Goodwill and intangible assets - Estimated Aggregate Future Amortization Expense of Core Deposit and Other Intangibles (Details) - USD ($) $ in Thousands |
Dec. 31, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Goodwill and Intangible Assets Disclosure [Abstract] | ||
| 2021 | $ 5,477 | |
| 2022 | 4,586 | |
| 2024 | 3,658 | |
| 2025 | 2,946 | |
| 2025 | 2,306 | |
| Thereafter | 3,453 | |
| Net Carrying Amount | $ 22,426 | $ 17,589 |