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PENSION AND OTHER POSTEMPLOYMENT BENEFITS - Pension Investments Measured at Fair Value (Details) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Pension |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 6,249 | $ 6,927
Asset Allocation | 100.00% | 100.00%
Excluded from total investments | $ 47 | $ (48)
Pension | Investments Excluding in Investments at NAV |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 4,130 | $ 4,393
Asset Allocation | 66.00% | 63.00%
Pension | Cash and short-term securities |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 1,173 | $ 755
Asset Allocation | 19.00% | 11.00%
Pension | Public equity |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 1,590 | $ 1,815
Asset Allocation | 25.00% | 26.00%
Pension | Fixed income |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 1,425 | $ 1,784
Asset Allocation | 23.00% | 26.00%
Pension | Derivatives |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value |  | $ 39
Asset Allocation |  | 0.00%
Pension | Derivatives |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ (58) |
Asset Allocation | (1.00%) |
Pension | Private - equity and debt funds |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 1,273 | $ 1,296
Asset Allocation | 20.00% | 19.00%
Pension | Insurance-linked securities |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 39 | $ 107
Asset Allocation | 1.00% | 2.00%
Pension | Hedge funds |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 253 | $ 410
Asset Allocation | 4.00% | 6.00%
Pension | Real estate funds |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 554 | $ 721
Asset Allocation | 9.00% | 10.00%
Pension | Level 1 | Investments Excluding in Investments at NAV |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 1,490 | $ 1,813
Pension | Level 1 | Cash and short-term securities |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 0 | 0
Pension | Level 1 | Public equity |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 1,585 | 1,811
Pension | Level 1 | Fixed income |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 0 | 0
Pension | Level 1 | Derivatives |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value |  | 2
Pension | Level 1 | Derivatives |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | (95) |
Pension | Level 2 | Investments Excluding in Investments at NAV |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 2,640 | 2,580
Pension | Level 2 | Cash and short-term securities |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 1,173 | 755
Pension | Level 2 | Public equity |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 5 | 4
Pension | Level 2 | Fixed income |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 1,425 | 1,784
Pension | Level 2 | Derivatives |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value |  | 37
Pension | Level 2 | Derivatives |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 37 |
Pension | Level 3 | Investments Excluding in Investments at NAV |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 0 | 0
Pension | Level 3 | Cash and short-term securities |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 0 | 0
Pension | Level 3 | Public equity |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 0 | 0
Pension | Level 3 | Fixed income |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 0 | 0
Pension | Level 3 | Derivatives |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value |  | 0
Pension | Level 3 | Derivatives |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 0 |
OPEB |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 572 | $ 516
Asset Allocation | 100.00% | 100.00%
Excluded from total investments |  | $ (5)
OPEB | Cash and short-term securities |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 112 | $ 100
Asset Allocation | 20.00% | 19.00%
OPEB | Public equity |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 314 | $ 258
Asset Allocation | 55.00% | 50.00%
OPEB | Fixed income |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 146 | $ 158
Asset Allocation | 25.00% | 31.00%
OPEB | Level 1 |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 314 | $ 258
OPEB | Level 1 | Cash and short-term securities |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 0 | 0
OPEB | Level 1 | Public equity |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 314 | 258
OPEB | Level 1 | Fixed income |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 0 | 0
OPEB | Level 2 |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 258 | 258
OPEB | Level 2 | Cash and short-term securities |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 112 | 100
OPEB | Level 2 | Public equity |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 0 | 0
OPEB | Level 2 | Fixed income |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 146 | 158
OPEB | Level 3 |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 0 | 0
OPEB | Level 3 | Cash and short-term securities |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 0 | 0
OPEB | Level 3 | Public equity |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | 0 | 0
OPEB | Level 3 | Fixed income |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Pension investments measured at fair value | $ 0 | $ 0

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