Income Taxes - Unrecognized tax benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Taxes
Recognized tax benefit	$ 800	$ 700	$ 700
Unrecognized tax benefits	2,077	1,836	4,314
Accrued interest and penalties on unrecognized tax benefits	2,400	2,100	2,100
Interest and penalties recorded on unrecognized tax benefits	(300)	(0)	(200)
Reconciliation of total amounts of unrecognized tax benefits
Balance at beginning of the period	1,836	4,314	1,476
Gross increases - tax positions in current period	460	151	1,470
Settlement	(90)
Balance at end of the period	2,077	1,836	4,314
Deferred taxes provided for withholding or other taxes for repatriation of foreign earnings	0
Undistributed earnings from foreign subsidiaries	132,900
Foreign withholding taxes on the undistributed earnings	7,100	6,000
Undistributed Foreign Earnings	1,100	300	1,600
Prior tax period 1
Reconciliation of total amounts of unrecognized tax benefits
Gross increases - tax positions in prior period			1,378
Gross decreases - tax positions in prior period		(21)
Prior tax period 2
Reconciliation of total amounts of unrecognized tax benefits
Gross decreases - tax positions in prior period	$ (129)	$ (2,608)	$ (10)