NET INCOME (LOSS) PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share
Net income (loss)	$ (4,491)	$ 4,208	$ 8,353	$ 12,985	$ (14,988)	$ 2,633	$ (14,116)	$ 6,021	$ (212,775)	$ (13,033)	$ (104,022)	$ 17,887	$ 21,055	$ (20,450)	$ (311,943)
Weighted average number of common shares	299,518	298,510	298,237	298,242	300,107	300,530	300,530	297,255	299,009	297,164	297,164	297,159	298,772	300,341	297,763
Effect of employee stock-based awards													1,701
Diluted shares outstanding	301,102	301,045	299,791	298,554	300,107	300,530	300,530	297,266	299,009	297,164	297,164	298,410	300,474	300,341	297,763
Net income (loss) per share:
Net income (loss) per share	$ (0.01)	$ 0.01	$ 0.03	$ 0.04	$ (0.05)	$ 0.01	$ (0.05)	$ 0.02	$ (0.71)	$ (0.04)	$ (0.35)	$ 0.06	$ 0.07	$ (0.07)	$ (1.05)
Diluted (in dollars per share)	$ (0.01)	$ 0.01	$ 0.03	$ 0.04	$ (0.05)	$ 0.01	$ (0.05)	$ 0.02	$ (0.71)	$ (0.04)	$ (0.35)	$ 0.06	$ 0.07	$ (0.07)	$ (1.05)
Options
Antidilutive Securities Excluded from Computation of Earnings Per Share
Options outstanding not included in the computation of diluted weighted average shares because their effect would have been anti-dilutive (in shares)													2,000
Average exercise price of options outstanding (in dollars per share)													$ 3.91