v3.26.1
Earnings Per Share (Summary of Earnings Per Share) (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Basic earnings per share:    
Net income attributable to MPC $ 511 $ (74)
Income allocated to participating securities, basic 0 0
Income (loss) available to common stockholders - basic $ 511 $ (74)
Weighted average common shares outstanding - basic (in shares) 295 313
Basic earnings (loss) per share $ 1.73 $ (0.24)
Diluted earnings per share:    
Net income attributable to MPC $ 511 $ (74)
Income allocated to participating securities, diluted 0 0
Income (loss) available to common stockholders - diluted $ 511 $ (74)
Weighted average common shares outstanding - basic (in shares) 295 313
Effect of dilutive securities (in shares) 0 0
Weighted average shares outstanding - diluted (in shares) 295 313
Diluted earnings (loss) per share $ 1.73 $ (0.24)