Stock-based Awards - Schedule of Restricted Stock Units Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Number of Shares
Non-vested at the end of the period (in dollars per share)	4,339,320
Weighted-Average Grant Date Fair Value
Total stock-based compensation expense	$ 24,739	$ 42,563	$ 29,333
Restricted Stock Units (RSUs)
Stock-based Awards
Fair value of shares of restricted stock awards vested	$ 11,800	$ 6,500	$ 300
Number of Shares
Non-vested at the beginning of period (in shares)	3,747,340
Granted (in shares)	2,711,392
Vested (in shares)	(1,370,672)
Canceled/forfeited (in shares)	(748,740)
Non-vested at the end of the period (in dollars per share)	4,339,320	3,747,340
Weighted-Average Grant Date Fair Value
Non-vested at the beginning of period (in dollars per share)	$ 8.18
Granted (in dollars per share)	7.37	$ 8.17	$ 12.35
Vested (in dollars per share)	8.06
Canceled/forfeited (in dollars per share)	7.38
Non-vested at the end of the period (in dollars per share)	$ 7.85	$ 8.18
Total stock-based compensation expense	$ 9,900	$ 8,600	$ 2,000