Income Taxes - Reconciliation of unrecognized tax benefits (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | |||
Unrecognized tax benefits, beginning of period | $ 627 | $ 938 | $ 847 |
Gross increases - tax positions in current period | 0 | 56 | 91 |
Decreases in prior year positions | (150) | (367) | 0 |
Unrecognized tax benefits, end of period | $ 477 | $ 627 | $ 938 |