Net (Loss) Income Per Share - Calculation of Net (Loss) Income and Number of Shares Used to Compute Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net (loss) income	$ (27,827)	$ (55,451)	$ 28,234	$ (171,285)
Shares used in basic computation (in shares)	193,225	188,921	191,677	188,456
Dilutive impact of employee equity award plans (in shares)	0	0	2,874	0
Dilutive impact of convertible debt (in shares)	0	0	528	0
Shares used in diluted computation (in shares)	193,225	188,921	195,079	188,456
Basic (in usd per share)	$ (0.14)	$ (0.29)	$ 0.15	$ (0.91)
Diluted (in usd per share)	$ (0.14)	$ (0.29)	$ 0.14	$ (0.91)