Employee Benefit Plans (Schedule of Fair Value Measurements By Category) (Parenthetical) (Detail) - Pension Benefits $ in Millions	12 Months Ended
Dec. 31, 2021 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Pending sales of securities	$ 4
Net accrued income	2
Pending purchases of securities	$ 25

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration