Comprehensive Income - Changes in accumulated other comprehensive loss (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Comprehensive Income
Foreign Currency Translation Adjustments, Beginning balance			$ (7,954)	$ (8,596)
Foreign Currency Translation Adjustments, Other comprehensive income (loss) before reclassifications			(1,031)	(44)
Foreign Currency Translation Adjustments, Net current period other comprehensive (loss) income			(1,031)	(44)
Foreign Currency Translation Adjustments, Ending balance	$ (8,985)	$ (8,640)	(8,985)	(8,640)
Defined Benefit Pension Items, Beginning balance			(9,357)	(11,597)
Defined Benefit Pension Items, Amounts reclassified from accumulated other comprehensive loss	73	84	146	183
Net current period other comprehensive (loss) income	73	84	146	183
Defined Benefit Pension Items, Ending balance	(9,211)	(11,414)	(9,211)	(11,414)
Beginning balance			(17,311)	(20,193)
Other comprehensive loss before reclassifications			(1,031)	(44)
Amounts reclassified from accumulated other comprehensive loss			146	183
Net current period other comprehensive income			(885)	139
Ending balance	$ (18,196)	$ (20,054)	$ (18,196)	$ (20,054)