COMMON STOCK AND SHARE-BASED COMPENSATION (Restricted Stock Units) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Restricted Stock Units
Nonvested, beginning balance (in shares)	1,040,835
Granted (in shares)	1,007,782
Vested (in shares)	(944,090)
Forfeited (in shares)	(214,174)
Nonvested, ending balance (in shares)	890,353	1,040,835
Weighted Average Grant- Date Fair Value
Nonvested, beginning balance (in dollars per share)	$ 44.06
Granted (in dollars per share)	9.25	$ 18.57	$ 40.92
Vested (in dollars per share)	33.14
Forfeited (in dollars per share)	15.75
Nonvested, ending balance (in dollars per share)	$ 23.05	$ 44.06