Derivative instruments - Forward Contract Hedges in the Consolidated Balance Sheets (Details) - Foreign exchange forward - Designated as hedging instrument - Cash flow hedging - USD ($) $ in Thousands |
Dec. 31, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Other current assets | ||
| Derivative [Line Items] | ||
| Foreign currency forward contracts designated as cash flow hedge | $ 404 | |
| Other accrued liabilities | ||
| Derivative [Line Items] | ||
| Foreign currency forward contracts designated as cash flow hedge | $ 185 |