Net (Loss)/Income Per Share - Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share, Basic and Diluted [Abstract]
Net (loss)/income	$ (17,214)	$ (43,727)	$ (17,949)	$ (8,550)	$ (2,958)	$ 158	$ (5,509)	$ 1,124	$ (87,440)	$ (7,185)	$ 8,148
Basic and diluted shares used to compute net (loss)/income per share:
Weighted average common shares outstanding									132,808	122,414	93,575
Weighted average common shares subject to restrictions									(1,004)	(3,639)	(1,749)
Weighted average shares used to compute basic net (loss)/income per share									131,804	118,775	91,826
Dilutive potential common shares											5,096
Weighted average shares used to compute diluted net (loss)/income per share									131,804	118,775	96,922
Basic net (loss)/income per share	$ (0.13)	$ (0.33)	$ (0.14)	$ (0.07)	$ (0.02)	$ 0.00	$ (0.05)	$ 0.01	$ (0.66)	$ (0.06)	$ 0.09
Diluted net (loss)/income per share	$ (0.13)	$ (0.33)	$ (0.14)	$ (0.07)	$ (0.02)	$ 0.00	$ (0.05)	$ 0.01	$ (0.66)	$ (0.06)	$ 0.08