INCOME (LOSS) PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share
Net income (loss)	$ 8,353	$ (14,116)	$ 21,338	$ (8,095)
Weighted average number of common shares	298,237	300,530	298,239	300,364
Weighted average common shares outstanding (thousands) (note 11):
Effect of employee stock-based awards (in shares)	1,554		992
Diluted (in shares)	299,791	300,530	299,231	300,364
Net income (loss) per share:
Net income (loss) per share	$ 0.03	$ (0.05)	$ 0.07	$ (0.03)
Diluted (in dollars per share)	$ 0.03	$ (0.05)	$ 0.07	$ (0.03)
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)	2,300	4,400	3,000	4,400
Average exercise price of options outstanding (in dollars per share)	$ 4.20	$ 3.36	$ 3.73	$ 3.49