Pension and Other Postretirement Employee Benefits (OPEB) Plans - Schedule of Expected Benefit Payments (Details) $ in Millions	Dec. 31, 2024 USD ($)
Pension costs
Defined Benefit Plans and Other Postretirement Benefit Plans
2025	$ 33
2026	34
2027	43
2028	32
2029	32
2030-2034	151
OPEB costs
Defined Benefit Plans and Other Postretirement Benefit Plans
2025	9
2026	9
2027	9
2028	8
2029	8
2030-2034	$ 36

Amount of benefit for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following current fiscal year.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

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Amount of benefit for defined benefit plan expected to be paid in next fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in fifth fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in fourth fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in third fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in second fiscal year following current fiscal year.

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