S000003881 [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 Sustainable Future Fund | Class IA Shares | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 2.87% | 15.23% | 28.83% | (33.85%) | 6.33% | 52.99% | 30.32% | (4.64%) | 10.94% | 13.23% |