DEBT (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Credit and Security Agreement [Abstract]
Term loan, amount outstanding	$ 113,600		$ 114,200
Deferred finance cost net	1,700		$ 1,800
Borrowings under revolving credit line	10,000	$ 0
Repayments of revolving credit line	$ (10,000)	0
KeyBank [Member]
Credit and Security Agreement [Abstract]
Line of credit facility, maturity date	Dec. 11, 2022
Weighted average interest rate	4.25%		4.31%
Interest expense incurred	$ 1,400	$ 1,200
KeyBank [Member] | Term Loan [Member]
Credit and Security Agreement [Abstract]
Term loan, amount outstanding	115,200		$ 116,000
KeyBank [Member] | Revolving Credit Facility [Member]
Credit and Security Agreement [Abstract]
Line of credit, amount outstanding	0		0
Unused borrowing capacity	75,000		$ 75,000
Borrowings under revolving credit line	10,000
Repayments of revolving credit line	$ (10,000)