S000003880 [Member] Expense Example, No Redemption - Putnam VT Core Equity Fund |
Dec. 31, 2025
USD ($)
|
|---|---|
| Class IA Shares | |
| Prospectus [Line Items] | |
| Expense Example, No Redemption, 1 Year | $ 68 |
| Expense Example, No Redemption, 3 Years | 214 |
| Expense Example, No Redemption, 5 Years | 373 |
| Expense Example, No Redemption, 10 Years | 834 |
| Class IB Shares | |
| Prospectus [Line Items] | |
| Expense Example, No Redemption, 1 Year | 94 |
| Expense Example, No Redemption, 3 Years | 294 |
| Expense Example, No Redemption, 5 Years | 510 |
| Expense Example, No Redemption, 10 Years | $ 1,132 |