Employee Benefits - Postretirement Benefits Other Than Pension Expenses (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	$ (2)	$ (1)
Defined Contribution and Other Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Interest cost on projected benefit obligation	1	1
Net amortization and deferrals	0	(1)
Net periodic benefit cost	$ 1	$ 0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details