Employee Benefit Plans (Benefit Obligation in Excess of Plan Assets) (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation	$ 7,996	$ 7,655
Fair value of plan assets	7,697	7,410
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation	195	197
Fair value of plan assets	$ 4	$ 5