Quarterly report pursuant to Section 13 or 15(d)

Operating Leases (Details)

v3.20.2
Operating Leases (Details)
6 Months Ended
Jun. 30, 2020
Jun. 30, 2020
equipment
Petroleum and Chemical Carriers - U.S.-flag    
Operating Leases [Line Items]    
Equipment Subject to Operating Lease, Number of Units   2
Petroleum and Chemical Carriers - U.S.-flag | Minimum    
Operating Leases [Line Items]    
Sale Leaseback Transaction, Lease Terms 27  
Petroleum and Chemical Carriers - U.S.-flag | Maximum    
Operating Leases [Line Items]    
Sale Leaseback Transaction, Lease Terms 74  
U.S.-flag - Harbor Tugs    
Operating Leases [Line Items]    
Equipment Subject to Operating Lease, Number of Units   4
U.S.-flag Offshore Tug    
Operating Leases [Line Items]    
Equipment Subject to Operating Lease, Number of Units   1
Pure Car/Truck Carriers - U.S.-flag    
Operating Leases [Line Items]    
Equipment Subject to Operating Lease, Number of Units   4
Inland River Dry-Cargo Barges    
Operating Leases [Line Items]    
Equipment Subject to Operating Lease, Number of Units   50
Inland River Towboats    
Operating Leases [Line Items]    
Equipment Subject to Operating Lease, Number of Units   4
Inland River Harbor Boats    
Operating Leases [Line Items]    
Equipment Subject to Operating Lease, Number of Units   6
Other Equipment | Minimum    
Operating Leases [Line Items]    
Lessee, Operating Lease, Term of Contract 3 months 3 months
Other Equipment | Maximum    
Operating Leases [Line Items]    
Lessee, Operating Lease, Term of Contract 189 months 189 months