Comprehensive Income - Changes in accumulated other comprehensive loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024
COMPREHENSIVE INCOME
Balance at beginning		$ 245,585
Balance at ending	$ 248,062
Accumulated other comprehensive loss
COMPREHENSIVE INCOME
Balance at beginning	(17,701)	(17,934)	$ (18,330)	$ (17,311)
Other comprehensive loss before reclassifications	1,824	192	61	(1,092)
Amounts reclassified from accumulated other comprehensive loss	41	41	73	73
Net current period other comprehensive income	1,865	233	134	(1,019)
Balance at ending	(15,836)	(17,701)	(18,196)	(18,330)
Foreign Currency Translation Adjustments
COMPREHENSIVE INCOME
Balance at beginning	(11,479)	(11,671)	(9,046)	(7,954)
Other comprehensive loss before reclassifications	1,824	192	61	(1,092)
Net current period other comprehensive income	1,824	192	61	(1,092)
Balance at ending	(9,655)	(11,479)	(8,985)	(9,046)
Defined Benefit Pension Items
COMPREHENSIVE INCOME
Balance at beginning	(6,222)	(6,263)	(9,284)	(9,357)
Amounts reclassified from accumulated other comprehensive loss	41	41	73	73
Net current period other comprehensive income	41	41	73	73
Balance at ending	$ (6,181)	$ (6,222)	$ (9,211)	$ (9,284)