Stock-Based Compensation - Narrative (Details) $ / shares in Units, $ in Thousands			1 Months Ended			2 Months Ended	3 Months Ended		9 Months Ended
	Sep. 29, 2021 shares	Jun. 15, 2021 tranche shares	Aug. 31, 2021 USD ($) $ / shares shares	Jun. 30, 2021 USD ($) performanceCondition shares	May 31, 2021 USD ($)	Sep. 30, 2021 USD ($) shares	Sep. 30, 2021 USD ($) shares	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) $ / shares shares	Sep. 30, 2020 USD ($) shares	Dec. 31, 2020 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual increase in shares authorized as a percent of common stock outstanding			1.00%
Total stock-based compensation expense | $			$ 6,800				$ 64,332	$ 42,377	$ 76,002	$ 43,749
Stock options granted in period (in shares)			387,277						1,226,277
Expected term							3 months
Options granted (in dollars per share) | $ / shares			$ 24.53						$ 20.20
Cash received from options exercised | $						$ 9,000
Direct Listing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense | $							$ 25,300		$ 25,300
Private Placement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense | $								$ 41,700		$ 41,700
Tender Offer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense | $					$ 9,200				9,200
Series A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted in period (in shares)			40,766
Series B common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted in period (in shares)			346,511
The Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted in period (in shares)										0
Non-vested option, cost not yet recognized | $						$ 10,600	10,600		10,600
2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual increase in shares authorized, percent			5.00%
2021 Plan | Series A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized			11,076,515
The Founders Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense | $							$ 28,800		$ 28,800
Stock options or restricted stock units (RSUs) | The Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized											14,901,474
Stock options or restricted stock units (RSUs) | The Plans | Series A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized											6,439,492
Number of additional shares authorized				6,500,000
Stock options or restricted stock units (RSUs) | The Plans | Series B common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized											8,461,982
Number of additional shares authorized				1,200,000
Stock options or restricted stock units (RSUs) | 2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized						11,877,916	11,877,916		11,877,916
Award vesting period									4 years
Restricted stock units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units vested (in shares)									1,064,858
Total stock-based compensation expense | $							$ 12,900		$ 12,900
Granted (in shares)									3,089,923
Restricted stock units (RSUs) | The Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cost not yet recognized, outstanding awards | $						$ 81,100	81,100		$ 81,100
Restricted stock units (RSUs) | 2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units vested (in shares)	936,646
Restricted stock units (RSUs) | 2021 Plan | Series A or Series B common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares receivable per share based payments award (in shares)									1
Restricted stock units (RSUs) | The Founders Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				5 years
Total stock-based compensation expense | $			$ 2,300	$ 1,800
Granted (in shares)		1,884,724
Grant date fair value | $									$ 66,900
Performance stock units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of performance conditions | performanceCondition				2
Terms of award, stock price hurdle period				10 years
Award expiration period				10 years
Total stock-based compensation expense | $							15,900		15,900
Performance stock units (PSUs) | Monte Carlo simulation
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value | $									128,800
Performance stock units (PSUs) | Series B common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares receivable per share based payments award (in shares)				1
Performance stock units (PSUs) | The Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cost not yet recognized, outstanding awards | $						$ 112,900	$ 112,900		$ 112,900
Performance stock units (PSUs) | The Founders Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period									90 days
Terms of award, stock price hurdle period				10 years
Granted (in shares)		4,397,688
Number of tranches | tranche		8
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of additional shares authorized			2,215,303						16,614,772
Stock options | The Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period									4 years
Award expiration period				10 years
Risk free interest rate, coupon rate assumption used									0.00%
Expected dividend yield							0.00%		0.00%
Award contractual period									10 years
Expected term									6 years 3 months
Non-vested award, cost not yet recognized, period for recognition									1 year 3 months 3 days