S000028691 [Member] Investment Strategy - CTIVP - Westfield Mid Cap Growth Fund	Dec. 31, 2025
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 mid-capitalization companies. The Fund defines mid-capitalization companies as those companies with a market capitalization that falls within the range of the companies that comprise the Russell Midcap® Growth Index (the Capitalization Index). The market capitalization range of the companies included within the Capitalization Index was $134.5 million to $95.9 billion as of March 31, 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 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 may at times emphasize one or more sectors in selecting its investments, including the consumer discretionary, health care, industrials, and information technology sectors.

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 mid-capitalization companies. The Fund defines mid-capitalization companies as those companies with a market capitalization that falls within the range of the companies that comprise the Russell Midcap® Growth Index (the Capitalization Index). The market capitalization range of the companies included within the Capitalization Index was $134.5 million to $95.9 billion as of March 31, 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 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 may at times emphasize one or more sectors in selecting its investments, including the consumer discretionary, health care, industrials, and information technology sectors.