Employee Postretirement Benefits - Schedule of Amounts Recognized in Balance Sheet (Detail) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	$ 14	$ 10
Accrued benefit costs and other current liabilities	0	0
Deferred credits and other liabilities	(2)	(1)
Net amount recognized at end of year	12	9
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	0	0
Accrued benefit costs and other current liabilities	(10)	(10)
Deferred credits and other liabilities	(97)	(99)
Net amount recognized at end of year	$ (107)	$ (109)