This table describes the fees and expenses that you may pay as an investor in the Fund. The table does not reflect any fees or expenses imposed by your Contract or Qualified Plan, which are disclosed in your separate Contract prospectus or Qualified Plan disclosure documents. If the additional fees or expenses were reflected, the expenses set forth below would be higher.

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

April 30, 2025

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 40% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

40.00%

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

“Total annual Fund operating expenses” include acquired fund fees and expenses (expenses the Fund incurs indirectly through its investments in other investment companies) and may be higher than the ratio of expenses to average net assets shown in the Financial Highlights section of this prospectus because the ratio of expenses to average net assets does not include acquired fund fees and expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example illustrates the hypothetical expenses that you would incur over the time periods indicated, and assumes that:

■

you invest $10,000 in the Fund for the periods indicated,

■

your investment has a 5% return each year, and

■

the Fund’s total annual operating expenses remain the same as shown in the Annual Fund Operating Expenses table above.

The example does not reflect any fees and expenses that apply to your Contract or Qualified Plan. Inclusion of these charges would increase expenses for all periods shown.

Since the waivers and/or reimbursements shown in the Annual Fund Operating Expenses table above expire as indicated in the preceding table, they are only reflected in the 1 year example and the first year of the other examples. Although your actual costs may be higher or lower, based on the assumptions listed above, your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal Investment Strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

Under normal circumstances, the Fund invests at least 65% of its net assets in foreign companies in developed markets (for example, Japan, Canada and the United Kingdom) and in emerging markets (for example, China, India and Brazil).

Under normal circumstances, the Fund invests a majority of its net assets in the common stock of small- and mid-sized companies with market capitalizations generally in the range of market capitalizations in the MSCI ACWI ex USA Small Cap Growth Index (Net), the Fund's primary benchmark, (the Index) at the time of purchase (between $114.3 million and $9.2 billion as of March 31, 2024). The market capitalization range and composition of companies in the Index are subject to change. As such, the size of the companies in which the Fund invests may change. The Fund determines a company’s market capitalization at the time of investment. As long as a majority of its net assets are invested in companies within the market capitalization range of the Index, the Fund may continue to hold and make new investments in a security even if the company’s market capitalization grows beyond the market capitalization of the largest company within the range of the Index or falls below the market capitalization of the smallest company within the Index. The Investment Manager from time to time emphasizes one or more sectors in selecting the Fund’s investments, including the industrials and information technology sectors.

Columbia Wanger Asset Management, LLC, the Fund's investment adviser (the Investment Manager), believes that stocks of small- and mid-sized companies, which generally are not as well known by financial analysts as larger companies, may offer higher return potential than stocks of larger companies.

The Investment Manager typically seeks companies with:

■

A strong business franchise that offers growth potential.

■

Products and services in which the company has a competitive advantage.

■

A stock price the Investment Manager believes is reasonable relative to the assets and earning power of the company.

The Investment Manager may sell a portfolio holding if the security reaches the Investment Manager's price target, if the company has a deterioration of fundamentals, such as failing to meet key operating benchmarks, or if the Investment Manager believes other securities are more attractive. The Investment Manager also may sell a portfolio holding to fund redemptions.

Risk [Heading]

rr_RiskHeading

Principal Risks

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance Information

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table show you how the Fund has performed in the past, and can help you understand the risks of investing in the Fund. The bar chart shows how the Fund’s performance has varied for each full calendar year shown. The table below the bar chart compares the Fund’s returns for the periods shown with those of the MSCI ACWI ex USA Small Cap Growth Index (Net), the Fund's primary benchmark, and those of the MSCI ACWI ex USA Small Cap Index (Net), the Fund's secondary benchmark. The MSCI ACWI ex USA Small Cap Growth Index (Net) captures small-cap securities exhibiting overall growth style characteristics across 22 developed market countries and 24 emerging market countries. The MSCI ACWI ex USA Small Cap Index (Net) captures small-cap representation across 22 of 23 developed market countries (excluding the United States) and 24 emerging market countries. As of March 31, 2024, the MSCI ACWI ex USA Small Cap Index (Net) had 4,424 constituents and covered approximately 14% of the global equity opportunity set outside the United States.

The returns shown do not reflect any fees and expenses imposed under your Contract or Qualified Plan and would be lower if they did.

The Fund’s past performance is no guarantee of how the Fund will perform in the future. Daily and month-end performance information is available by calling the Investment Manager at 800.345.6611 or visiting columbiathreadneedleus.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800.345.6611

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

columbiathreadneedleus.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The Fund’s past performance is no guarantee of how the Fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Year by Year Total Return (%) as of December 31 Each Year

Bar Chart Does Not Reflect Sales Loads [Text]

rr_BarChartDoesNotReflectSalesLoads

The returns shown do not reflect any fees and expenses imposed under your Contract or Qualified Plan and would be lower if they did.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best and Worst Quarterly Returns During the Period Shown in the Bar Chart Best 2nd Quarter 2020 26.92% Worst 1st Quarter 2020 -29.50%

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns (for periods ended December 31, 2023)

Wanger International | Risk Lose Money [Member]

Risk/Return:

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

There is no assurance that the Fund will achieve its investment objective and you may lose money.

Wanger International | Risk Not Insured Depository Institution [Member]

Risk/Return:

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Wanger International | Active Management Risk [Member]

Risk/Return:

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

Active Management Risk. The Investment Manager’s active management of the Fund could cause the Fund to underperform its benchmark index and/or other funds with similar investment objectives and/or strategies.

Wanger International | Market Risk [Member]

Risk/Return:

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

Market Risk. The Fund may incur losses due to declines in the value of one or more securities in which it invests. These declines may be due to factors affecting a particular issuer, or the result of, among other things, political, regulatory, market, economic or social developments affecting the relevant market(s) more generally. In addition, turbulence in financial markets and reduced liquidity in equity, credit and/or fixed income markets may negatively affect many issuers, which could adversely affect the Fund’s ability to price or value hard-to-value assets in thinly traded and closed markets and could cause significant redemptions and operational challenges. Global economies and financial markets are increasingly interconnected, and conditions and events in one country, region or financial market may adversely impact issuers in a different country, region or financial market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies worldwide. As a result, local, regional or global events such as terrorism, war, other

conflicts, natural disasters, disease/virus outbreaks and epidemics or other public health issues, recessions, depressions or other events – or the potential for such events – could have a significant negative impact on global economic and market conditions.

Wanger International | Small and Mid Cap Company Securities Risk [Member]

Risk/Return:

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

Small- and Mid-Cap Company Securities Risk. Investments in small- and mid-cap companies often involve greater risks than investments in larger, more established companies because small- and mid-cap companies tend to have less predictable earnings and may lack the management experience, financial resources, product diversification and competitive strengths of larger companies. Securities of small- and mid-cap companies may be less liquid and more volatile than the securities of larger companies.

Wanger International | Growth Securities Risk [Member]

Risk/Return:

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

Growth Securities Risk. Growth securities typically trade at a higher multiple of earnings than other types of equity securities. Accordingly, the market values of growth securities may never reach their expected market value and may decline in price. In addition, growth securities, at times, may not perform as well as value securities or the stock market in general, and may be out of favor with investors for varying periods of time. Growth securities may also be sensitive to movements in interest rates.

Wanger International | Foreign Securities Risk [Member]

Risk/Return:

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

Foreign Securities Risk. Investments in or exposure to securities of foreign companies may involve heightened risks relative to investments in or exposure to securities of U.S. companies. Investing in securities of foreign companies subjects the Fund to the risks associated with an issuer’s (and any of its related companies’) country of organization and places of business operations, including risks related to political, regulatory, economic, social, diplomatic and other conditions or events (including, for example, military confrontations and actions, war, other conflicts, terrorism and disease/virus outbreaks and epidemics) occurring in the country or region, as well as risks associated with less developed custody and settlement practices. Foreign securities may be more volatile and less liquid than securities of U.S. companies, and are subject to the risks associated with potential imposition of economic and other sanctions against a particular foreign country, its nationals or industries or businesses within the country. In addition, foreign governments may impose withholding or other taxes on the Fund’s income, capital gains or proceeds from the disposition of foreign securities, which could reduce the Fund’s return on such securities.

Operational and Settlement Risks of Foreign Securities. The Fund’s foreign securities are generally held outside the United States in the primary market for the securities in the custody of foreign sub-custodians. Some countries have limited governmental oversight and regulation, which increases the risk of corruption and fraud and the possibility of losses to the Fund. In particular, under certain circumstances, foreign securities may settle on a delayed delivery basis, meaning that the Fund may be required to make payment for securities before the Fund has actually received delivery of the securities or deliver securities prior to the receipt of payment. As a result, there is a risk that the security will not be delivered to the Fund or that payment will not be received. Losses can also result from lost, stolen or counterfeit securities; defaults by brokers and banks; failures or defects of the settlement system; or poor and improper record keeping by registrars and issuers.

Share Blocking. In certain non-U.S. markets, an issuer’s securities are blocked from trading for a specified number of days before and, in certain instances, after a shareholder meeting. The blocking period can last up to several weeks. Share blocking may prevent the Fund from buying or selling securities during this period. As a consequence of these restrictions, the Investment Manager, on behalf of the Fund, may abstain from voting proxies in markets that require share blocking.

Wanger International | Emerging Market Securities Risk [Member]

Risk/Return:

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

Emerging Market Securities Risk. Securities issued by foreign governments or companies in emerging market countries, such as China, Russia and certain countries in Eastern Europe, the Middle East, Asia, Latin America or Africa, are more likely to have greater exposure to the risks of investing in foreign securities that are described in Foreign Securities Risk. In addition, emerging market countries are more likely to experience instability resulting, for example, from rapid changes or developments in social, political, economic or other conditions. Their economies are usually less mature and their securities markets are typically less developed with more limited trading activity (i.e., lower trading volumes and less liquidity) than more developed countries. Emerging market securities tend to be more volatile, and may be more susceptible to market manipulation, than securities in more developed markets. Many emerging market countries are heavily dependent on international trade and have fewer trading partners, which makes them more sensitive to world commodity prices and economic downturns in other countries, and some have a higher risk of currency devaluations. Due to the differences in the nature and quality of financial information of

issuers of emerging market securities, including auditing and financial reporting standards, financial information and disclosures about such issuers may be unavailable or, if made available, may be considerably less reliable than publicly available information about other foreign securities.

Operational and Settlement Risks of Securities in Emerging Markets. Foreign sub-custodians in emerging markets may be recently organized, lack extensive operating experience or lack effective government oversight or regulation. In addition, there may be legal restrictions or limitations on the ability of the Fund to recover assets held in custody by a foreign sub-custodian in the event of the bankruptcy of the sub-custodian. There may also be a greater risk that settlement may be delayed and that cash or securities of the Fund may be lost because of failures of or defects in the system, including fraud or corruption. Settlement systems in emerging markets also have a higher risk of failed trades.

Risks Related to Currencies and Corporate Actions in Emerging Markets. Risks related to currencies and corporate actions are also greater in emerging market countries than in developed countries. Emerging market currencies may not have an active trading market and are subject to a higher risk of currency devaluations.

Risks Related to Corporate and Securities Laws in Emerging Markets. Securities laws in emerging markets may be relatively new and unsettled and, consequently, there is a risk of rapid and unpredictable change in laws regarding foreign investment, securities regulation, title to securities and shareholder rights.

Wanger International | Liquidity and Trading Volume Risk [Member]

Risk/Return:

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

Liquidity and Trading Volume Risk. Due to market conditions, including uncertainty regarding the price of a security, it may be difficult for the Fund to buy or sell portfolio securities at a desirable time or price, which could result in investment losses. This risk of portfolio illiquidity is heightened with respect to small- and mid-cap securities, generally, and foreign small- and mid-cap securities in particular. The Fund may have to lower the selling price, liquidate other investments, or forego another, more appealing investment opportunity as a result of illiquidity in the markets. The Fund may also be limited in its ability to execute favorable trades in portfolio securities in response to changes in share prices and fundamentals, and may be forced to dispose of securities under disadvantageous circumstances and at a loss. As the Fund grows in size or, conversely, if it faces significant redemption pressure, these considerations take on increasing significance and may adversely impact performance.

Wanger International | Geographic Focus Risk [Member]

Risk/Return:

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

Geographic Focus Risk. The Fund may be particularly susceptible to risks related to economic, political, regulatory or other events or conditions affecting issuers and countries within the specific geographic regions in which the Fund invests. The Fund’s NAV may be more volatile than the NAV of a more geographically diversified fund.

■

Asia Pacific Region. Many of the countries in the Asia Pacific region are considered underdeveloped or developing, including from a political, economic and/or social perspective, and may have relatively unstable governments and economies based on limited business, industries and/or natural resources or commodities. Events in any one country within the region may impact other countries in the region or the region as a whole. As a result, events in the region will generally have a greater effect on the Fund than if the Fund were more geographically diversified. This could result in increased volatility in the value of the Fund’s investments and losses for the Fund. Also, securities of some companies in the region can be less liquid than U.S. or other foreign securities, potentially making it difficult for the Fund to sell such securities at a desirable time and price.

■

Europe. The Fund is particularly susceptible to risks related to economic, political, regulatory or other events or conditions, including acts of war or other conflicts in the region, affecting issuers and countries in Europe. Countries in Europe are often closely connected and interdependent, and events in one European country can have an adverse impact on, and potentially spread to, other European countries. In addition, significant private or public debt problems in a single European Union (EU) country can pose economic risks to the EU as a whole. As a result, the Fund’s NAV may be more volatile than the NAV of a more geographically diversified fund. If securities of issuers in Europe fall out of favor, it may cause the Fund to underperform other funds that do not focus their investments in this region of the world. Any uncertainty caused by the departure of the United Kingdom (UK) from the EU, which occurred in January 2020, could have negative impacts on the UK and the EU, as well as other European economies and the broader global economy. These could include negative impacts on currencies and financial markets as well as increased volatility and illiquidity, and potentially lower economic growth in markets in Europe, which could adversely affect the value of your investment in the Fund.

Wanger International | Sector Risk [Member]

Risk/Return:

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

Sector Risk. At times, the Fund may have a significant portion of its assets invested in securities of companies conducting business in an industry or related group of industries within one or more economic sectors, including the industrials and information technology sectors. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund vulnerable to unfavorable developments in that industry, group of industries or economic sector.

■

Industrials Sector. The Fund is vulnerable to the particular risks that may affect companies in the industrials sector. Companies in the industrials sector are subject to certain risks, including changes in supply and demand for their specific product or service and for industrial sector products in general, including decline in demand for such products due to rapid technological developments and frequent new product introduction. Performance of such companies may be affected by factors including government regulation, world events, economic conditions and risks for environmental damage and product liability claims.

■

Information Technology Sector. The Fund is vulnerable to the particular risks that may affect companies in the information technology sector. Companies in the information technology sector are subject to certain risks, including the risk that new services, equipment or technologies will not be accepted by consumers and businesses or will become rapidly obsolete. Performance of such companies may be affected by factors including obtaining and protecting patents (or the failure to do so) and significant competitive pressures, including aggressive pricing of their products or services, new market entrants, competition for market share and short product cycles due to an accelerated rate of technological developments. Such competitive pressures may lead to limited earnings and/or falling profit margins. As a result, the value of their securities may fall or fail to rise. In addition, many information technology sector companies have limited operating histories and prices of these companies’ securities historically have been more volatile than other securities, especially over the short term. Some companies in the information technology sector are facing increased government and regulatory scrutiny and may be subject to adverse government or regulatory action, which could negatively impact the value of their securities.

Wanger International | Foreign Currency Risk [Member]

Risk/Return:

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

Foreign Currency Risk. The performance of the Fund may be materially affected positively or negatively by foreign currency strength or weakness relative to the U.S. dollar, particularly if the Fund invests a significant percentage of its assets in foreign securities or other assets denominated in currencies other than the U.S. dollar.

Wanger International | Issuer Risk [Member]

Risk/Return:

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

Issuer Risk. An issuer in which the Fund invests may perform poorly, and the value of its securities may therefore decline, which may negatively affect the Fund’s performance. Underperformance of an issuer may be caused by poor management decisions, competitive pressures, breakthroughs in technology, reliance on suppliers, labor problems or shortages, corporate restructurings, fraudulent disclosures, natural disasters, military confrontations and actions, war, other conflicts, terrorism, disease/virus outbreaks and epidemics or other events, conditions and factors.

Wanger International | Wanger International

Risk/Return:

rr_RiskReturnAbstract

Management fees

rr_ManagementFeesOverAssets

0.99%

Distribution and/or service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.28%

Total annual Fund operating expenses

rr_ExpensesOverAssets

1.27%

^[1]

Less: Fee waivers and/or expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.13%)

^[2]

Total annual Fund operating expenses after fee waivers and/or expense reimbursements

rr_NetExpensesOverAssets

1.14%

1 year

rr_ExpenseExampleYear01

$ 116

3 years

rr_ExpenseExampleYear03

390

5 years

rr_ExpenseExampleYear05

684

10 years

rr_ExpenseExampleYear10

1,522

1 year

rr_ExpenseExampleNoRedemptionYear01

116

3 years

rr_ExpenseExampleNoRedemptionYear03

390

5 years

rr_ExpenseExampleNoRedemptionYear05

684

10 years

rr_ExpenseExampleNoRedemptionYear10

$ 1,522

2014

rr_AnnualReturn2014

(4.40%)

2015

rr_AnnualReturn2015

0.10%

2016

rr_AnnualReturn2016

(1.41%)

2017

rr_AnnualReturn2017

32.91%

2018

rr_AnnualReturn2018

(17.70%)

2019

rr_AnnualReturn2019

29.99%

2020

rr_AnnualReturn2020

14.36%

2021

rr_AnnualReturn2021

18.81%

2022

rr_AnnualReturn2022

(33.84%)

2023

rr_AnnualReturn2023

16.95%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2020

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

26.92%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(29.50%)

1 Year

rr_AverageAnnualReturnYear01

16.95%

5 Years

rr_AverageAnnualReturnYear05

6.45%

10 Years

rr_AverageAnnualReturnYear10

3.50%

Share Class Inception Date

rr_AverageAnnualReturnInceptionDate

May 03, 1995

Wanger International | MSCI ACWI ex USA Small Cap Growth Index (Net) (reflects reinvested dividends net of withholding taxes but reflects no deductions for fees, expenses or other taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

14.11%

5 Years

rr_AverageAnnualReturnYear05

7.71%

10 Years

rr_AverageAnnualReturnYear10

4.95%

Wanger International | MSCI ACWI ex USA Small Cap Index (Net) (reflects reinvested dividends net of withholding taxes but reflects no deductions for fees, expenses or other taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

15.66%

5 Years

rr_AverageAnnualReturnYear05

7.89%

10 Years

rr_AverageAnnualReturnYear10

4.88%

[1]

[2]

Columbia Wanger Asset Management, LLC (the Investment Manager) has contractually agreed to waive fees and reimburse certain expenses of the Fund, through April 30, 2025, so that ordinary operating expenses (excluding transaction costs and certain other investment-related expenses, interest and fees on borrowings and expenses associated with the Fund’s investment in other investment companies, if any), do not exceed the annual rate of 1.14%. This arrangement may only be amended or terminated with approval from the Fund’s Board of Trustees and the Investment Manager.