EARNING (LOSS) PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ 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, 2015	Dec. 31, 2014	Dec. 31, 2013
Numerator for basic and diluted earnings (loss) per share:
Net income (loss)	$ 568	$ 40,228	$ 10,395	$ (7,089)	$ 27,377	$ (93,337)	$ 28,672	$ 8,960	$ 44,102	$ (28,328)	$ 95,566
Denominator:
Weighted basic shares outstanding									58,324	60,311	60,574
Dilutive effect of equity-based compensation awards									110	0	154
Weighted dilutive shares outstanding									58,434	60,311	60,728
Basic earnings per share:
Basic earnings per share (in dollars per share)									$ 0.76	$ (0.47)	$ 1.58
Diluted earnings per share:
Diluted earnings per share (in dollars per share)									$ 0.76	$ (0.47)	$ 1.57