Stock-based Awards - Schedule of Restricted Stock Units Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Number of Shares
Non-vested at the end of the period (in dollars per share)	5,890,992
Weighted-Average Grant Date Fair Value
Total stock-based compensation expense	$ 37,974	$ 37,219	$ 32,241
Restricted Stock Units (RSUs)
Stock-based Awards
Fair value of shares of restricted stock awards vested	$ 16,000	$ 22,400	$ 25,600
Number of Shares
Non-vested at the beginning of period (in shares)	5,375,963
Granted (in shares)	5,436,368
Vested (in shares)	(2,830,183)
Canceled/forfeited (in shares)	(2,091,156)
Non-vested at the end of the period (in dollars per share)	5,890,992	5,375,963
Weighted-Average Grant Date Fair Value
Non-vested at the beginning of period (in dollars per share)	$ 11.01
Granted (in dollars per share)	6.36	$ 10.00	$ 18.26
Vested (in dollars per share)	9.44
Canceled/forfeited (in dollars per share)	9.63
Non-vested at the end of the period (in dollars per share)	$ 7.96	$ 11.01
Total stock-based compensation expense	$ 24,300	$ 21,200	$ 14,900