Employee Benefit Plans (Components of Net Periodic Benefit Cost) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 9	$ 12	$ 15
Interest cost	20	24	28
Expected return on assets	(48)	(45)	(40)
Prior service cost amortization		0	0
Amortization of actuarial losses	6	6	11
Settlement loss		7	16
Curtailment		0	6
Net periodic benefit cost	(13)	4	36
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	3	3
Interest cost	6	8	9
Prior service cost amortization	0
Amortization of actuarial losses			0
Settlement loss	0	0
Curtailment	0	0	3
Net periodic benefit cost	$ 7	$ 11	$ 15