v3.26.3
Debt and Derivatives - Schedule of Debt (Details)
$ in Millions, $ in Millions
Sep. 30, 2026
USD ($)
Sep. 30, 2026
CAD ($)
Jul. 31, 2026
CAD ($)
Jun. 30, 2026
Dec. 31, 2025
USD ($)
Debt          
Weighted average interest rate, finance leases 4.91% 4.91%     4.83%
Financing leases and other, maturing through 2075 (weighted average interest rate of 4.91% as of September 30, 2026 and 4.83% as of December 31, 2025) $ 1,630       $ 1,284
Debt issuance costs, discounts and other (147)       (156)
Long-term debt and finance leases 23,370       22,907
Current portion of long-term debt 1,524       711
Long-term debt, less current portion $ 21,846       $ 22,196
$3.5 Billion Revolving Credit Facility | Commercial Paper          
Debt          
Weighted average interest rate 4.01% 4.01%     4.05%
Long-term debt $ 1,250       $ 1,090
Senior Notes Due 2054 | Senior Notes          
Debt          
Weighted average interest rate 4.23% 4.23%     4.28%
Long-term debt $ 17,218       $ 17,498
Senior Notes Due 2054 | Minimum | Senior Notes          
Debt          
Interest rate (as a percent) 1.15% 1.15%      
Senior Notes Due 2054 | Maximum | Senior Notes          
Debt          
Interest rate (as a percent) 7.75% 7.75%      
Canadian Senior Notes Due 2026 | Senior Notes          
Debt          
Interest rate (as a percent)     2.60%    
Long-term debt $ 0   $ 500   364
Canadian Senior Notes Due 2033 | Senior Notes          
Debt          
Interest rate (as a percent) 3.944% 3.944%   3.944%  
Long-term debt $ 492 $ 700     $ 0
Tax Exempt Bonds Due 2055 | Bonds          
Debt          
Weighted average interest rate 3.25% 3.25%     3.41%
Long-term debt $ 2,927       $ 2,827
Tax Exempt Bonds Due 2055 | Minimum | Bonds          
Debt          
Interest rate (as a percent) 0.95% 0.95%      
Tax Exempt Bonds Due 2055 | Maximum | Bonds          
Debt          
Interest rate (as a percent) 4.60% 4.60%