(Loss) Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Net (loss) income	$ (28,747)	$ 41,027
Net (loss) income per share:
Basic (in Dollars per share)	$ (0.23)	$ 0.33
Diluted (in Dollars per share)	$ (0.23)	$ 0.33
Shares used in computing net (loss) income per share:
Weighted average basic shares outstanding (in Shares)	125,240	124,421
Dilutive securities:
Stock option and unvested RSUs (in Shares)	0	245
Total dilutive securities (in Shares)		245
Weighted average diluted shares outstanding (in Shares)	125,240	124,666
Shares subject to stock options omitted from the calculation of (loss) income per share as their effect would have been anti-dilutive (in Shares)	3,356	4,093