v3.26.1
S000003893 [Member] Expense Example - Putnam VT Diversified Income Fund
Dec. 31, 2025
USD ($)
Class IA Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 82
Expense Example, with Redemption, 3 Years 256
Expense Example, with Redemption, 5 Years 444
Expense Example, with Redemption, 10 Years 990
Class IB Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 107
Expense Example, with Redemption, 3 Years 334
Expense Example, with Redemption, 5 Years 579
Expense Example, with Redemption, 10 Years $ 1,282