EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Numerator:
Net income	$ (60,466)	$ 45,689	$ 78,786	$ 179,474
Denominator:
Basic weighted average shares outstanding (in shares)	73,754,000	78,817,000	74,999,000	79,779,000
Effect of dilutive securities - Stock options and awards (in shares)	0	908,000	765,000	923,000
Diluted weighted average shares outstanding (in shares)	73,754,000	79,725,000	75,764,000	80,702,000
Earnings (loss) per share
Basic earnings (loss) per share (in dollars per share)	$ (0.82)	$ 0.58	$ 1.05	$ 2.25
Diluted earnings (loss) per share (in dollars per share)	$ (0.82)	$ 0.57	$ 1.04	$ 2.22
Anti-dilutive shares excluded from the computation of diluted earnings per share	1,279,664	259,336	508,070	260,964