OTHER - Components of Accumulated Other Comprehensive Loss, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021	Sep. 30, 2021	Sep. 30, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of year	$ 241,801	$ 194,871	$ 230,136	$ 230,136	$ 236,317
Balance at end of year	255,975	211,793	241,801	255,975	211,793
Accumulated translation adjustment:
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of year	(31,623)	(40,991)	(35,846)	(35,846)	(34,019)
Other comprehensive income, before reclassifications	(1,122)	2,145		1,059	(5,062)
Amounts reclassified from accumulated other comprehensive loss	1,362	0		3,404	235
Other comprehensive income (loss), net of taxes	240	2,145		4,463	(4,827)
Balance at end of year	(31,383)	(38,846)	(31,623)	(31,383)	(38,846)
Accumulated deferred losses on cash flow hedges:
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of year	(1,062)	(1,612)	(1,125)	(1,125)	1,164
Other comprehensive income, before reclassifications	528	(89)		(255)	(3,224)
Amounts reclassified from accumulated other comprehensive loss	464	305		1,310	664
Other comprehensive income (loss), net of taxes	992	216		1,055	(2,560)
Balance at end of year	(70)	(1,396)	(1,062)	(70)	(1,396)
Income tax expense (benefit)	(247)	(73)		(301)	856
Accumulated effect of retirement benefit obligations:
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of year	(2,133)	(1,561)	(2,201)	(2,201)	(1,600)
Amounts reclassified from accumulated other comprehensive loss	33	20		101	59
Balance at end of year	(2,100)	(1,541)	(2,133)	(2,100)	(1,541)
Accumulated other comprehensive  loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of year	(34,818)	(44,164)	(39,172)	(39,172)	(34,455)
Balance at end of year	$ (33,553)	$ (41,783)	$ (34,818)	$ (33,553)	$ (41,783)