S000003874 [Member] Expense Example, No Redemption - Putnam VT Global Health Care Fund |
Dec. 31, 2025
USD ($)
|
|---|---|
| Class IA Shares | |
| Prospectus [Line Items] | |
| Expense Example, No Redemption, 1 Year | $ 77 |
| Expense Example, No Redemption, 3 Years | 240 |
| Expense Example, No Redemption, 5 Years | 417 |
| Expense Example, No Redemption, 10 Years | 930 |
| Class IB Shares | |
| Prospectus [Line Items] | |
| Expense Example, No Redemption, 1 Year | 102 |
| Expense Example, No Redemption, 3 Years | 318 |
| Expense Example, No Redemption, 5 Years | 552 |
| Expense Example, No Redemption, 10 Years | $ 1,224 |