 217
Expense Ratio, Percent 2.00%
Factors Affecting Performance [Text Block]
Management's Discussion of Fund Performance
The performance of Class C shares for the period presented is shown in the Average Annual Total Returns table.
Top Performance Contributors
Stock selection
| Selections in the industrials and materials sectors boosted the Fund’s relative results most during the annual period.
Allocations
| Underweight positioning in the utilities sector buoyed relative Fund results during the annual period.
Individual holdings
| Positions in FTAI Aviation, an aerospace manufacturer; CAVA Group, a restaurant holding company; and Natera, a medical diagnostics company, were among the top contributors to relative Fund performance.
Top Performance Detractors
Stock selection
| Selections in the information technology and financials sectors hurt the Fund’s relative results during the annual period.
Allocations
| Underweight positions in the financials sector detracted from relative performance.
Individual holdings
| Fund positions in MicroStrategy, a technology company; BILL Holdings, a payments company; and Aehr Test Systems, a semiconductor equipment company, were top detractors during the period.
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 year5 years10 years
Class C (excluding sales charges)
(a)
17.489.2011.73
Class C (including sales charges)
(a)
16.489.2011.73
Russell
®
2000 Growth Index		17.678.358.21
Russell
®
3000 Index		26.1415.1912.36
(a)
Effective August 1, 2024, the Fund compares its performance to the Russell
®
3000 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.
Updated Performance Information Location [Text Block] Visit
columbiathreadneedleus.com/investment-products/mutual-funds
for more recent performance information.
Net Assets $ 2,096,141,883
Holdings Count | Holding 101
Advisory Fees Paid, Amount $ 14,710,617
Investment Company, Portfolio Turnover 146.00%
Additional Fund Statistics [Text Block]
Key Fund Sta
tist
ics
Fund net
assets
$
2,096,141,883
Total number of portfolio holdings101
Management services fees
(represents 0.81% of Fund average net assets)
$
14,710,617
Portfolio turnover for the reporting period 146%
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 H
oldings
FTAI Aviation Ltd.3.1
%
Carpenter Technology Corp.2.9
%
Onto Innovation, Inc.2.8
%
AAON, Inc.2.7
%
XPO, Inc.2.7
%
SiteOne Landscape Supply, Inc.2.5
%
Chemed Corp.2.5
%
ICU Medical, Inc.2.5
%
RBC Bearings, Inc.2.3
%
Bio-Techne Corp.2.3
%
Asset Categories

Equity Sector Allocation
Largest Holdings [Text Block]
Top H
oldings
FTAI Aviation Ltd.3.1
%
Carpenter Technology Corp.2.9
%
Onto Innovation, Inc.2.8
%
AAON, Inc.2.7
%
XPO, Inc.2.7
%
SiteOne Landscape Supply, Inc.2.5
%
Chemed Corp.2.5
%
ICU Medical, Inc.2.5
%
RBC Bearings, Inc.2.3
%
Bio-Techne Corp.2.3
%
Updated Prospectus Web Address columbiathreadneedleus.com/investment-products/mutual-funds
Columbia Small Cap Growth Fund - Institutional Class  
Shareholder Report [Line Items]  
Fund Name Columbia Small Cap Growth Fund
Class Name Institutional Class
Trading Symbol CMSCX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Columbia Small Cap Growth Fund (the Fund) for the period of September 1, 2023 to August 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)
ClassCost of a $10,000 investmentCost paid as a percentage of a $10,000 investment
Institutional Class
$
108		0.99
%
Expenses Paid, Amount $ 108
Expense Ratio, Percent 0.99%
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
Stock selection
| Selections in the industrials and materials sectors boosted the Fund’s relative results most during the annual period.
Allocations
| Underweight positioning in the utilities sector buoyed relative Fund results during the annual period.
Individual holdings
| Positions in FTAI Aviation, an aerospace manufacturer; CAVA Group, a restaurant holding company; and Natera, a medical diagnostics company, were among the top contributors to relative Fund performance.
Top Performance Detractors
Stock selection
| Selections in the information technology and financials sectors hurt the Fund’s relative results during the annual period.
Allocations
| Underweight positions in the financials sector detracted from relative performance.
Individual holdings
| Fund positions in MicroStrategy, a technology company; BILL Holdings, a payments company; and Aehr Test Systems, a semiconductor equipment company, were top detractors during the period.
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 year5 years10 years
Institutional Class
(a)
18.6610.2812.86
Russell
®
2000 Growth Index		17.678.358.21
Russell
®
3000 Index		26.1415.1912.36
(a)
Effective August 1, 2024, the Fund compares its performance to the Russell
®
3000 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.
Updated Performance Information Location [Text Block] Visit
columbiathreadneedleus.com/investment-products/mutual-funds
for more recent performance information.
Net Assets $ 2,096,141,883
Holdings Count | Holding 101
Advisory Fees Paid, Amount $ 14,710,617
Investment Company, Portfolio Turnover 146.00%
Additional Fund Statistics [Text Block]
Key Fund Statistics
Fund net
assets
$
2,096,141,883
Total number of portfolio holdings101
Managemen
t serv
ices fees
(represents 0.81% of Fund average net assets)
$
14,710,617
Portfolio turnover for the reporting period 146%
Holdings [Text Block]
Graphical Repr
esenta
tion 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
FTAI Aviation Ltd.3.1
%
Carpenter Technology Corp.2.9
%
Onto Innovation,
Inc
.		2.8
%
AAON, Inc.2.7
%
XPO, Inc.2.7
%
SiteOne Landscape Supply, Inc.2.5
%
Chemed Corp.2.5
%
ICU Medical, Inc.2.5
%
RBC Bearings, Inc.2.3
%
Bio-Techne Corp.2.3
%
Asset Categories

Equity Sector Allocation
Largest Holdings [Text Block]
Top Holdings
FTAI Aviation Ltd.3.1
%
Carpenter Technology Corp.2.9
%
Onto Innovation,
Inc
.		2.8
%
AAON, Inc.2.7
%
XPO, Inc.2.7
%
SiteOne Landscape Supply, Inc.2.5
%
Chemed Corp.2.5
%
ICU Medical, Inc.2.5
%
RBC Bearings, Inc.2.3
%
Bio-Techne Corp.2.3
%
Updated Prospectus Web Address columbiathreadneedleus.com/investment-products/mutual-funds
Columbia Small Cap Growth Fund - Institutional 2 Class  
Shareholder Report [Line Items]  
Fund Name Columbia Small Cap Growth Fund
Class Name Institutional 2 Class
Trading Symbol CSCRX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Columbia Small Cap Growth Fund (the Fund) for the period of September 1, 2023 to August 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)
ClassCost of a $10,000 investmentCost paid as a percentage of a $10,000 investment
Institutional 2 Class
$
97		0.89
%
Expenses Paid, Amount $ 97
Expense Ratio, Percent 0.89%
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
Stock selection
| Selections in the industrials and materials sectors boosted the Fund’s relative results most during the annual period.
Allocations
| Underweight positioning in the utilities sector buoyed relative Fund results during the annual period.
Individual holdings
| Positions in FTAI Aviation, an aerospace manufacturer; CAVA Group, a restaurant holding company; and Natera, a medical diagnostics company, were among the top contributors to relative Fund performance.
Top Performance Detractors
Stock selection
| Selections in the information technology and financials sectors hurt the Fund’s relative results during the annual period.
Allocations
| Underweight positions in the financials sector detracted from relative performance.
Individual holdings
| Fund positions in MicroStrategy, a technology company; BILL Holdings, a payments company; and Aehr Test Systems, a semiconductor equipment company, were top detractors during the period.
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 year5 years10 years
Institutional 2 Class
(a)
18.7910.4012.98
Russell
®
2000 Growth Index		17.678.358.21
Russell
®
3000 Index		26.1415.1912.36
(a)
Effective August 1, 2024, the Fund compares its performance to the Russell
®
3000 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.
Updated Performance Information Location [Text Block] Visit
columbiathreadneedleus.com/investment-products/mutual-funds
for more recent performance information.
Net Assets $ 2,096,141,883
Holdings Count | Holding 101
Advisory Fees Paid, Amount $ 14,710,617
Investment Company, Portfolio Turnover 146.00%
Additional Fund Statistics [Text Block]
Key Fund Statistics
Fund net assets
$
2,096,141,883
Total number of portfolio holdings101
Management services fees
(represents 0.81% of Fund average net assets)
$
14,710,617
Portfolio turnover for th
e rep
orting period 		146%
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
FTAI Aviation
Ltd
.		3.1
%
Carpenter Technology Corp.2.9
%
Onto Innovation, Inc.2.8
%
AAON, Inc.2.7
%
XPO, Inc.2.7
%
SiteOne Landscape Supply, Inc.2.5
%
Chemed Corp.2.5
%
ICU Medical, Inc.2.5
%
RBC Bearings, Inc.2.3
%
Bio-Techne Corp.2.3
%
Asset Categories

Equity Sector Allocation
Largest Holdings [Text Block]
Top Holdings
FTAI Aviation
Ltd
.		3.1
%
Carpenter Technology Corp.2.9
%
Onto Innovation, Inc.2.8
%
AAON, Inc.2.7
%
XPO, Inc.2.7
%
SiteOne Landscape Supply, Inc.2.5
%
Chemed Corp.2.5
%
ICU Medical, Inc.2.5
%
RBC Bearings, Inc.2.3
%
Bio-Techne Corp.2.3
%
Updated Prospectus Web Address columbiathreadneedleus.com/investment-products/mutual-funds
Columbia Small Cap Growth Fund - Institutional 3 Class  
Shareholder Report [Line Items]  
Fund Name Columbia Small Cap Growth Fund
Class Name Institutional 3 Class
Trading Symbol CSGYX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Columbia Small Cap Growth Fund (the Fund) for the period of September 1, 2023 to August 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)
ClassCost of a $10,000 investmentCost paid as a percentage of a $10,000 investment
Institutional 3 Class
$
92		0.84
%
Expenses Paid, Amount $ 92
Expense Ratio, Percent 0.84%
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
Stock selection
| Selections in the industrials and materials sectors boosted the Fund’s relative results most during the annual period.
Allocations
| Underweight positioning in the utilities sector buoyed relative Fund results during the annual period.
Individual holdings
| Positions in FTAI Aviation, an aerospace manufacturer; CAVA Group, a restaurant holding company; and Natera, a medical diagnostics company, were among the top contributors to relative Fund performance.
Top Performance Detractors
Stock selection
| Selections in the information technology and financials sectors hurt the Fund’s relative results during the annual period.
Allocations
| Underweight positions in the financials sector detracted from relative performance.
Individual holdings
| Fund positions in MicroStrategy, a technology company; BILL Holdings, a payments company; and Aehr Test Systems, a semiconductor equipment company, were top detractors during the period.
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 year5 years10 years
Institutional 3 Class
(a)
18.7610.4413.03
Russell
®
2000 Growth Index		17.678.358.21
Russell
®
3000 Index		26.1415.1912.36
(a)
Effective August 1, 2024, the Fund compares its performance to the Russell
®
3000 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.
Updated Performance Information Location [Text Block] Visit
columbiathreadneedleus.com/investment-products/mutual-funds
for more recent performance information.
Net Assets $ 2,096,141,883
Holdings Count | Holding 101
Advisory Fees Paid, Amount $ 14,710,617
Investment Company, Portfolio Turnover 146.00%
Additional Fund Statistics [Text Block]
Key Fund Statistics
Fund net assets
$
2,096,141,883
Total number of portfolio holdings101
Managem
ent ser
vices fees
(represents 0.81% of Fund average net assets)
$
14,710,617
Portfolio turnover for the reporting period 146%
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
FTAI Aviation Ltd.3.1
%
Carpenter Technology Corp.2.9
%
Onto Innovation, Inc.2.8
%
AAON, Inc.2.7
%
XPO, Inc.2.7
%
SiteOne Landscape Supply, Inc.2.5
%
Chemed Corp.2.5
%
ICU M
edica
l, Inc.		2.5
%
RBC Bearings, Inc.2.3
%
Bio-Techne Corp.2.3
%
Asset Categories

Equity Sector Allocation
Largest Holdings [Text Block]
Top Holdings
FTAI Aviation Ltd.3.1
%
Carpenter Technology Corp.2.9
%
Onto Innovation, Inc.2.8
%
AAON, Inc.2.7
%
XPO, Inc.2.7
%
SiteOne Landscape Supply, Inc.2.5
%
Chemed Corp.2.5
%
ICU M
edica
l, Inc.		2.5
%
RBC Bearings, Inc.2.3
%
Bio-Techne Corp.2.3
%
Updated Prospectus Web Address columbiathreadneedleus.com/investment-products/mutual-funds
Columbia Small Cap Growth Fund - Class R  
Shareholder Report [Line Items]  
Fund Name Columbia Small Cap Growth Fund
Class Name Class R
Trading Symbol CCRIX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Columbia Small Cap Growth Fund (the Fund) for the period of September 1, 2023 to August 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)
ClassCost of a $10,000 investmentCost paid as a percentage of a $10,000 investment
Class R
$
163		1.50
%
Expenses Paid, Amount $ 163
Expense Ratio, Percent 1.50%
Factors Affecting Performance [Text Block]
Management's Discussion of Fund Performance
The performance of Class R shares for the period presented is shown in the Average Annual Total Returns table.
Top Performance Contributors
Stock selection
| Selections in the industrials and materials sectors boosted the Fund’s relative results most during the annual period.
Allocations
| Underweight positioning in the utilities sector buoyed relative Fund results during the annual period.
Individual holdings
| Positions in FTAI Aviation, an aerospace manufacturer; CAVA Group, a restaurant holding company; and Natera, a medical diagnostics company, were among the top contributors to relative Fund performance.
Top Performance Detractors
Stock selection
| Selections in the information technology and financials sectors hurt the Fund’s relative results during the annual period.
Allocations
| Underweight positions in the financials sector detracted from relative performance.
Individual holdings
| Fund positions in MicroStrategy, a technology company; BILL Holdings, a payments company; and Aehr Test Systems, a semiconductor equipment company, were top detractors during the period.
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 year5 years10 years
Class R
(a)
18.009.7312.29
Russell
®
2000 Growth Index		17.678.358.21
Russell
®
3000 Index		26.1415.1912.36
(a)
Effective August 1, 2024, the Fund compares its performance to the Russell
®
3000 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.
Updated Performance Information Location [Text Block] Visit
columbiathreadneedleus.com/investment-products/mutual-funds
for more recent performance information.
Net Assets $ 2,096,141,883
Holdings Count | Holding 101
Advisory Fees Paid, Amount $ 14,710,617
Investment Company, Portfolio Turnover 146.00%
Additional Fund Statistics [Text Block]
Key Fund Statistics
Fun
d net asset
s
$
2,096,141,883
Total number of portfolio holdings101
Management services fees
(represents 0.81% of Fund average net assets)
$
14,710,617
Portfolio turnover for the reporting period 146%
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
FTAI Aviation Ltd.3.1
%
Carpenter Technology Corp.2.9
%
Onto Innovation, Inc.2.8
%
AAON, Inc.2.7
%
XPO, Inc.2.7
%
SiteOne Landscape Supply, Inc.2.5
%
Chemed Corp.2.5
%
ICU Medical, Inc.2.5
%
RBC Bearings, Inc.2.3
%
Bio-Techne Corp.2.3
%
Asset Categories

Equity Sector Allocation
Largest Holdings [Text Block]
Top Holdings
FTAI Aviation Ltd.3.1
%
Carpenter Technology Corp.2.9
%
Onto Innovation, Inc.2.8
%
AAON, Inc.2.7
%
XPO, Inc.2.7
%
SiteOne Landscape Supply, Inc.2.5
%
Chemed Corp.2.5
%
ICU Medical, Inc.2.5
%
RBC Bearings, Inc.2.3
%
Bio-Techne Corp.2.3
%
Updated Prospectus Web Address columbiathreadneedleus.com/investment-products/mutual-funds