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) |