SEGMENT INFORMATION - Operating Income (loss) and Adjusted EBITDA by Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Operating (loss) income	$ 17,885	$ 33,515	$ 23,262	$ (10,756)	$ (33,918)	$ (112,505)	$ (2,836)	$ 1,388	$ 63,906	$ (147,871)	$ 24,058
North America
Segment Reporting Information [Line Items]
Operating (loss) income									78,102	(128,483)	32,464
Adjusted EBITDA									253,963	50,182	50,088
Europe
Segment Reporting Information [Line Items]
Operating (loss) income									(14,196)	(19,388)	(8,406)
Adjusted EBITDA									$ (6,457)	$ (11,019)	$ (5,542)