Stockholders' Equity - Summary of Stock Option Activity and Weighted Average Exercise Prices (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	9 Months Ended
	Mar. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Options
Beginning balance (in shares)	4,332	4,332
Granted (in shares)		751
Exercised (in shares)		(652)
Cancelled or expired (in shares)		(138)
Ending balance (in shares)		4,293
Options vested and expected to vest (in shares)		1,273
Options exercisable at end of period (in shares)		2,372
Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 19.78	$ 19.78
Granted (in dollars per share)
Exercised (in dollars per share)
Cancelled or expired (in dollars per share)
Ending balance (in dollars per share)		26.97
Options vested and expected to vest (in dollars per share)		36.57
Options exercisable at end of period (in dollars per share)		$ 16.97
Weighted Average Remaining Contractual Term (In years)
Weighted average remaining contract term, Options outstanding	6 years 9 months 14 days	6 years 10 months 20 days
Weighted average remaining contract term, Options vested and expected to vest		8 years 3 months 18 days
Weighted average remaining contract term, Options exercisable		5 years 6 months 21 days
Aggregate Intrinsic Value
Aggregate intrinsic value, Options outstanding		$ 139,007	$ 183,825
Aggregate intrinsic value, Options vested and expected to vest		29,454
Aggregate intrinsic value, Options exercisable		$ 99,585