Supplemental Balance Sheet and Income Statement Information - Accumulated other comprehensive income (loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Changes in accumulated other comprehensive income (loss)
Beginning balance			$ 326,614
Other comprehensive income (loss), net of tax	$ (7)	$ 650	(100)	$ 748
Ending balance	250,371		250,371
Accumulated Other Comprehensive Income (Loss)
Changes in accumulated other comprehensive income (loss)
Beginning balance			(10,832)	(11,038)
Other comprehensive income (loss) before reclassifications			(181)	668
Amounts reclassified from accumulated other comprehensive income (loss)			81	80
Other comprehensive income (loss), net of tax			(100)	748
Ending balance	(10,932)	(10,290)	(10,932)	(10,290)
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			(3,606)	(3,767)
Amounts reclassified from accumulated other comprehensive income (loss)			81	80
Other comprehensive income (loss), net of tax			81	80
Ending balance	(3,525)	(3,687)	(3,525)	(3,687)
Foreign currency items
Changes in accumulated other comprehensive income (loss)
Beginning balance			(7,228)	(7,273)
Other comprehensive income (loss) before reclassifications			(181)	668
Other comprehensive income (loss), net of tax			(181)	668
Ending balance	$ (7,409)	$ (6,605)	$ (7,409)	$ (6,605)