Supplemental Balance Sheet and Income Statement Information - Accumulated other comprehensive income (loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Changes in accumulated other comprehensive income (loss)
Beginning balance	$ 590,656
Other comprehensive income (loss), net of tax	(404)	$ 490	$ 664
Ending balance	368,956	590,656
Accumulated Other Comprehensive Income
Changes in accumulated other comprehensive income (loss)
Beginning balance	(10,634)	(11,124)
Other comprehensive income (loss) before reclassifications	(564)	330
Amounts reclassified from accumulated other comprehensive income (loss)	160	160
Other comprehensive income (loss), net of tax	(404)	490
Ending balance	(11,038)	(10,634)	(11,124)
Gains (losses) on cash flow hedges
Changes in accumulated other comprehensive income (loss)
Beginning balance	2	2
Ending balance	2	2	2
Defined benefit pension plan items
Changes in accumulated other comprehensive income (loss)
Beginning balance	(5,356)	(3,616)
Other comprehensive income (loss) before reclassifications	1,429	(1,900)
Amounts reclassified from accumulated other comprehensive income (loss)	160	160
Other comprehensive income (loss), net of tax	1,589	(1,740)
Ending balance	(3,767)	(5,356)	(3,616)
Foreign currency items
Changes in accumulated other comprehensive income (loss)
Beginning balance	(5,280)	(7,510)
Other comprehensive income (loss) before reclassifications	(1,993)	2,230
Other comprehensive income (loss), net of tax	(1,993)	2,230
Ending balance	$ (7,273)	$ (5,280)	$ (7,510)