ACCUMULATED OTHER COMPREHENSIVE INCOME - Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net foreign currency translation adjustment	$ (11,255)	$ 12,829	$ (891)
Unrealized gain/(loss) on cash flow hedge	2,707	(3,094)	(1,771)
Tax	(654)	809	372
Net of tax	2,053	(2,285)	(1,399)
Net change in postretirement benefit plan (see Note 15 for further information)
Prior service (credit)/cost and (gain)/loss arising during the period	(4)	(503)	199
Amortization of prior service credit/(cost)	74	74	74
Amortization of gain/(loss)	(21)	(50)	(46)
Total before tax	49	(479)	227
Tax	(13)	127	101
Adjustment	0	(455)	0
Net of tax	36	(807)	328
Total other comprehensive (loss)/income	(9,166)	9,737	(1,962)
Net investment hedge
Net change in postretirement benefit plan (see Note 15 for further information)
Net foreign currency translation adjustment tax	1,527	1,579	70
Net investment hedge | Currency swap
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net foreign currency translation adjustment	$ 4,766	$ (4,882)	$ (262)