Stock-Based Compensation - Summary of The Activity of Restricted Stock And Restricted Stock Units Granted By The Company (Parenthetical) (Detail) - shares	3 Months Ended
Mar. 31, 2022	Dec. 31, 2021
Unvested restricted stock	68,663,660	65,208,870
Restricted Stock [Member]
Number of shares available for grant	4,162,159
Number of shares forfeited during period	717,505
Unvested Restricted Stock [Member]
Unvested restricted stock	1,263,867
Restricted Stock Units (RSUs) [Member]
Number of shares available for grant	65,710
Number of shares forfeited during period	55,574
Unvested Class A Restricted Stock [Member]
Unvested restricted stock	47,962,958	44,518,304
Unvested Class B Restricted Stock [Member]
Unvested restricted stock	19,436,835	19,436,835

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant