v3.25.4
PENSION AND OTHER POSTRETIREMENT BENEFITS - Other Postretirement Benefits (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Other Postretirement Benefits    
Assumed health care cost trend rate    
Health care cost trend rate assumed for next year 6.50% 6.50%
Rate that the cost trend rate gradually declines to 5.00% 5.00%
Year that the rate reaches the rate it is assumed to remain at 2031 2031
Without Impact of Medicare Subsidy    
Assumed health care cost trend rate    
2026 $ 11  
2027 11  
2028 10  
2029 10  
2030 9  
2031-2035 39  
Net of Medicare Subsidy    
Assumed health care cost trend rate    
2026 11  
2027 10  
2028 10  
2029 9  
2030 9  
2031-2035 $ 37