Commitments and Contingencies (Charitable Commitments) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2023	Dec. 31, 2022
Other Deferred Credits and Other Liabilities
Recorded Unconditional Purchase Obligation [Line Items]
Charitable commitments		$ 8	$ 32
Other Current Liabilities
Recorded Unconditional Purchase Obligation [Line Items]
Charitable commitments		$ 6	$ 11
Other Income
Recorded Unconditional Purchase Obligation [Line Items]
Charitable expenses	$ 80