Employee Benefit Plans (Components of Net Periodic Benefit Cost (Credit) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2	$ 1	$ 4	$ 4
Interest cost	6	5	11	10
Expected return on assets	(13)	(12)	(25)	(24)
Amortization of actuarial losses	0	1	0	3
Net periodic benefit cost (credit)	(5)	(5)	(10)	(7)
Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	0	1	1
Interest cost	1	2	3	3
Expected return on assets	0	0	0	0
Amortization of actuarial losses	0	0	0	0
Net periodic benefit cost (credit)	$ 2	$ 2	$ 4	$ 4