Stock Option Plans - Narrative (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units grants (in shares)		8,546,205
Share based compensation expense	$ 6,800,000	$ 14,600,000
Total unrecognized compensation cost	73,900,000	$ 73,900,000
Recognized average period		2 years 11 months 19 days
Total grant date fair value of shares vested		$ 23,700,000
Issued outstanding performance-based awards (in shares)			150,000
Awards issued (in shares)		9,848,048
PSUs term		5 years
Expense from PSUs	1,600,000	$ 1,600,000
Expected dividend yield		0.00%	0.00%
Weighted-average grant date fair value per share of stock options granted (in dollars per share)		$ 7.69
Unrecognized stock-based compensation cost	2,200,000	$ 2,200,000
Stock Plan 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units granted (in shares)		9,848,048
Restricted stock units vested (in shares)		1,301,843
Recognized average period		2 years 3 months 10 days
Performance Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost	$ 0	$ 0
Stock-based compensation expense		$ 2,500,000
Awards issued (in shares)		2,761,087
Vesting threshold trading days		20 days
Trading window		30 days
Stock Plan 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance (in shares)	38,018,247	38,018,247
Vesting period		4 years
Expected dividend yield		0.00%