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RETIREMENT BENEFITS - Narrative (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items] |  |
Plan asset amortization period | 5 years |
Pension plans |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Employer contributions | $ 65,000,000 | $ 52,000,000
Expected future employer contributions, next fiscal year | 0 |
Actuarial losses | $ (887,000,000) | $ 493,000,000
Change in discount rate | 0.69% | 0.18%
Pension plans | Qualified pension plan |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Employer contributions | $ 0 |
Other postretirement benefit plans |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Employer contributions | 55,000,000 | $ 73,000,000
Expected future employer contributions, next fiscal year | 0 |
Actuarial losses | $ (2,000,000) | $ (33,000,000)

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- Definition Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a)(4) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
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