Employee Benefit Plans - Stock Activity, Weighted Average Exercise Price (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Shares
Granted (in shares)			698,500	174,649
Stock options
Shares
Options outstanding, beginning balance (in shares)			10,284,498
Granted (in shares)			698,500
Exercised (in shares)			(1,812,099)
Forfeited (in shares)			(5,833)
Options outstanding, end balance (in shares)	9,165,066		9,165,066		10,284,498
Options exercisable (in shares)	2,523,341		2,523,341
Options unvested (in shares)	6,641,725		6,641,725
Weighted Average Exercise Price
Options outstanding, beginning balance, weighted-average exercise price			$ 5.78
Granted, weighted-average exercise price			46.82
Exercised, weighted-average exercise price			2.65
Forfeited, weighted-average exercise price			6.78
Options outstanding, end balance, weighted-average exercise price	$ 9.51		9.51		$ 5.78
Options exercisable, weighted-average exercise price	2.17		2.17
Options unvested, weighted-average exercise price	$ 12.30		$ 12.30
Stock option activity additional disclosures
Options outstanding, weighted-average remaining contractual term			7 years 10 months 24 days		7 years 9 months 18 days
Options exercisable, weighted-average remaining contractual term			5 years 7 months 6 days
Options unvested, weighted-average remaining contractual term			8 years 8 months 12 days
Options outstanding, aggregate intrinsic value	$ 226,164		$ 226,164		$ 289,316
Options exercisable, aggregate intrinsic value	80,808		80,808
Options unvested, aggregate intrinsic value	$ 145,356		$ 145,356
Weighted-average grant date fair value of options granted (per share)	$ 29.23	$ 4.88	$ 46.67	$ 7.73
Unrecognized compensation cost	$ 38,300		$ 38,300
Period for recognition			3 years
Fair value of stock options that vested during the period	$ 432,000	$ 493,000	$ 520,000	$ 516,000