ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Changes in AOCI (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($)
Accumulated other comprehensive income (loss)
Balance at the beginning	$ 324,077
Balance at the end	353,841
Foreign Currency Translation
Accumulated other comprehensive income (loss)
Balance at the beginning	(8,603)
Other comprehensive income before reclassifications, net of tax	(1,878)
Other comprehensive income, net	(1,878)
Balance at the end	(10,481)
Unrealized Gain (Loss) on Interest Rate Hedge
Accumulated other comprehensive income (loss)
Balance at the beginning	(501)
Other comprehensive income before reclassifications, net of tax	2,310
Amounts reclassified out of AOCI, net of tax	341
Other comprehensive income, net	2,651
Balance at the end	2,150
Accumulated Other Comprehensive Income (Loss)
Accumulated other comprehensive income (loss)
Balance at the beginning	(9,104)
Other comprehensive income before reclassifications, net of tax	432
Amounts reclassified out of AOCI, net of tax	341
Other comprehensive income, net	773
Balance at the end	$ (8,331)