EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Numerator:
Net income (loss)	$ 55,844	$ 53,638
Denominator (shares in 000's):
Basic weighted average shares outstanding (in shares)	65,688,000	69,585,000
Effect of dilutive securities - Stock options and awards (in shares)	895,000	661,000
Diluted weighted average shares outstanding (in shares)	66,583,000	70,246,000
Earnings (loss) per share
Basic earnings (loss) per share (in dollars per share)	$ 0.85	$ 0.77
Diluted earnings (loss) per share (in dollars per share)	$ 0.84	$ 0.76
Anti-dilutive shares excluded from the computation of diluted earnings per share	88,220	776,600