SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Feb. 28, 2014
Debt Instrument [Line Items]
Net loss from continuing operations	$ (199,928)	$ (23,617)	$ (120,827)	$ (122,084)	$ (20,746)	$ (64,678)	$ (25,817)	$ (58,098)	$ (466,456)	$ (169,339)	$ (205,153)
Net income from discontinued operations	$ 0	$ 0	$ 0	$ 0	$ (1,531)	$ 95,517	$ 5,736	$ 3,856	$ 0	$ 103,578	$ 5,925
Weighted average common shares outstanding (in shares)									34,030	34,394	34,907
Effect of dilutive securities:
Stock options and RSUs (in shares)									0	0	0
Shares used in calculating dilutive net loss per share (in shares)									34,030	34,394	34,907
Basic and diluted earnings per share:
Loss from continuing operations (in dollars per share)	$ (5.89)	$ (0.70)	$ (3.57)	$ (3.54)	$ (0.60)	$ (1.88)	$ (0.75)	$ (1.70)	$ (13.71)	$ (4.92)	$ (5.88)
Income from discontinued operations (in dollars per share)	0	0	0	0	(0.04)	2.77	0.17	0.11	0	3.01	0.17
Total (in dollars per share)	$ (5.89)	$ (0.70)	$ (3.57)	$ (3.54)	$ (0.64)	$ 0.89	$ (0.58)	$ (1.59)	$ (13.71)	$ (1.91)	$ (5.71)
Convertible Debt | Convertible Notes Due 2019
Debt Instrument [Line Items]
Interest rate													2.50%
Convertible Debt | 2022 Convertible Notes
Debt Instrument [Line Items]
Interest rate	3.25%								3.25%			3.25%