COMPREHENSIVE INCOME - Changes in accumulated other comprehensive loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
COMPREHENSIVE INCOME
Balance at beginning	$ 245,585
Balance at ending	239,568	$ 245,585
Accumulated other comprehensive loss
COMPREHENSIVE INCOME
Balance at beginning	(17,934)	(17,311)
Other comprehensive loss before reclassifications	3,971	(931)
Amounts reclassified from accumulated other comprehensive loss	109	308
Net current period other comprehensive income	4,080	(623)
Balance at ending	(13,854)	(17,934)
Foreign Currency Translation Adjustments
COMPREHENSIVE INCOME
Balance at beginning	(11,671)	(7,954)
Other comprehensive loss before reclassifications	2,391	(3,717)
Net current period other comprehensive income	2,391	(3,717)
Balance at ending	(9,280)	(11,671)
Defined Benefit Pension Items
COMPREHENSIVE INCOME
Balance at beginning	(6,263)	(9,357)
Other comprehensive loss before reclassifications	1,580	2,786
Amounts reclassified from accumulated other comprehensive loss	109	308
Net current period other comprehensive income	1,689	3,094
Balance at ending	$ (4,574)	$ (6,263)