Employee Benefit Plans (Components of Provision for Net Periodic Benefit (Credit) Cost) (Detail) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
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| Pension Benefits | ||||
| Defined Benefit Plan Disclosure [Line Items] | ||||
| Service cost | $ 19 | $ 19 | $ 57 | $ 57 |
| Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration] | Other Nonoperating Income (Expense) | Other Nonoperating Income (Expense) | Other Nonoperating Income (Expense) | Other Nonoperating Income (Expense) |
| Interest cost | $ 108 | $ 108 | $ 323 | $ 325 |
| Expected return on plan assets | (159) | (170) | (476) | (508) |
| Amortization of prior service cost (credit) | 0 | 1 | 1 | 1 |
| Net periodic benefit (credit) cost | (32) | (42) | (95) | (125) |
| Other Postretirement Benefits | ||||
| Defined Benefit Plan Disclosure [Line Items] | ||||
| Service cost | $ 2 | $ 3 | $ 7 | $ 8 |
| Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration] | Other Nonoperating Income (Expense) | Other Nonoperating Income (Expense) | Other Nonoperating Income (Expense) | Other Nonoperating Income (Expense) |
| Interest cost | $ 13 | $ 13 | $ 40 | $ 42 |
| Expected return on plan assets | (43) | (39) | (130) | (119) |
| Amortization of prior service cost (credit) | (5) | (6) | (16) | (19) |
| Net periodic benefit (credit) cost | $ (33) | $ (29) | $ (99) | $ (88) |
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- Definition Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition 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. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of cost recognized for passage of time related to defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of net periodic benefit cost (credit) for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Indicates line item in statement of income or comprehensive income that includes components of net periodic benefit cost (credit), excluding service cost component, for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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