NET INCOME (LOSS) PER SHARE (Basic and Diluted Net Income Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basic net income (loss) per share:
Net income from continuing operations									$ 64,743	$ 74,564	$ 6,851
Net loss from discontinued operations									0	0	(10,370)
Net income (loss)	$ 44,355	$ 3,159	$ 10,835	$ 6,394	$ 28,246	$ 20,144	$ 12,755	$ 13,419	$ 64,743	$ 74,564	$ (3,519)
Weighted average common shares outstanding, basic (in shares)									76,897	74,386	68,990
Basic net income per common share from continuing operations (in dollars per share)									$ 0.84	$ 1.00	$ 0.10
Loss from discontinued operations (in dollars per share)									0.00	0.00	(0.15)
Net income (loss) per share - basic (in dollars per share)	$ 0.57	$ 0.04	$ 0.14	$ 0.09	$ 0.38	$ 0.27	$ 0.17	$ 0.18	$ 0.84	$ 1.00	$ (0.05)
Diluted net income (loss) per share:
Net income from continuing operations									$ 64,743	$ 74,564	$ 6,851
Net loss from discontinued operations									0	0	(10,370)
Net income (loss)	$ 44,355	$ 3,159	$ 10,835	$ 6,394	$ 28,246	$ 20,144	$ 12,755	$ 13,419	$ 64,743	$ 74,564	$ (3,519)
Weighted average common shares outstanding, basic (in shares)									76,897	74,386	68,990
Effect of dilutive securities:
2016 Convertible notes (in shares)									0	2,296	922
Warrants (in shares)									971	1,166	0
Stock options and restricted stock (in shares)									1,253	1,346	1,442
Weighted average common shares for diluted earnings per share (in shares)									79,121	79,194	71,354
Diluted net income per common share from continuing operations (in dollars per share)									$ 0.82	$ 0.94	$ 0.10
Diluted net loss per common share from discontinued operations (in dollars per share)									0.00	0.00	(0.15)
Net income (loss) per share - diluted (in dollars per share)	$ 0.56	$ 0.04	$ 0.14	$ 0.08	$ 0.35	$ 0.25	$ 0.16	$ 0.18	$ 0.82	$ 0.94	$ (0.05)