Significant Accounting Policies - Reclassifications Out of Accumulated Other Comprehensive Loss (Detail) - Pension and Postretirement Benefit Plans - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Earnings from Continuing Operations	$ 5	$ 2	$ 7	$ 4
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Settlement charge	5	0	5	0
Amortization of Actuarial loss	0	0	0	1
Tax effect	(1)	0	(2)	(2)
Earnings from Continuing Operations	5	2	7	4
Reclassification out of Accumulated Other Comprehensive Income \| Other Nonoperating Income, Net
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service cost	1	2	4	5
Total reclassifications out of accumulated other comprehensive loss before taxes	$ 6	$ 2	$ 9	$ 6

Amount, before tax, of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) of defined benefit plan.

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Amount, before tax, of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan.

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Amount before tax of reclassification adjustments of other comprehensive income (loss).

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Amount after tax of reclassification adjustments of other comprehensive income (loss).

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Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income (loss).

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