Postretirement Benefit Plans - Estimated Future Benefit Payments (Detail) $ in Millions	Dec. 31, 2023 USD ($)
Qualified Defined Benefit Pension Plans
Expected Future Benefit Payment [Abstract]
2024	$ 1,790
2025	1,860
2026	1,920
2027	1,970
2028	2,000
2029– 2033	10,020
Retiree Medical and Life Insurance Plans
Expected Future Benefit Payment [Abstract]
2024	130
2025	130
2026	120
2027	120
2028	110
2029– 2033	$ 500

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- Definition

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

+ References

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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- Definition

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

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- Definition

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

+ References

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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.

+ References

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