Employee Benefit Plans (AOCI and Regulatory Assets and Liabilities that have Not been Recognized as Components of Periodic Benefit (Credit) Cost) (Parenthetical) (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Assets and Liabilities Held for Sale
Defined Benefit Plan Disclosure [Line Items]
Amount in regulatory assets and liabilities	$ 173