Employee Benefits - Postretirement Benefits Other Than Pension Expenses (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit (income) cost	$ (1)	$ (5)
Defined Contribution and Other Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Interest cost on projected benefit obligation	1	1
Net amortization and deferrals	(1)	(1)
Net periodic benefit (income) cost	$ 0	$ 0