Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Numerator:
Net loss	$ (58,993)	$ (78,909)
Basic net income (loss) allocable to common shareholders	(58,993)	(78,909)
Diluted net income (loss) allocable to common shareholders	$ (58,993)	$ (78,909)
Weighted average number of shares used to compute net income (loss) per share:
Basic (in shares)	384,435	380,355
Diluted (in shares)	384,435	380,355
Net income (loss) per share:
Basic (in dollars per share)	$ (0.15)	$ (0.21)
Diluted (in dollars per share)	$ (0.15)	$ (0.21)
Outstanding restricted stock awards and units excluded from the computations of diluted net income per share (in shares)	13,600	18,100