Pension and Other Postretirement Benefits - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		$ 1	$ 3	$ 4	$ 8
Interest cost	[1]	25	27	75	81
Expected return on plan assets	[1]	(30)	(34)	(92)	(104)
Recognized net actuarial loss	[1]	9	7	27	23
Curtailments	[2]				1
Settlements	[2]	(1)		(1)	(1)
Net periodic benefit cost		4	3	13	8
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost			1	1	2
Interest cost	[1]	6	6	17	18
Recognized net actuarial loss	[1]	1	1	3	4
Amortization of prior service benefit	[1]	(4)	(3)	(10)	(10)
Net periodic benefit cost		$ 3	$ 5	$ 11	$ 14

[1] These amounts were reported in Other (income) expenses, net on the accompanying Statement of Consolidated Operations (see Note Q).

[2] These amounts were reported in Restructuring and other charges, net on the accompanying Statement of Consolidated Operations and Cash Flows.