XML 106 R81.htm IDEA: XBRL DOCUMENT v3.24.0.1
Note 11 - Properties (Details Textual)
$ in Billions
12 Months Ended
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Dec. 31, 2021
USD ($)
Number of Depreciable Asset Classes 60    
Cost of Property Repairs and Maintenance $ 2.5 $ 2.4 $ 2.1
Railroad Transportation Equipment [Member]      
Term of Depreciation Studies (Year) 3 years    
Railroad Transportation Track Assets [Member]      
Term of Depreciation Studies (Year) 6 years