Restricted Net Assets - Additional Information (Detail) ¥ in Millions, $ in Millions	12 Months Ended
Dec. 31, 2020 CNY (¥)	Dec. 31, 2021 CNY (¥)	Dec. 31, 2021 USD ($)
Restricted Net Assets [Abstract]
Percentage of net after-tax income of Group's subsidiary and VIE required to be annually appropriated to the statutory general reserve fund	10.00%
Limit of statutory reserve fund as a percentage of registered capital, after which allocations to statutory reserve fund are no longer required	50.00%
Amounts restricted including paid in capital and statutory reserve funds	¥ 6,259	¥ 6,301	$ 989

Amount of restricted net assets of consolidated and unconsolidated subsidiaries as of the end of the most recently completed fiscal year.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e)(3)(ii))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Name:	us-gaap_AmountOfRestrictedNetAssetsForConsolidatedAndUnconsolidatedSubsidiaries
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant