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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Numerator for basic and diluted earnings (loss) per share:
Net income (loss)	$ 25,880	$ 3,966	$ 4,487	$ (16,905)
Denominator:
Basic shares outstanding (in shares)	57,190	57,549	57,226	57,599
Dilutive effect of equity-based compensation awards (in shares)	146	129	123	0
Dilutive shares outstanding (in shares)	57,336	57,678	57,349	57,599
Basic loss per share (in USD per share)	$ 0.45	$ 0.07	$ 0.08	$ (0.29)
Diluted loss per share (in USD per share)	$ 0.45	$ 0.07	$ 0.08	$ (0.29)