DEBT - Summary of Total Debt Outstanding (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Sep. 17, 2019	Dec. 31, 2018
Long-term debt:
Total long-term debt	$ 705,000		$ 661,082
Senior Notes	300,000		0
Less: Convertible Notes discount and deferred financing costs, net	(23,260)		(30,125)
Less: Current maturities of long-term debt	(5,000)		(8,750)
Less: Term Loan deferred financing costs, net	(542)		(456)
Total long-term debt, less current maturities, net	670,354		621,751
2015 Revolver
Long-term debt:
Total long-term debt	135,000		392,332
Term Loan
Long-term debt:
Total long-term debt	97,500		96,250
Convertible Debt
Long-term debt:
Total long-term debt	172,500		172,500
7.50% Senior Notes Due 2027 | Senior Notes
Long-term debt:
Less: Senior Notes deferred financing costs, net	$ (5,844)	$ (6,000)	$ 0