PENSIONS AND OTHER POSTRETIREMENT BENEFITS - Contributions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions	$ 68	$ 119
Pension benefits, employer contributions and payments	68
Expected employer contributions, next fiscal year	43
OPEB
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions	86	76
Employer contributions	86	76
Expected employer contributions, next fiscal year	83
OPEB | VEBA
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions	0	0
Expected employer contributions, next fiscal year	0
OPEB | Direct Payments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions	86	$ 76
Expected employer contributions, next fiscal year	$ 83