Investment Strategy	Mar. 31, 2026
S000036204 [Member]
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of large capitalization companies. These companies have market capitalizations in the range of companies in the Russell 1000® Growth Index (the Capitalization Index), which ranged between $776.8 million and $4.8 trillion as of June 30, 2026. The market capitalization range and composition of companies in the Capitalization Index are subject to change. As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index. Under normal circumstances, the Fund also invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of “growth” companies. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding the future earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years. The Fund invests substantially in securities of U.S. issuers. The Fund generally invests in common stocks. The Fund may at times emphasize one or more sectors in selecting its investments. As of its most recent fiscal year end, the Fund had an investment emphasis in the information technology sector. The Fund may also invest in exchange-traded funds (ETFs).
Summary of Definition of Rule 35d-1 Term in Fund Name [Text Block]	Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of large capitalization companies. These companies have market capitalizations in the range of companies in the Russell 1000® Growth Index (the Capitalization Index), which ranged between $776.8 million and $4.8 trillion as of June 30, 2026. The market capitalization range and composition of companies in the Capitalization Index are subject to change. As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index. Under normal circumstances, the Fund also invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of “growth” companies. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding the future earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years.
Summary of Selection Criteria for Rule 35d-1 Term in Fund Name [Text Block]	These companies have market capitalizations in the range of companies in the Russell 1000® Growth Index (the Capitalization Index), which ranged between $776.8 million and $4.8 trillion as of June 30, 2026.The market capitalization range and composition of companies in the Capitalization Index are subject to change.As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding the future earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years.
Rule 35d-1 Eighty Percent Investment Policy [Text Block]	Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of large capitalization companies.Under normal circumstances, the Fund also invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of “growth” companies.
S000021575 [Member]
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in common stocks of U.S. and foreign companies that have market capitalizations in the range of companies in the Russell 1000® Growth Index (the Capitalization Index). The market capitalization range of the companies included within the Capitalization Index was $776.8 million to $4.8 trillion as of June 30, 2026. The market capitalization range and composition of companies in the Capitalization Index are subject to change. As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index. The Fund invests primarily in common stocks of companies believed to have the potential for long-term growth. Under normal circumstances, the Fund also invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of “growth” companies. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding the future earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years. The Fund typically employs a focused portfolio investing style, which results in fewer holdings than a fund that seeks to achieve its investment objective by investing in a greater number of issuers. The Fund may invest directly in foreign securities or indirectly through depositary receipts. The Fund may at times emphasize one or more sectors in selecting its investments. As of its most recent fiscal year end, the Fund had an investment emphasis in the information technology sector.
Summary of Definition of Rule 35d-1 Term in Fund Name [Text Block]	Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in common stocks of U.S. and foreign companies that have market capitalizations in the range of companies in the Russell 1000® Growth Index (the Capitalization Index). The market capitalization range of the companies included within the Capitalization Index was $776.8 million to $4.8 trillion as of June 30, 2026. The market capitalization range and composition of companies in the Capitalization Index are subject to change. As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index. The Fund invests primarily in common stocks of companies believed to have the potential for long-term growth. Under normal circumstances, the Fund also invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of “growth” companies. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding the future earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years.
Summary of Selection Criteria for Rule 35d-1 Term in Fund Name [Text Block]	The market capitalization range of the companies included within the Capitalization Index was $776.8 million to $4.8 trillion as of June 30, 2026.The market capitalization range and composition of companies in the Capitalization Index are subject to change.As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index.The Fund invests primarily in common stocks of companies believed to have the potential for long-term growth. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding thefuture earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years.
Rule 35d-1 Eighty Percent Investment Policy [Text Block]	Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in common stocks of U.S. and foreign companies that have market capitalizationsin the range of companies in the Russell 1000® Growth Index (the Capitalization Index).Under normal circumstances, the Fund also invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of “growth” companies.
S000091548 [Member]
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of large-capitalization companies, primarily common stocks and securities that can be converted into common stocks. These companies have market capitalizations in the range of companies in the Russell 1000® Growth Index (the Capitalization Index), which ranged between $776.8 million and $4.8 trillion as of June 30, 2026. The market capitalization range and composition of companies in the Capitalization Index are subject to change. As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index. Under normal circumstances, the Fund also invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of “growth” companies. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding the future earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years. The Fund is non-diversified, which means that it can invest a greater percentage of its assets in the securities of fewer issuers than can a diversified fund. The Fund may invest in U.S. and foreign securities, including emerging market securities. The Fund may invest in foreign securities directly or indirectly through depositary receipts. The Fund may at times emphasize one or more sectors in selecting its investments. The Fund emphasizes the communication services and information technology sectors. The Fund may also invest in exchange-traded funds (ETFs). Columbia Management Investment Advisers, LLC (Columbia Management or the Investment Manager) serves as the investment manager for the Fund. Columbia Management is responsible for providing day-to-day portfolio management of a liquidity strategy sleeve of the Fund and is also responsible for oversight of the Fund’s subadvisers. Each subadviser employs its own large cap growth strategy and investment process in its respective sleeve that Columbia Management believes complement one another in pursuit of the Fund’s investment objective. The Fund’s subadvisers are J.P. Morgan Investment Management Inc. (JPMIM), Loomis, Sayles & Company, L.P. (Loomis Sayles) and Los Angeles Capital Management LLC (Los Angeles Capital). Columbia Management, subject to the oversight of the Fund’s Board of Trustees, determines, in its discretion, the allocation of the Fund’s assets to each sleeve, and may change these allocations at any time. One or more of the Fund’s subadvisers use quantitative methods to identify investment opportunities and construct their portion of the Fund’s portfolio.
Summary of Definition of Rule 35d-1 Term in Fund Name [Text Block]	Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of large-capitalization companies, primarily common stocks and securities that can be converted into common stocks. These companies have market capitalizations in the range of companies in the Russell 1000® Growth Index (the Capitalization Index), which ranged between $776.8 million and $4.8 trillion as of June 30, 2026. The market capitalization range and composition of companies in the Capitalization Index are subject to change. As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index. Under normal circumstances, the Fund also invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of “growth” companies. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding the future earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years.
Summary of Selection Criteria for Rule 35d-1 Term in Fund Name [Text Block]	These companies have market capitalizations in the range of companies in the Russell 1000® Growth Index (the Capitalization Index),which rangedbetween $776.8 million and $4.8 trillion as of June 30, 2026.The market capitalization range and composition of companies in the Capitalization Index are subject to change.As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding the future earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years.
Rule 35d-1 Eighty Percent Investment Policy [Text Block]	Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of large-capitalization companies, primarily common stocks and securities that can be converted into common stocks.Under normal circumstances, the Fund also invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of “growth” companies.

Investment Strategy

Mar. 31, 2026

Principal Investment Strategies

Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of large capitalization companies. These companies have market capitalizations in the range of companies in the Russell 1000® Growth Index (the Capitalization Index), which ranged between $776.8 million and $4.8 trillion as of June 30, 2026. The market capitalization range and composition of companies in the Capitalization Index are subject to change. As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index. Under normal circumstances, the Fund also invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of “growth” companies. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding the future earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years.

The Fund invests substantially in securities of U.S. issuers. The Fund generally invests in common stocks. The Fund may at times emphasize one or more sectors in selecting its investments. As of its most recent fiscal year end, the Fund had an investment emphasis in the information technology sector.

The Fund may also invest in exchange-traded funds (ETFs).

Summary of Definition of Rule 35d-1 Term in Fund Name [Text Block]

Summary of Selection Criteria for Rule 35d-1 Term in Fund Name [Text Block]

These companies have market capitalizations in the range of companies in the Russell 1000® Growth Index (the Capitalization Index), which ranged between $776.8 million and $4.8 trillion as of June 30, 2026.The market capitalization range and composition of companies in the Capitalization Index are subject to change.As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding the future earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years.

Rule 35d-1 Eighty Percent Investment Policy [Text Block]

Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of large capitalization companies.Under normal circumstances, the Fund also invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of “growth” companies.

S000021575 [Member]

Prospectus [Line Items]

Strategy [Heading]

Principal Investment Strategies

Strategy Narrative [Text Block]

Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in common stocks of U.S. and foreign companies that have market capitalizations in the range of companies in the Russell 1000® Growth Index (the Capitalization Index). The market capitalization range of the companies included within the Capitalization Index was $776.8 million to $4.8 trillion as of June 30, 2026. The market capitalization range and composition of companies in the Capitalization Index are subject to change. As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index. The Fund invests primarily in common stocks of companies believed to have the potential for long-term growth. Under normal circumstances, the Fund also invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of “growth” companies. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding the

future earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years. The Fund typically employs a focused portfolio investing style, which results in fewer holdings than a fund that seeks to achieve its investment objective by investing in a greater number of issuers. The Fund may invest directly in foreign securities or indirectly through depositary receipts. The Fund may at times emphasize one or more sectors in selecting its investments. As of its most recent fiscal year end, the Fund had an investment emphasis in the information technology sector.

Summary of Definition of Rule 35d-1 Term in Fund Name [Text Block]

Summary of Selection Criteria for Rule 35d-1 Term in Fund Name [Text Block]

The market capitalization range of the companies included within the Capitalization Index was $776.8 million to $4.8 trillion as of June 30, 2026.The market capitalization range and composition of companies in the Capitalization Index are subject to change.As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index.The Fund invests primarily in common stocks of companies believed to have the potential for long-term growth. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding thefuture earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years.

Rule 35d-1 Eighty Percent Investment Policy [Text Block]

S000091548 [Member]

Prospectus [Line Items]

Strategy [Heading]

Principal Investment Strategies

Strategy Narrative [Text Block]

Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of large-capitalization companies, primarily common stocks and securities that can be converted into common stocks. These companies have market capitalizations in the range of companies in the Russell 1000® Growth Index (the Capitalization Index), which ranged between $776.8 million and $4.8 trillion as of June 30, 2026. The market capitalization range and composition of companies in the Capitalization Index are subject to change. As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index. Under normal circumstances, the Fund also invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in equity securities of “growth” companies. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding the future earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years.

The Fund is non-diversified, which means that it can invest a greater percentage of its assets in the securities of fewer issuers than can a diversified fund. The Fund may invest in U.S. and foreign securities, including emerging market securities. The Fund may invest in foreign securities directly or indirectly through depositary receipts. The Fund may at times emphasize one or more sectors in selecting its investments. The Fund emphasizes the communication services and information technology sectors.

The Fund may also invest in exchange-traded funds (ETFs).

Columbia Management Investment Advisers, LLC (Columbia Management or the Investment Manager) serves as the investment manager for the Fund. Columbia Management is responsible for providing day-to-day portfolio management of a liquidity strategy sleeve of the Fund and is also responsible for oversight of the Fund’s subadvisers. Each subadviser employs its own large cap growth strategy and investment process in its respective sleeve that Columbia Management believes complement one another in pursuit of the Fund’s investment objective. The Fund’s subadvisers are J.P. Morgan Investment Management Inc. (JPMIM), Loomis, Sayles & Company, L.P. (Loomis Sayles) and Los Angeles Capital Management LLC (Los Angeles Capital). Columbia Management, subject to the oversight of the Fund’s Board of Trustees, determines, in its discretion, the allocation of the Fund’s assets to each sleeve, and may change these allocations at any time. One or more of the Fund’s subadvisers use quantitative methods to identify investment opportunities and construct their portion of the Fund’s portfolio.

Summary of Definition of Rule 35d-1 Term in Fund Name [Text Block]

Summary of Selection Criteria for Rule 35d-1 Term in Fund Name [Text Block]

These companies have market capitalizations in the range of companies in the Russell 1000® Growth Index (the Capitalization Index),which rangedbetween $776.8 million and $4.8 trillion as of June 30, 2026.The market capitalization range and composition of companies in the Capitalization Index are subject to change.As such, the size of the companies in which the Fund invests may change. The Fund may continue to hold a security even if the company’s market capitalization is no longer within the range of the Capitalization Index. The Fund considers “growth” companies to be those companies that are either constituents of an index constructed by a third party to identify companies with various characteristics of growth companies, have a higher Institutional Brokers' Estimate System (I/B/E/S) medium-term growth forecast (two year) than the median ranked stock within the company’s Global Industry Classification Standard (GICS) sector, or have a higher sales per share historical growth rate (five year) than the median ranked stock within the company’s GICS sector. The third-party broad-based index currently used to identify growth companies is the Russell 3000® Growth Index, although the Fund may change this index without prior notice. The I/B/E/S is a database used by brokers and investors to access the estimates made by stock analysts regarding the future earnings of publicly traded American companies. The I/B/E/S medium-term growth forecast is a measure of the average annualized EPS (earnings per share) growth forecast of contributing analysts/estimators for the forthcoming two years.

Rule 35d-1 Eighty Percent Investment Policy [Text Block]