Stock Incentive Plans - Summary of Stock Option Activity Plans, Including Grants To Nonemployees (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Options Outstanding
Beginning balance (in shares)	1,503,247	2,094,137	2,601,181
Options granted (in shares)	0	20,010	366,928
Options exercised (in shares)	(868,614)	(540,307)	(798,424)
Options forfeited (in shares)	(24,752)	(70,593)	(75,548)
Ending balance (in shares)	609,881	1,503,247	2,094,137	2,601,181
Options exercisable (in shares)	486,423
Options vested and expected to vest (in shares)	606,418
Weighted- Average Exercise Price Per Share
Beginning balance (in USD per share)	$ 27.40	$ 23.20	$ 12.24
Options granted (in USD per share)	0	82.77	68.32
Options exercised (in USD per share)	17.31	9.59	7.19
Options forfeited (in USD per share)	66.89	54.54	34.30
Ending balance (in USD per share)	40.18	$ 27.40	$ 23.20	$ 12.24
Options exercisable (in USD per share)	34.36
Options vested and expected to vest (in USD per share)	$ 40.01
Weighted- Average Remaining Contractual Life (years)
Weighted-average remaining contractual life for options outstanding (in years)	6 years 2 months 26 days	6 years 5 months 4 days	7 years 7 days	7 years 2 months 1 day
Weighted-average remaining contractual life for options exercisable (in years)	6 years 7 days
Weighted-average remaining contractual life for options vested and expected to vest (in years)	6 years 2 months 26 days
Aggregate Intrinsic Value (in thousands)
Aggregate intrinsic value of options outstanding	$ 120,163	$ 62,401	$ 97,976	$ 113,958
Aggregate intrinsic value of options exercisable	98,672
Aggregate intrinsic value of options vested and expected to vest	$ 119,583