Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation and Accounting Policies - Property and Equipment (Details)

v3.19.1
Basis of Presentation and Accounting Policies - Property and Equipment (Details)
$ in Millions
3 Months Ended
Mar. 31, 2019
USD ($)
Property, Plant and Equipment [Line Items]  
Construction in progress $ 9.6
Petroleum and chemical carriers - U.S.-flag  
Property, Plant and Equipment [Line Items]  
Useful life 25 years
Bulk carriers - U.S.-flag  
Property, Plant and Equipment [Line Items]  
Useful life 25 years
Harbor and offshore tugs  
Property, Plant and Equipment [Line Items]  
Useful life 25 years
Ocean liquid tank barges  
Property, Plant and Equipment [Line Items]  
Useful life 25 years
Short-sea container/RORO vessels  
Property, Plant and Equipment [Line Items]  
Useful life 20 years
Inland river dry-cargo and specialty barges  
Property, Plant and Equipment [Line Items]  
Useful life 20 years
Inland river liquid tank barges  
Property, Plant and Equipment [Line Items]  
Useful life 25 years
Inland river towboats and harbor boats  
Property, Plant and Equipment [Line Items]  
Useful life 25 years
Terminal and fleeting facilities  
Property, Plant and Equipment [Line Items]  
Useful life 20 years