Stock-Based Compensation - Stock Option Activity (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares shares
Number of Option Shares
Options outstanding (in shares) | shares	7,817,436
Granted (in shares) | shares	652,733
Exercised (in shares) | shares	(4,362,654)
Forfeited (in shares) | shares	(508,326)
Options outstanding (in shares) | shares	3,599,189
Options outstanding, weighted average remaining contractual term	6 years 5 months 15 days
Options outstanding, aggregate intrinsic value | $	$ 242.2
Weighted-Average Exercise Price
Options outstanding (in dollars per share) | $ / shares	$ 16.30
Granted (in dollars per share) | $ / shares	26.79
Exercised (in dollars per share) | $ / shares	14.37
Forfeited (in dollars per share) | $ / shares	21.69
Options outstanding (in dollars per share) | $ / shares	$ 19.79
Options Exercisable
Options exercisable (in shares) | shares	1,343,421
Options exercisable, weighted average exercise price (in dollars per share) | $ / shares	$ 16.71
Options exercisable, weighted average remaining contractual term	3 years 11 months 8 days
Options exercisable, aggregate intrinsic value | $	$ 94.6