(LOSS) / INCOME PER COMMON SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Numerator:
Net (loss) / income	$ (35,203)	$ 26,864
Denominator:
Weighted-average shares outstanding, basic	83,267	82,960
Basic net (loss) / income per share (in dollars per share)	$ (0.42)	$ 0.32
Numerator:
Net (loss) / income	$ (35,203)	$ 26,864
Denominator:
Weighted-average shares outstanding, basic	83,267	82,960
Add:
Weighted-average shares outstanding, diluted	83,267	82,991
Diluted net (loss) / income per share (in dollars per share):	$ (0.42)	$ 0.32
Stock options
Add:
Incremental common shares attributable to share-based payment arrangements		31,000