S000003896 [Member] Expense Example, No Redemption - Putnam VT Global Asset Allocation Fund |
Dec. 31, 2025
USD ($)
|
|---|---|
| Class IA Shares | |
| Prospectus [Line Items] | |
| Expense Example, No Redemption, 1 Year | $ 86 |
| Expense Example, No Redemption, 3 Years | 272 |
| Expense Example, No Redemption, 5 Years | 474 |
| Expense Example, No Redemption, 10 Years | 1,058 |
| Class IB Shares | |
| Prospectus [Line Items] | |
| Expense Example, No Redemption, 1 Year | 111 |
| Expense Example, No Redemption, 3 Years | 351 |
| Expense Example, No Redemption, 5 Years | 610 |
| Expense Example, No Redemption, 10 Years | $ 1,351 |