EARNINGS PER SHARE - (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
EARNINGS PER SHARE
Net loss available for stockholders :	$ (726)	$ (9,662)	$ (25,093)	$ (160,423)	$ (10,388)	$ (185,516)
Less: Adjustments for earnings attributable to participating securities	0		0		0	0
Net loss used in calculating earnings per share	$ (726)		$ (25,093)		$ (10,388)	$ (185,516)
Weighted average shares outstanding (including participating securities)	215,728		215,174		215,633	215,090
Adjustment for participating securities	(2,719)		(2,772)		(2,663)	(2,730)
Shares used in calculating basic and diluted earnings per share	213,009		212,402		212,970	212,360