Description of Business and Summary of Significant Accounting Policies (Details)		3 Months Ended		9 Months Ended
	Apr. 19, 2021 USD ($) vote d $ / shares shares	Sep. 30, 2021 USD ($) shares	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) shares	Sep. 30, 2020 USD ($)	Dec. 31, 2020 shares
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Stock-based compensation expense | $		$ 32,082,000	$ 7,645,000	$ 90,880,000	$ 9,325,000
Time Based Service Awards
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Share based compensation, option vesting period				4 years
Performance Based Awards
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Share based compensation, option vesting period				4 years
Employee Stock
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Stock-based compensation expense | $		$ 200,000		$ 200,000
Common Class A
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Common stock, shares authorized (in shares)		4,876,000,000		4,876,000,000		361,897,230
Number of votes per share | vote	1
Maximum purchase amount | $				$ 25,000
Maximum number of shares per employee (in shares)				1,500
Common Class A | Employee Stock
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Offering period				6 months
Purchase price of common stock, percentage of fair market value				15.00%
Common Class B
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Common stock, shares authorized (in shares)		24,000,000		24,000,000		0
Number of votes per share | vote	10
Initial Public Offering
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Preferred stock, authorized (in shares)	100,000,000
Number of redeemable convertible preferred stock converted (in shares)	120,534,419
Stock-based compensation expense | $	$ 42,600,000			$ 42,600,000
Initial Public Offering | Performance Based Awards
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Share based compensation, option vesting period				4 years
Initial Public Offering | Former Employees
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Stock-based compensation expense | $	$ 4,300,000
Initial Public Offering | Common Class A
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Number of shares issued and sold (in shares)	27,027,027
Price per share (in dollars per share) | $ / shares	$ 40.00
Net proceeds after deducting underwriting discounts and commissions and offering costs | $	$ 1,000,000,000
Underwriting discounts and commissions | $	$ 50,100,000
Common stock, shares authorized (in shares)	4,876,000,000
Number of redeemable convertible preferred stock converted (in shares)	120,534,419
Initial Public Offering | Common Class A | Founders
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Common stock, shares exchanged into Class B common stock (in shares)	12,000,000
Initial Public Offering | Common Class B
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Common stock, shares authorized (in shares)	24,000,000
Percentage of outstanding shares threshold	75.00%
Initial Public Offering | Common Class B | Founders
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Maximum stock conversion outstanding shares threshold	12,000,000
Initial Public Offering | Common Class B | Founders | Minimum
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Stock conversion threshold days | d	61
Initial Public Offering | Common Class B | Founders | Maximum
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Stock conversion threshold days | d	180
Initial Public Offering | Common Class B | Death or Incapacitation of Last Founder | Minimum
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Stock conversion threshold days | d	90
Initial Public Offering | Common Class B | Death or Incapacitation of Last Founder | Maximum
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Stock conversion threshold days | d	270
Private Placement | Common Class A
Description Of Business And Summary Of Significant Accounting Policies Disclosure [Line Items]
Number of shares issued and sold (in shares)	874,999