Supplemental Balance Sheet and Income Statement Information - Accumulated other comprehensive income (loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Changes in accumulated other comprehensive income (loss)
Beginning balance			$ 590,656
Other comprehensive income (loss), net of tax	$ (1,611)	$ (2,248)	(933)	$ 252
Ending balance	439,241		439,241
Accumulated Other Comprehensive Income (Loss)
Changes in accumulated other comprehensive income (loss)
Beginning balance			(10,634)	(11,124)
Other comprehensive income (loss) before reclassifications			(1,053)	132
Amounts reclassified from accumulated other comprehensive income (loss)			120	120
Other comprehensive income (loss), net of tax			(933)	252
Ending balance	(11,567)	(10,872)	(11,567)	(10,872)
Gains (losses) on cash flow hedges
Changes in accumulated other comprehensive income (loss)
Beginning balance			2	2
Ending balance	2	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			1,428	(1,900)
Amounts reclassified from accumulated other comprehensive income (loss)			120	120
Other comprehensive income (loss), net of tax			1,548	(1,780)
Ending balance	(3,808)	(5,396)	(3,808)	(5,396)
Foreign currency items
Changes in accumulated other comprehensive income (loss)
Beginning balance			(5,280)	(7,510)
Other comprehensive income (loss) before reclassifications			(2,481)	2,032
Other comprehensive income (loss), net of tax			(2,481)	2,032
Ending balance	$ (7,761)	$ (5,478)	$ (7,761)	$ (5,478)