Employee Postretirement Benefits - Schedule of Amounts Recognized in Balance Sheet (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	$ 78	$ 0
Accrued benefit costs and other current liabilities	(3)	(1)
Deferred credits and other liabilities	(12)	(15)
Net amount recognized at end of year	63	(16)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	0	0
Accrued benefit costs and other current liabilities	(12)	(12)
Deferred credits and other liabilities	(175)	(186)
Net amount recognized at end of year	$ (187)	$ (198)