Note 11 - Properties (Details Textual) $ in Millions |
3 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
|
Dec. 31, 2020
USD ($)
|
Dec. 31, 2021
USD ($)
|
Dec. 31, 2020
USD ($)
|
Dec. 31, 2019
USD ($)
|
|
| Number of Depreciable Asset Classes | 60 | |||
| Cost of Property Repairs and Maintenance | $ 2,100 | $ 2,000 | $ 2,300 | |
| Brazos Yard [Member] | Other Expense [Member] | ||||
| Asset Impairment Charges, Total | $ 278 | |||
| Railroad Transportation Equipment [Member] | ||||
| Term of Depreciation Studies (Year) | 3 years | |||
| Railroad Transportation Track Assets [Member] | ||||
| Term of Depreciation Studies (Year) | 6 years | |||