LOSS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	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, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share
Net income (loss)	$ (14,988)	$ 2,633	$ (14,116)	$ 6,021	$ (212,775)	$ (13,033)	$ (104,022)	$ 17,887	$ (11,343)	$ 3,264	$ (128,681)	$ (10,982)	$ (20,450)	$ (311,943)	$ (147,742)
Weighted average number of common shares	300,107,000	300,530,000	300,530,000	297,255,000	299,009	297,164	297,164	297,159	297,159	297,125	297,097	296,778	300,341,000	297,763,000	297,041,000
Net income (loss) per share	$ (0.05)	$ 0.01	$ (0.05)	$ 0.02	$ (0.71)	$ (0.04)	$ (0.35)	$ 0.06	$ (0.04)	$ 0.01	$ (0.43)	$ (0.04)	$ (0.07)	$ (1.05)	$ (0.50)
Weighted average common shares outstanding (thousands) (note 12):
Diluted (in shares)	300,107,000	300,530,000	300,530,000	297,266,000	299,009	297,164	297,164	298,410	297,159	297,899	297,097	296,778
Net income (loss) per share:
Diluted (in dollars per share)	$ (0.05)	$ 0.01	$ (0.05)	$ 0.02	$ (0.71)	$ (0.04)	$ (0.35)	$ 0.06	$ (0.04)	$ 0.01	$ (0.43)	$ (0.04)	$ (0.07)	$ (1.05)	$ (0.50)
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)													6,900,000	3,300,000	2,100,000
Average exercise price of options outstanding (in dollars per share)													$ 2.49	$ 3.95	$ 5.04
Other 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)													100,000	1,800,000	3,600,000