Quarterly report pursuant to Section 13 or 15(d)

Operating Leases (Details)

v3.20.1
Operating Leases (Details)
3 Months Ended
Mar. 31, 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 30
Petroleum and Chemical Carriers - U.S.-flag | Maximum  
Operating Leases [Line Items]  
Sale Leaseback Transaction, Lease Terms 77
U.S.-flag - Harbor Tugs  
Operating Leases [Line Items]  
Equipment Subject to Operating Lease, Number of Units 4
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 1 month
Other Equipment | Maximum  
Operating Leases [Line Items]  
Lessee, Operating Lease, Term of Contract 192 months