Pension Plans and Other Post-Retirement Benefit Plans - Components of Net Periodic Benefit Cost for Pension Plans and Other Post-Retirement Benefit Plans (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 6	$ 7
Interest expense	9	8
Expected return on plan assets	(19)	(16)
Amortization of net actuarial loss		2
Net periodic benefit cost	(4)	$ 1
Other Post-Retirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest expense	1
Net periodic benefit cost	$ 1