Stock-Based Compensation - Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Options (in shares):
Outstanding beginning of the period (in shares)	6,400,175
Granted (in shares)	0	0
Forfeited (in shares)	(50,437)
Exercised (in shares)	(1,996,571)
Outstanding end of the period (in shares)	4,353,167	6,400,175
Exercisable at end of the period (in shares)	3,723,394
Weighted-Average Exercise Price (in dollars per share):
Outstanding beginning of the period (in dollars per share)	$ 13.65
Granted (in dollars per share)	0
Forfeited (in dollars per share)	17.32
Exercised (in dollars per share)	12.10
Outstanding end of the period (in dollars per share)	14.32	$ 13.65
Exercisable at the end of the period (in dollars per share)	$ 13.89
Outstanding, weighted-average remaining contractual term (years)	5 years 7 months 6 days	6 years 1 month 6 days
Exercisable, weighted-average remaining contractual term (years)	5 years 3 months 18 days
Outstanding, aggregate intrinsic value	$ 120,714	$ 142,340
Exercisable, aggregate intrinsic value	104,868
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Options exercised intrinsic value	75,600	27,500	$ 9,800
Options grants in period, weighted average grant date fair value (in dollars per share)			$ 6.79
Options vested in period fair value	5,800	$ 12,400	$ 10,200
Options unrecognized compensation expense	$ 3,400
Employee stock options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Options unrecognized compensation expense, period for recognition (years)	1 year 4 months 24 days
Class A Common Stock | Employee stock options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Expiration period (years)	10 years
Minimum | Class A Common Stock | Employee stock options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Award vesting period (years)	3 years
Maximum | Class A Common Stock | Employee stock options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Award vesting period (years)	4 years