Stock Based Compensation - Narrative (Details) $ in Thousands	1 Months Ended			3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021 USD ($) multiplier shares	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2021 USD ($) multiplier	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) multiplier shares	Sep. 30, 2020 USD ($)	Dec. 31, 2020 shares	Dec. 15, 2020 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of stock outstanding			5.00%
Unrecognized stock-based compensation expense	$ 233,700			$ 233,700		$ 233,700
Unrecognized stock-based compensation expense, period for recognition						3 years 6 months 7 days
Total stock-based compensation expense				15,812	$ 3,662	$ 42,531	$ 9,565
Aggregate intrinsic value				47,800	$ 20,400	59,600	$ 47,800
Chief Financial Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental stock-based compensation expense				6,400
Total stock-based compensation expense				2,700		$ 6,400
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued (in shares) | shares						9,100,000		13,300,000
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued (in shares) | shares						200,000
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense				100		$ 200
Purchase price of common stock, percentage of fair market value		85.00%
2020 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period			10 years
Vesting period			1 year
Shares authorized (in shares) | shares									47,841,859
2020 Omnibus Incentive Plan | Common Class A and B
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized (in shares) | shares									15,000,000
2020 Omnibus Incentive Plan | Class A common stock, par value $0.0001 per share
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized (in shares) | shares									24,669,278
2020 Omnibus Incentive Plan | Class B Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized (in shares) | shares									8,172,581
2020 Omnibus Incentive Plan | Performance stock units | Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period						7 years
Shares granted (in shares) | shares	16,100,000
Unrecognized stock-based compensation expense	$ 70,000			70,000		$ 70,000
Unrecognized stock-based compensation expense, period for recognition						4 years 1 month 20 days
Total stock-based compensation expense				$ 800		$ 800
Trading days	30 days
Market capitalization milestone, trading days						60 days
Change in control, trading days	60 days
Options, grant date fair value	$ 70,800
2020 Omnibus Incentive Plan | Performance stock units | Chief Executive Officer | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market capitalization baseline multiplier | multiplier	2			2		2
2020 Omnibus Incentive Plan | Performance stock units | Chief Executive Officer | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market capitalization baseline multiplier | multiplier	5			5		5