Investment Strategy	Dec. 31, 2024
CTIVP - American Century Diversified Bond Fund
Prospectus [Line Items]
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 bonds and other debt securities. Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the Fund's 80% policy, consistent with the Fund's investment policies and limitations with respect to investments in derivatives. The subadvisers use the Bloomberg U.S. Aggregate Bond Index (the Index) as a guide in structuring the Fund and selecting its investments. The subadvisers manage the Fund to have similar overall interest rate risk to the Index. The Fund may invest up to 20% of its net assets in debt instruments that, at the time of purchase, are rated below investment grade or are unrated but determined to be of comparable quality (commonly referred to as “high yield” investments or “junk” bonds). The Fund may invest in securities issued or guaranteed by the U.S. Treasury and certain U.S. Government agencies or instrumentalities such as the Government National Mortgage Association (Ginnie Mae). Ginnie Mae is supported by the full faith and credit of the U.S. Government. Securities issued or guaranteed by other U.S. Government agencies or instrumentalities, such as the Federal National Mortgage Association (Fannie Mae), the Federal Home Loan Mortgage Corporation (Freddie Mac), and the Federal Home Loan Bank (FHLB) are not guaranteed by the U.S. Treasury or supported by the full faith and credit of the U.S. Government. However, they are authorized to borrow from the U.S. Treasury to meet their obligations. The Fund may invest up to 25% of its net assets in debt instruments of foreign issuers, including issuers in emerging markets. The Fund may invest in privately placed and other securities or instruments that are purchased and sold pursuant to Rule 144A or other exemptions under the Securities Act of 1933, as amended, subject to certain regulatory restrictions. The Fund may engage in transactions that have a leveraging effect on the Fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-selling securities, to adjust the Fund’s risk exposure. The Fund may purchase or sell securities on a when-issued, delayed delivery or forward commitment basis. Such securities may include mortgage-backed securities acquired or sold in the “to be announced” (TBA) market and those in a dollar roll transaction. The Fund’s investment strategy may involve the frequent trading of portfolio securities.

Investment Strategy

Dec. 31, 2024

Under normal circumstances, the Fund invests at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in bonds and other debt securities. Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the Fund's 80% policy, consistent with the Fund's investment policies and limitations with respect to investments in derivatives. The subadvisers use the Bloomberg U.S. Aggregate Bond Index (the Index) as a guide in structuring the Fund and selecting its investments. The subadvisers manage the Fund to have similar overall interest rate risk to the Index.

The Fund may invest up to 20% of its net assets in debt instruments that, at the time of purchase, are rated below investment grade or are unrated but determined to be of comparable quality (commonly referred to as “high yield” investments or “junk” bonds).

The Fund may invest in securities issued or guaranteed by the U.S. Treasury and certain U.S. Government agencies or instrumentalities such as the Government National Mortgage Association (Ginnie Mae). Ginnie Mae is supported by the full faith and credit of the U.S. Government. Securities issued or guaranteed by other U.S. Government agencies or instrumentalities, such as the Federal National Mortgage Association (Fannie Mae), the Federal Home Loan Mortgage Corporation (Freddie Mac), and the Federal Home Loan Bank (FHLB) are not guaranteed by the U.S. Treasury or supported by the full faith and credit of the U.S. Government. However, they are authorized to borrow from the U.S. Treasury to meet their obligations.

The Fund may invest up to 25% of its net assets in debt instruments of foreign issuers, including issuers in emerging markets.

The Fund may invest in privately placed and other securities or instruments that are purchased and sold pursuant to Rule 144A or other exemptions under the Securities Act of 1933, as amended, subject to certain regulatory restrictions.

The Fund may engage in transactions that have a leveraging effect on the Fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-selling securities, to adjust the Fund’s risk exposure.

The Fund may purchase or sell securities on a when-issued, delayed delivery or forward commitment basis. Such securities may include mortgage-backed securities acquired or sold in the “to be announced” (TBA) market and those in a dollar roll transaction.

The Fund’s investment strategy may involve the frequent trading of portfolio securities.