Investment Strategy - Eaton Vance VT Floating-Rate Income Fund - Eaton Vance VT Floating-Rate Income 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 any borrowings for investment purposes) in income producing floating rate loans and other floating rate debt securities. Floating rate loans and other floating rate debt securities are debt instruments or similar obligations issued by companies or other entities that pay a floating rate of interest, which resets or adjusts periodically, based on a reference or other benchmark rate. The Fund invests primarily in senior floating rate loans of domestic and foreign borrowers (“Senior Loans”). Senior Loans typically are secured with specific collateral and have a claim on the assets and/or stock of the borrower that is senior to subordinated debtholders and stockholders of the borrower. Loans usually are of below investment grade quality and have below investment grade credit ratings, such ratings are associated with securities having high risk, speculative characteristics (sometimes referred to as “junk”). The Fund may also invest in secured and unsecured subordinated loans, second lien loans and subordinated bridge loans (collectively, “Junior Loans”), other floating rate debt securities, fixed-income debt obligations and money market instruments. Other floating rate debt securities, fixed-income debt securities and money market instruments may include: bonds, notes and debentures issued by corporations; debt securities issued or guaranteed by the U.S. Government or one of its agencies or instrumentalities; and commercial paper. Money market instruments with a remaining maturity of less than 60 days are deemed floating rate debt securities. Senior Loans and Junior Loans are referred to together herein as “loans.” The Fund may invest up to 25% of its total assets in U.S. dollar denominated foreign Senior Loans. The investment adviser seeks to maintain broad borrower and industry diversification among the Fund’s loans. When selecting loans, the investment adviser seeks to implement a systematic risk-weighted approach that utilizes fundamental analysis of risk/return characteristics. Loans may be sold, if in the opinion of the investment adviser, the risk-return profile deteriorates or to pursue more attractive investment opportunities. Preservation of capital is considered when consistent with the Fund’s investment objective. When deemed by the Adviser to be relevant to its evaluation of creditworthiness and when applicable information is available, the Adviser considers environmental, social and/or governance issues (referred to as ESG) which may impact the prospects of an issuer (or obligor) or financial performance of an obligation. When considered, one or more ESG issues are taken into account alongside other factors in the investment decision-making process and are not the sole determinant of whether an investment can be made or will remain in the Fund’s portfolio.
Strategy Portfolio Concentration [Text]	Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in income producing floating rate loans and other floating rate debt securities. Floating rate loans and other floating rate debt securities are debt instruments or similar obligations issued by companies or other entities that pay a floating rate of interest, which resets or adjusts periodically, based on a reference or other benchmark rate. The Fund invests primarily in senior floating rate loans of domestic and foreign borrowers (“Senior Loans”). Senior Loans typically are secured with specific collateral and have a claim on the assets and/or stock of the borrower that is senior to subordinated debtholders and stockholders of the borrower. Loans usually are of below investment grade quality and have below investment grade credit ratings, such ratings are associated with securities having high risk, speculative characteristics (sometimes referred to as “junk”).

Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in income producing floating rate loans and other floating rate debt securities. Floating rate loans and other floating rate debt securities are debt instruments or similar obligations issued by companies or other entities that pay a floating rate of interest, which resets or adjusts periodically, based on a reference or other benchmark rate. The Fund invests primarily in senior floating rate loans of domestic and

foreign borrowers (“Senior Loans”). Senior Loans typically are secured with specific collateral and have a claim on the assets and/or stock of the borrower that is senior to subordinated debtholders and stockholders of the borrower. Loans usually are of below investment grade quality and have below investment grade credit ratings, such ratings are associated with securities having high risk, speculative characteristics (sometimes referred to as “junk”).

The Fund may also invest in secured and unsecured subordinated loans, second lien loans and subordinated bridge loans (collectively, “Junior Loans”), other floating rate debt securities, fixed-income debt obligations and money market instruments. Other floating rate debt securities, fixed-income debt securities and money market instruments may include: bonds, notes and debentures issued by corporations; debt securities issued or guaranteed by the U.S. Government or one of its agencies or instrumentalities; and commercial paper. Money market instruments with a remaining maturity of less than 60 days are deemed floating rate debt securities. Senior Loans and Junior Loans are referred to together herein as “loans.” The Fund may invest up to 25% of its total assets in U.S. dollar denominated foreign Senior Loans.

The investment adviser seeks to maintain broad borrower and industry diversification among the Fund’s loans. When selecting loans, the investment adviser seeks to implement a systematic risk-weighted approach that utilizes fundamental analysis of risk/return characteristics. Loans may be sold, if in the opinion of the investment adviser, the risk-return profile deteriorates or to pursue more attractive investment opportunities. Preservation of capital is considered when consistent with the Fund’s investment objective. When deemed by the Adviser to be relevant to its evaluation of creditworthiness and when applicable information is available, the Adviser considers environmental, social and/or governance issues (referred to as ESG) which may impact the prospects of an issuer (or obligor) or financial performance of an obligation. When considered, one or more ESG issues are taken into account alongside other factors in the investment decision-making process and are not the sole determinant of whether an investment can be made or will remain in the Fund’s portfolio.