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v3.25.3

Properties (Details) - USD ($) $ in Millions | 3 Months Ended |  |
--- | --- | --- | ---
Jun. 30, 2024 | Sep. 30, 2025 | Dec. 31, 2024
Property, Plant and Equipment [Line Items] |  |  |
Cost |  | $ 85,848 | $ 83,840
Accumulated depreciation |  | 26,456 | 25,497
Net book value |  | 59,392 | 58,343
Land |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Cost |  | 5,455 | 5,441
Net book value |  | 5,455 | 5,441
Total road |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Cost |  | 63,348 | 62,049
Accumulated depreciation |  | 20,388 | 19,614
Net book value |  | 42,960 | 42,435
Rail and other track material |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Cost |  | 19,646 | 19,283
Accumulated depreciation |  | 7,858 | 7,642
Net book value |  | $ 11,788 | $ 11,641
Estimated useful life |  | 45 years | 46 years
Ties |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Cost |  | $ 12,699 | $ 12,358
Accumulated depreciation |  | 4,251 | 4,109
Net book value |  | $ 8,448 | $ 8,249
Estimated useful life |  | 34 years | 34 years
Ballast |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Cost |  | $ 6,618 | $ 6,495
Accumulated depreciation |  | 2,274 | 2,182
Net book value |  | $ 4,344 | $ 4,313
Estimated useful life |  | 34 years | 34 years
Other roadway |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Cost |  | $ 24,385 | $ 23,913
Accumulated depreciation |  | 6,005 | 5,681
Net book value |  | $ 18,380 | $ 18,232
Estimated useful life |  | 47 years | 47 years
Total equipment |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Cost |  | $ 14,249 | $ 13,750
Accumulated depreciation |  | 5,431 | 5,243
Net book value |  | 8,818 | 8,507
Locomotives |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Cost |  | 9,899 | 9,517
Accumulated depreciation |  | 3,819 | 3,724
Net book value |  | $ 6,080 | $ 5,793
Estimated useful life |  | 18 years | 18 years
Freight cars |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Cost |  | $ 3,063 | $ 3,011
Accumulated depreciation |  | 1,088 | 1,037
Net book value |  | $ 1,975 | $ 1,974
Estimated useful life |  | 23 years | 22 years
Work equipment and other |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Cost |  | $ 1,287 | $ 1,222
Accumulated depreciation |  | 524 | 482
Net book value |  | $ 763 | $ 740
Estimated useful life |  | 17 years | 17 years
Technology and other |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Cost |  | $ 1,386 | $ 1,431
Accumulated depreciation |  | 637 | 640
Net book value |  | $ 749 | $ 791
Estimated useful life |  | 12 years | 12 years
Construction in progress |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Cost |  | $ 1,410 | $ 1,169
Net book value |  | $ 1,410 | $ 1,169
Chassis assets | Other Expense |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Gain recognized in other expense | $ 46 |  |

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