S000003874 [Member] Annual Total Returns |
12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Putnam VT Global Health Care Fund | Class IA Shares | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 15.34% | 1.70% | 9.39% | (4.44%) | 19.77% | 16.47% | 30.58% | (0.29%) | 15.60% | (11.14%) |