Employee Benefit Plans (Components of Net Periodic Benefit Cost (Credit) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2	$ 3
Interest cost	5	5
Expected return on assets	(12)	(12)
Amortization of actuarial losses	0	2
Net periodic benefit cost (credit)	(5)	(2)
Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	1
Interest cost	2	1
Expected return on assets	0	0
Amortization of actuarial losses	0	0
Net periodic benefit cost (credit)	$ 2	$ 2