EARNINGS (LOSS) PER SHARE (Computation of Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Numerator for basic and diluted earnings (loss) per share:
Net income (loss)	$ 12,058	$ (10,255)	$ 16,545	$ (27,160)
Denominator:
Basic shares outstanding (in shares)	57,033	57,487	57,149	57,575
Dilutive effect of equity-based compensation awards (in shares)	162	0	131	0
Dilutive shares outstanding (in shares)	57,195	57,487	57,280	57,575
Basic loss per share (in USD per share)	$ 0.21	$ (0.18)	$ 0.29	$ (0.47)
Diluted loss per share (in USD per share)	$ 0.21	$ (0.18)	$ 0.29	$ (0.47)