Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation and Accounting Policy Property and Equipment (Details)

v3.2.0.727
Basis of Presentation and Accounting Policy Property and Equipment (Details) - USD ($)
$ in Millions
6 Months Ended 12 Months Ended
Jun. 30, 2015
Dec. 31, 2014
Property, Plant and Equipment [Line Items]    
Capitalized Interest Costs, Including Allowance for Funds Used During Construction   $ 9.6
Offshore Support Vessels [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 20 years  
Wind Farm Utility Vessel [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 10 years  
Inland River Dry Cargo Barges [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 20 years  
Inland River Liquid Tank Barges [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 25 years  
Inland River Towboats [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 25 years  
U.S.-flag Product Tankers [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 25 years  
R O R O Vessels [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 20 years  
Harbor and Offshore Tugs [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 25 years  
Ocean Liquid Tank Barge [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 25 years  
Terminal And Manufacturing Facilities [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Useful Life 20 years