Employee Benefit Plans (Components of Net Periodic Benefit Cost (Credit) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2	$ 2	$ 6	$ 6
Interest cost	8	5	24	16
Expected return on assets	(8)	(12)	(25)	(37)
Amortization of actuarial losses	3	1	9	1
Net periodic benefit cost (credit)	5	(4)	14	(14)
Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	1	1
Interest cost	2	1	6	4
Expected return on assets	0	0	0	0
Amortization of actuarial losses	(1)		(3)
Net periodic benefit cost (credit)	$ 1	$ 1	$ 4	$ 5