v3.25.2
Properties (Details) - USD ($)
$ in Millions
 3 Months Ended
Jun. 30, 2024
Jun. 30, 2025
Dec. 31, 2024
Property, Plant and Equipment [Line Items]      
Cost   $ 85,173 $ 83,840
Accumulated depreciation   26,156 25,497
Net book value   59,017 58,343
Land      
Property, Plant and Equipment [Line Items]      
Cost   5,450 5,441
Net book value   5,450 5,441
Total road      
Property, Plant and Equipment [Line Items]      
Cost   62,885 62,049
Accumulated depreciation   20,145 19,614
Net book value   42,740 42,435
Rail and other track material      
Property, Plant and Equipment [Line Items]      
Cost   19,515 19,283
Accumulated depreciation   7,797 7,642
Net book value   $ 11,718 $ 11,641
Estimated useful life   45 years 46 years
Ties      
Property, Plant and Equipment [Line Items]      
Cost   $ 12,593 $ 12,358
Accumulated depreciation   4,206 4,109
Net book value   $ 8,387 $ 8,249
Estimated useful life   34 years 34 years
Ballast      
Property, Plant and Equipment [Line Items]      
Cost   $ 6,575 $ 6,495
Accumulated depreciation   2,245 2,182
Net book value   $ 4,330 $ 4,313
Estimated useful life   34 years 34 years
Other roadway      
Property, Plant and Equipment [Line Items]      
Cost   $ 24,202 $ 23,913
Accumulated depreciation   5,897 5,681
Net book value   $ 18,305 $ 18,232
Estimated useful life   47 years 47 years
Total equipment      
Property, Plant and Equipment [Line Items]      
Cost   $ 14,143 $ 13,750
Accumulated depreciation   5,387 5,243
Net book value   8,756 8,507
Locomotives      
Property, Plant and Equipment [Line Items]      
Cost   9,793 9,517
Accumulated depreciation   3,799 3,724
Net book value   $ 5,994 $ 5,793
Estimated useful life   18 years 18 years
Freight cars      
Property, Plant and Equipment [Line Items]      
Cost   $ 3,077 $ 3,011
Accumulated depreciation   1,073 1,037
Net book value   $ 2,004 $ 1,974
Estimated useful life   23 years 22 years
Work equipment and other      
Property, Plant and Equipment [Line Items]      
Cost   $ 1,273 $ 1,222
Accumulated depreciation   515 482
Net book value   $ 758 $ 740
Estimated useful life   17 years 17 years
Technology and other      
Property, Plant and Equipment [Line Items]      
Cost   $ 1,390 $ 1,431
Accumulated depreciation   624 640
Net book value   $ 766 $ 791
Estimated useful life   12 years 12 years
Construction in progress      
Property, Plant and Equipment [Line Items]      
Cost   $ 1,305 $ 1,169
Net book value   $ 1,305 $ 1,169
Chassis assets | Other Expense      
Property, Plant and Equipment [Line Items]      
Gain recognized in other expense $ 46