Comprehensive Income - Changes in accumulated other comprehensive loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
COMPREHENSIVE INCOME
Balance at beginning	$ 245,585
Balance at ending	248,550
Accumulated other comprehensive loss
COMPREHENSIVE INCOME
Balance at beginning	(17,934)	$ (17,311)
Other comprehensive loss before reclassifications	192	(1,092)
Amounts reclassified from accumulated other comprehensive loss	41	73
Net current period other comprehensive income	233	(1,019)
Balance at ending	(17,701)	(18,330)
Foreign Currency Translation Adjustments
COMPREHENSIVE INCOME
Balance at beginning	(11,671)	(7,954)
Other comprehensive loss before reclassifications	192	(1,092)
Net current period other comprehensive income	192	(1,092)
Balance at ending	(11,479)	(9,046)
Defined Benefit Pension Items
COMPREHENSIVE INCOME
Balance at beginning	(6,263)	(9,357)
Amounts reclassified from accumulated other comprehensive loss	41	73
Net current period other comprehensive income	41	73
Balance at ending	$ (6,222)	$ (9,284)