LONG TERM DEBT (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Long-Term Debt
Total debt before unamortized discount and debt issuance costs	$ 521,695	$ 460,956
Unamortized discount and debt issuance costs, net	(9,702)	(10,692)
Total debt	511,993	450,264
Current portion of long-term debt	9,027	4,336
Long-term debt	502,966	445,928
Revolving Credit Facility | Prior Credit Agreement, dated June 17, 2013
Long-Term Debt
Total debt before unamortized discount and debt issuance costs		5,000
Term Loan B | Credit Agreement, dated March 6, 2018
Long-Term Debt
Total debt before unamortized discount and debt issuance costs	502,475
Term Loan B | Prior Credit Agreement, dated August 1, 2016
Long-Term Debt
Total debt before unamortized discount and debt issuance costs		280,000
Term Loan | Prior Credit Agreement, dated June 17, 2013
Long-Term Debt
Total debt before unamortized discount and debt issuance costs		151,875
Seller notes
Long-Term Debt
Total debt before unamortized discount and debt issuance costs	3,796	5,912
Financing leases and other
Long-Term Debt
Total debt before unamortized discount and debt issuance costs	$ 15,424	$ 18,169