Employee Benefits - Postretirement Benefits Other Than Pension Expenses (Detail) - Defined Contribution and Other Retirement Plans - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	$ 0	$ 1	$ 0	$ 1
Interest cost on projected benefit obligation	0	0	2	1
Net amortization and deferrals	(1)	(2)	(4)	(4)
Net periodic benefit (income) cost	$ (1)	$ (1)	$ (2)	$ (2)