Supplemental Balance Sheet and Income Statement Information - Accumulated other comprehensive income (loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Changes in accumulated other comprehensive income (loss)
Beginning balance			$ 326,614
Other comprehensive income (loss), net of tax	$ 88	$ (132)	(12)	$ 616
Ending balance	191,363		191,363
Accumulated Other Comprehensive Income (Loss)
Changes in accumulated other comprehensive income (loss)
Beginning balance			(10,832)	(11,038)
Other comprehensive income (loss) before reclassifications			(133)	496
Amounts reclassified from accumulated other comprehensive income (loss)			121	120
Other comprehensive income (loss), net of tax			(12)	616
Ending balance	(10,844)	(10,422)	(10,844)	(10,422)
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)			121	120
Other comprehensive income (loss), net of tax			121	120
Ending balance	(3,485)	(3,647)	(3,485)	(3,647)
Foreign currency items
Changes in accumulated other comprehensive income (loss)
Beginning balance			(7,228)	(7,273)
Other comprehensive income (loss) before reclassifications			(133)	496
Other comprehensive income (loss), net of tax			(133)	496
Ending balance	$ (7,361)	$ (6,777)	$ (7,361)	$ (6,777)