S000003877 [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 International Equity Fund | Class IA Shares | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 38.00% | 3.24% | 18.86% | (14.58%) | 9.09% | 12.35% | 25.55% | (18.95%) | 26.93% | (2.21%) |