EARNINGS PER SHARE - (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
EARNINGS PER SHARE
Net loss available for stockholders:	$ (16,437)	$ (25,093)	$ (160,423)	$ (69,181)	$ 6,171	$ (739)	$ (201,953)	$ (63,749)
Less: Adjustments for earnings attributable to participating securities	0			0			0	(334)
Net loss used in calculating earnings per share	$ (16,437)			$ (69,181)			$ (201,953)	$ (64,083)
Weighted average shares outstanding (including participating securities)	215,083			214,521			215,088	214,823
Adjustment for participating securities	(2,539)			(2,496)			(2,697)	(2,538)
Shares used in calculating basic and diluted earnings per share	212,544			212,025			212,391	212,285