Employee Benefit Plans (Schedule of Fair Value Measurements By Category) (Parenthetical) (Detail) - Pension Benefits [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Pending sales of securities	$ 1	$ 1
Net accrued income	1	1
Pending purchases of securities	$ 6	$ 15