SEGMENT REPORTING - Reconciliation of Operating Income to Consolidated Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Adjustment for:
Amortization of intangible assets			$ 12,575	$ 12,943
Income from operations	$ 16,813	$ 6,510	48,022	25,003
Interest expense	4,781	4,928	15,959	12,573
Other expense (income), net	120	(153)	(1,318)	(324)
Income before income taxes	11,912	1,735	33,381	12,754
Operating Segments
Segment Reporting Information, Operating Income (Loss) [Abstract]
Operating income for reportable segments	33,249	21,370	94,658	66,169
Segment Reconciling Items
Adjustment for:
Amortization of intangible assets	4,098	4,336	12,575	12,943
Corporate, Non-Segment
Adjustment for:
Corporate expenses	$ 12,338	$ 10,524	$ 34,061	$ 28,223