v3.25.4
Debt - Schedule of Debt (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Nov. 30, 2024
Debt Instrument [Line Items]      
Finance leases $ 801 $ 940  
Net unamortized premiums, discounts and debt issuance costs (704) (701)  
Total debt 23,444 24,324  
Short-term debt (1,020) (1,035)  
Long-term debt 22,424 23,289  
Debt at face value 23,347 24,085  
Notes Payable to Banks | Marathon Oil Corporation      
Debt Instrument [Line Items]      
Debt at face value     $ 4,600
Variable Rate Debt Bonds      
Debt Instrument [Line Items]      
Debt at face value $ 283 283  
2.4% Notes due 2025 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 2.40%    
Long-term and short-term, combined amount, gross $ 0 366  
8.2% Debentures due 2025 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 8.20%    
Long-term and short-term, combined amount, gross $ 0 134  
3.35% Notes due 2025 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 3.35%    
3.35% Notes due 2025 | Debentures      
Debt Instrument [Line Items]      
Stated interest rate 3.35%    
Long-term and short-term, combined amount, gross $ 0 199  
6.875% Debentures due 2026 | Debentures      
Debt Instrument [Line Items]      
Stated interest rate 6.875%    
Long-term and short-term, combined amount, gross $ 67 $ 67  
7.8% Debentures due 2027 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate   7.80%  
Debt at face value   $ 203  
7.8% Debentures due 2027 | Debentures      
Debt Instrument [Line Items]      
Stated interest rate 7.80%    
Long-term and short-term, combined amount, gross $ 120 120  
4.4% Notes due 2027 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 4.40%    
Long-term and short-term, combined amount, gross $ 422 $ 424  
4.4% Notes due 2027 | Notes Payable to Banks | Marathon Oil Corporation      
Debt Instrument [Line Items]      
Stated interest rate   4.40% 4.40%
Debt at face value     $ 1,000
3.75% Notes due 2027 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 3.75%    
Long-term and short-term, combined amount, gross $ 196 $ 196  
4.3% Notes due 2028 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 4.30%    
Long-term and short-term, combined amount, gross $ 223 $ 223  
7.375% Debentures due 2029 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate   7.375%  
Debt at face value   $ 92  
7.375% Debentures due 2029 | Debentures      
Debt Instrument [Line Items]      
Stated interest rate 7.375%    
Long-term and short-term, combined amount, gross $ 66 $ 66  
7.0% Debentures due 2029 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate   7.00%  
Debt at face value   $ 112  
7.0% Debentures due 2029 | Debentures      
Debt Instrument [Line Items]      
Stated interest rate 7.00%    
Long-term and short-term, combined amount, gross $ 95 95  
5.3% Notes due 2029 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.30%    
Long-term and short-term, combined amount, gross $ 84 $ 86  
5.3% Notes due 2029 | Notes Payable to Banks | Marathon Oil Corporation      
Debt Instrument [Line Items]      
Stated interest rate     5.30%
Debt at face value     $ 600
6.95% Notes due 2029 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 6.95% 6.95%  
Long-term and short-term, combined amount, gross $ 705 $ 705  
Debt at face value   1,195  
4.7% Notes due 2030 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 4.70%    
Long-term and short-term, combined amount, gross $ 1,350 $ 1,350  
8.125% Notes due 2030 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 8.125% 8.125%  
Long-term and short-term, combined amount, gross $ 207 $ 207  
Debt at face value   390  
2.4% Notes due 2031 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 2.40%    
Long-term and short-term, combined amount, gross $ 227 227  
7.2% Notes due 2031 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 7.20%    
Long-term and short-term, combined amount, gross $ 447 $ 447  
7.25% Notes due 2031 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 7.25% 7.25%  
Long-term and short-term, combined amount, gross $ 268 $ 268  
Debt at face value   $ 400  
7.4% Notes due 2031 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 7.40% 7.40%  
Long-term and short-term, combined amount, gross $ 232 $ 232  
Debt at face value   382  
4.85% Notes due 2032 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 4.85%    
Long-term and short-term, combined amount, gross $ 650 650  
6.8% Notes due 2032 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 6.80%    
Long-term and short-term, combined amount, gross $ 180 $ 180  
6.8% Notes due 2032 | Notes Payable to Banks | Marathon Oil Corporation      
Debt Instrument [Line Items]      
Stated interest rate   6.80% 6.80%
Debt at face value     $ 550
5.9% Notes due 2032 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.90%    
Long-term and short-term, combined amount, gross $ 505 $ 505  
5.05% Notes due 2033 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.05%    
Long-term and short-term, combined amount, gross $ 1,000 1,000  
5.7% Notes due 2034 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.70%    
Long-term and short-term, combined amount, gross $ 103 $ 103  
5.7% Notes due 2034 | Notes Payable to Banks | Marathon Oil Corporation      
Debt Instrument [Line Items]      
Stated interest rate   5.70% 5.70%
Debt at face value     $ 600
4.15% Notes due 2034 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 4.15%    
Long-term and short-term, combined amount, gross $ 246 $ 246  
5.0% Notes due 2035 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.00%    
Long-term and short-term, combined amount, gross $ 1,250 1,250  
5.95% Notes due 2036 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.95%    
Long-term and short-term, combined amount, gross $ 326 326  
5.951% Notes serially maturing 2022 through 2037 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.951%    
Long-term and short-term, combined amount, gross $ 541 573  
6.6% Notes due 2037 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 6.60%    
Long-term and short-term, combined amount, gross $ 335 $ 335  
6.6% Notes due 2037 | Notes Payable to Banks | Marathon Oil Corporation      
Debt Instrument [Line Items]      
Stated interest rate   6.60% 6.60%
Debt at face value     $ 750
5.9% Notes due 2038 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.90%    
Long-term and short-term, combined amount, gross $ 350 $ 350  
6.5% Notes due 2039 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 6.50%    
Long-term and short-term, combined amount, gross $ 1,588 1,588  
3.758% Notes due 2042 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 3.758%    
Long-term and short-term, combined amount, gross $ 785 785  
4.3% Notes due 2044 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 4.30%    
Long-term and short-term, combined amount, gross $ 750 750  
5.2% Notes due 2045 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.20%    
Long-term and short-term, combined amount, gross $ 186 $ 186  
5.2% Notes due 2045 | Notes Payable to Banks | Marathon Oil Corporation      
Debt Instrument [Line Items]      
Stated interest rate   5.20% 5.20%
Debt at face value     $ 500
5.95% Notes due 2046 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.95%    
Long-term and short-term, combined amount, gross $ 329 $ 329  
7.9% Debentures due 2047 | Debentures      
Debt Instrument [Line Items]      
Stated interest rate 7.90%    
Long-term and short-term, combined amount, gross $ 60 60  
4.875% Notes due 2047 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 4.875%    
Long-term and short-term, combined amount, gross $ 319 319  
4.85% Notes due 2048 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 4.85%    
Long-term and short-term, combined amount, gross $ 219 219  
3.8% Notes due 2052 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 3.80%    
Long-term and short-term, combined amount, gross $ 1,100 1,100  
5.3% Notes due 2053 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.30%    
Long-term and short-term, combined amount, gross $ 1,100 1,100  
5.55% Notes due 2054 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.55%    
Long-term and short-term, combined amount, gross $ 1,000 1,000  
5.5% Notes due 2055 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.50%    
Long-term and short-term, combined amount, gross $ 1,300 1,300  
4.025% Notes due 2062 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 4.025%    
Long-term and short-term, combined amount, gross $ 1,770 1,770  
5.7% Notes due 2063 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.70%    
Long-term and short-term, combined amount, gross $ 700 700  
5.65% Notes due 2065 | Notes Payable to Banks      
Debt Instrument [Line Items]      
Stated interest rate 5.65%    
Long-term and short-term, combined amount, gross $ 650 650  
Marine Terminal Revenue Refunding Bonds due 2031 at 1.23% – 5.05% during 2025 and 1.78% – 4.80% during 2024 | Variable Rate Debt Bonds      
Debt Instrument [Line Items]      
Long-term and short-term, combined amount, gross $ 265 $ 265  
Marine Terminal Revenue Refunding Bonds due 2031 at 1.23% – 5.05% during 2025 and 1.78% – 4.80% during 2024 | Variable Rate Debt Bonds | Minimum      
Debt Instrument [Line Items]      
Stated interest rate 1.23% 1.78%  
Marine Terminal Revenue Refunding Bonds due 2031 at 1.23% – 5.05% during 2025 and 1.78% – 4.80% during 2024 | Variable Rate Debt Bonds | Maximum      
Debt Instrument [Line Items]      
Stated interest rate 5.05% 4.80%  
Industrial Development Bonds due 2035 at 1.23% – 5.05% during 2025 and 1.78% – 4.22% during 2024 | Variable Rate Debt Bonds      
Debt Instrument [Line Items]      
Long-term and short-term, combined amount, gross $ 18 $ 18  
Industrial Development Bonds due 2035 at 1.23% – 5.05% during 2025 and 1.78% – 4.22% during 2024 | Variable Rate Debt Bonds | Minimum      
Debt Instrument [Line Items]      
Stated interest rate 1.23% 1.78%  
Industrial Development Bonds due 2035 at 1.23% – 5.05% during 2025 and 1.78% – 4.22% during 2024 | Variable Rate Debt Bonds | Maximum      
Debt Instrument [Line Items]      
Stated interest rate 5.05% 4.22%  
2.20% Revenue Refunding Bonds      
Debt Instrument [Line Items]      
Stated interest rate     2.20%
Debt at face value     $ 200
2.20% Revenue Refunding Bonds | Variable Rate Debt Bonds      
Debt Instrument [Line Items]      
Long-term and short-term, combined amount, gross $ 200    
2.20% Revenue Refunding Bonds | Variable Rate Debt Bonds | Marathon Oil Corporation      
Debt Instrument [Line Items]      
Stated interest rate 2.20%    
2.375% Revenue Refunding Bonds      
Debt Instrument [Line Items]      
Stated interest rate     2.375%
Debt at face value     $ 200
2.375% Revenue Refunding Bonds | Variable Rate Debt Bonds      
Debt Instrument [Line Items]      
Long-term and short-term, combined amount, gross $ 200    
2.375% Revenue Refunding Bonds | Variable Rate Debt Bonds | Marathon Oil Corporation      
Debt Instrument [Line Items]      
Stated interest rate 2.375%    
4.05% Revenue Refunding Bonds      
Debt Instrument [Line Items]      
Stated interest rate     4.05%
Debt at face value     $ 200
4.05% Revenue Refunding Bonds | Variable Rate Debt Bonds      
Debt Instrument [Line Items]      
Long-term and short-term, combined amount, gross $ 200    
4.05% Revenue Refunding Bonds | Variable Rate Debt Bonds | Marathon Oil Corporation      
Debt Instrument [Line Items]      
Stated interest rate 4.05%    
3.30% Revenue Refunding Bonds | Variable Rate Debt Bonds      
Debt Instrument [Line Items]      
Stated interest rate 3.30%    
Long-term and short-term, combined amount, gross $ 400    
Revenue Refunding Bonds Due 2037 | Variable Rate Debt Bonds      
Debt Instrument [Line Items]      
Long-term and short-term, combined amount, gross 1,000 $ 1,000  
Other      
Debt Instrument [Line Items]      
Long-term and short-term, combined amount, gross $ 13 $ 16