v3.26.1
S000003897 [Member] Expense Example - Putnam VT Focused International Equity Fund
Dec. 31, 2025
USD ($)
Class IA Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 80
Expense Example, with Redemption, 3 Years 260
Expense Example, with Redemption, 5 Years 456
Expense Example, with Redemption, 10 Years 1,021
Class IB Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 105
Expense Example, with Redemption, 3 Years 338
Expense Example, with Redemption, 5 Years 590
Expense Example, with Redemption, 10 Years $ 1,313