v3.26.1
LONG-TERM DEBT - Schedule of Long-term Debt (Details) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Mar. 31, 2026
Dec. 31, 2025
Long-term Debt    
Long-term debt, gross $ 13,757 $ 20,427
Unamortized premium, net 1,012 1,054
Debt issuance costs (62) (84)
Net book value of debt 14,707 21,397
Long-term finance leases 764 801
Current finance leases 200 198
Total debt and finance leases 15,671 22,396
Less: current finance leases (200) (198)
Less: current maturities of long-term debt (224) (1,575)
Long-term debt, net 15,247 20,623
Two-year term loan due 2026 (5.475% as of December 31, 2025) | Secured Debt    
Long-term Debt    
Long-term debt, gross $ 0 $ 1,280
Debt instrument interest rate stated percentage   5.475%
Debt term 2 years 2 years
3.200% senior notes due 2026 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 0 $ 182
Debt instrument interest rate stated percentage 3.20% 3.20%
7.500% debentures due 2026 | Debentures    
Long-term Debt    
Long-term debt, gross $ 0 $ 112
Debt instrument interest rate stated percentage 7.50% 7.50%
8.500% senior notes due 2027 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 0 $ 489
Debt instrument interest rate stated percentage 8.50% 8.50%
3.000% senior notes due 2027 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 0 $ 216
Debt instrument interest rate stated percentage 3.00% 3.00%
7.125% debentures due 2027 | Debentures    
Long-term Debt    
Long-term debt, gross $ 0 $ 150
Debt instrument interest rate stated percentage 7.125% 7.125%
7.000% debentures due 2027 | Debentures    
Long-term Debt    
Long-term debt, gross $ 48 $ 48
Debt instrument interest rate stated percentage 7.00% 7.00%
5.000% senior notes due 2027 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 0 $ 600
Debt instrument interest rate stated percentage 5.00% 5.00%
6.625% debentures due 2028 | Debentures    
Long-term Debt    
Long-term debt, gross $ 14 $ 14
Debt instrument interest rate stated percentage 6.625% 6.625%
7.150% debentures due 2028 | Debentures    
Long-term Debt    
Long-term debt, gross $ 0 $ 232
Debt instrument interest rate stated percentage 7.15% 7.15%
7.200% senior debentures due 2028 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 0 $ 82
Debt instrument interest rate stated percentage 7.20% 7.20%
6.375% senior notes due 2028 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 0 $ 578
Debt instrument interest rate stated percentage 6.375% 6.375%
7.200% debentures due 2029 | Debentures    
Long-term Debt    
Long-term debt, gross $ 135 $ 135
Debt instrument interest rate stated percentage 7.20% 7.20%
7.950% debentures due 2029 | Debentures    
Long-term Debt    
Long-term debt, gross $ 102 $ 116
Debt instrument interest rate stated percentage 7.95% 7.95%
8.450% senior notes due 2029 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 116 $ 116
Debt instrument interest rate stated percentage 8.45% 8.45%
3.500% senior notes due 2029 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 0 $ 286
Debt instrument interest rate stated percentage 3.50% 3.50%
5.200% senior notes due 2029 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 0 $ 1,200
Debt instrument interest rate stated percentage 5.20% 5.20%
Variable rate bonds due 2030 | Variable Rate Bonds    
Long-term Debt    
Long-term debt, gross $ 68 $ 68
8.875% senior notes due 2030 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 1,000 $ 1,000
Debt instrument interest rate stated percentage 8.875% 8.875%
6.625% senior notes due 2030 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 1,068 $ 1,449
Debt instrument interest rate stated percentage 6.625% 6.625%
6.125% senior notes due 2031 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 298 $ 1,143
Debt instrument interest rate stated percentage 6.125% 6.125%
7.500% senior notes due 2031 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 900 $ 900
Debt instrument interest rate stated percentage 7.50% 7.50%
7.875% senior notes due 2031 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 500 $ 500
Debt instrument interest rate stated percentage 7.875% 7.875%
5.375% senior notes due 2032 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 1,000 $ 1,000
Debt instrument interest rate stated percentage 5.375% 5.375%
5.550% senior notes due 2034 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 1,200 $ 1,200
Debt instrument interest rate stated percentage 5.55% 5.55%
6.450% senior notes due 2036 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 1,727 $ 1,727
Debt instrument interest rate stated percentage 6.45% 6.45%
Zero Coupon senior notes due 2036 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 263 $ 285
0.000% loan due 2039 (CAD denominated)    
Long-term Debt    
Long-term debt, gross $ 16 $ 17
0.000% loan due 2039 (CAD denominated) | Secured Debt    
Long-term Debt    
Debt instrument interest rate stated percentage 0.00% 0.00%
4.300% senior notes due 2039 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 247 $ 247
Debt instrument interest rate stated percentage 4.30% 4.30%
7.950% senior notes due 2039 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 325 $ 325
Debt instrument interest rate stated percentage 7.95% 7.95%
6.200% senior notes due 2040 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 737 $ 737
Debt instrument interest rate stated percentage 6.20% 6.20%
4.500% senior notes due 2044 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 191 $ 191
Debt instrument interest rate stated percentage 4.50% 4.50%
4.625% senior notes due 2045 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 296 $ 296
Debt instrument interest rate stated percentage 4.625% 4.625%
6.600% senior notes due 2046 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 1,117 $ 1,117
Debt instrument interest rate stated percentage 6.60% 6.60%
4.400% senior notes due 2046 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 424 $ 424
Debt instrument interest rate stated percentage 4.40% 4.40%
4.100% senior notes due 2047 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 258 $ 258
Debt instrument interest rate stated percentage 4.10% 4.10%
4.200% senior notes due 2048 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 304 $ 304
Debt instrument interest rate stated percentage 4.20% 4.20%
4.400% senior notes due 2049 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 280 $ 280
Debt instrument interest rate stated percentage 4.40% 4.40%
6.050% senior notes due 2054 | Senior Notes    
Long-term Debt    
Long-term debt, gross $ 1,000 $ 1,000
Debt instrument interest rate stated percentage 6.05% 6.05%
7.730% debentures due 2096 | Debentures    
Long-term Debt    
Long-term debt, gross $ 58 $ 58
Debt instrument interest rate stated percentage 7.73% 7.73%
7.500% debentures due 2096 | Debentures    
Long-term Debt    
Long-term debt, gross $ 60 $ 60
Debt instrument interest rate stated percentage 7.50% 7.50%
7.250% debentures due 2096 | Debentures    
Long-term Debt    
Long-term debt, gross $ 5 $ 5
Debt instrument interest rate stated percentage 7.25% 7.25%