Stockholders' Equity and Employee Benefit Plans - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Shares
Outstanding, vested and expected to vest, Beginning balance	18,452,375	13,809,069	12,028,622
Granted	3,394,030	5,735,643	4,139,372
Exercised	(3,733,401)	(81,849)	(35,352)
Forfeited	(1,351,967)	(832,591)	(1,623,057)
Expired	(948,109)	(177,897)	(700,516)
Outstanding, vested and expected to vest, Ending balance	15,812,928	18,452,375	13,809,069	12,028,622
Vested and exercisable at December 31, 2019	9,976,540
Weighted Average Exercise Price
Outstanding, vested and expected to vest, Beginning balance	$ 14.39	$ 14.82	$ 14.53
Granted	14.17	13.31	16.03
Exercised	12.77	6.01	4.35
Forfeited	14.02	15.01	16.02
Expired	15.84	14.08	14.77
Outstanding, vested and expected to vest, Ending balance	14.67	$ 14.39	$ 14.82	$ 14.53
Vested and exercisable at December 31, 2019	$ 14.86
Additional Disclosures
Outstanding, vested and expected to vest, Aggregate Intrinsic Value, Beginning balance	$ 50,994	$ 8,482	$ 9,292	$ 9,903
Vested and exercisable at December 31, 2019	$ 30,028
Outstanding, vested and expected to vest, Weighted Average Remaining Contractual Term	7 years 4 months 24 days	7 years 6 months	7 years 9 months 18 days	8 years 3 months 18 days
Vested and exercisable, Weighted Average Remaining Contractual Term	6 years 7 months 6 days