Annual report pursuant to Section 13 and 15(d)

Investments, At Equity, And Advances To 50% Or Less Owned Companies (Narrative) (Details)

v3.8.0.1
Investments, At Equity, And Advances To 50% Or Less Owned Companies (Narrative) (Details)
$ in Thousands
9 Months Ended 12 Months Ended
Sep. 30, 2017
USD ($)
Dec. 31, 2017
USD ($)
equipment
Dec. 31, 2016
USD ($)
equipment
Dec. 31, 2015
USD ($)
equipment
Dec. 31, 2014
USD ($)
Jun. 30, 2017
Dec. 02, 2016
Nov. 30, 2016
USD ($)
Jun. 01, 2015
Schedule of Equity Method Investments [Line Items]                  
Cumulative undistributed net earnings of 50% or less owned companies accounted for by the equity method included in the Company's consolidated retained earnings   $ (40,100) $ (35,000)            
Proceeds from Issuance of Secured Debt     8,000 $ 1,700          
Proceeds on the sale of a controlling interest in a subsidiary   5,000 0 0          
Letters of Credit Outstanding, Amount $ 27,200                
Proceeds from Equity Method Investment, Distribution   15,568 9,519 46,306          
Asset Impairment Charges   400 1,100            
Trailer Bridge Inc [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Repayments of Advances       (18,700)          
Related Party Transaction, Revenues from Transactions with Related Party     $ 300 800          
Equity Method Investment, Ownership Percentage     55.30%            
Payments for Advance to Affiliate   2,000 $ 1,700            
Proceeds from Collection of Advance to Affiliate   (6,000)              
Business Combination, Separately Recognized Transactions, Net Gains and Losses     (2,200)            
RF Vessel Holdings [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Proceeds on the sale of a controlling interest in a subsidiary   $ 1,900              
Equity Method Investment, Ownership Percentage   50.00%              
Golfo de Mexico [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Related Party Transaction, Revenues from Transactions with Related Party   $ 300              
Proceeds on the sale of a controlling interest in a subsidiary   3,100              
Equity Method Investment, Ownership Percentage           50.00%      
Proceeds from Equity Method Investment, Distribution, Return of Capital   300              
KSM [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Partners' Capital Account, Contributions $ 300                
Related Party Transaction, Revenues from Transactions with Related Party   300              
Equity Method Investment, Ownership Percentage 50.00%                
SeaJon                  
Schedule of Equity Method Investments [Line Items]                  
Proceeds from Equity Method Investment, Distribution, Return of Capital   3,500 600 600          
Proceeds from Equity Method Investment, Distribution   12,500              
Sea-Access [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Related Party Transaction, Revenues from Transactions with Related Party     500 1,000          
Proceeds from Equity Method Investment, Distribution, Return of Capital     2,000 4,400          
Partners' Capital Account, Return of Capital     8,400 8,300          
SeaJon II [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Partners' Capital Account, Contributions       1,000          
Related Party Transaction, Revenues from Transactions with Related Party     100 100          
Partners' Capital Account, Return of Capital       300          
Business Combination, Separately Recognized Transactions, Net Gains and Losses     1,900            
SCFCo Holdings                  
Schedule of Equity Method Investments [Line Items]                  
Partners' Capital Account, Contributions   400   800 $ 18,000        
Repayments of Advances       (14,000)          
Related Party Transaction, Revenues from Transactions with Related Party   100 100 200          
Equity Method Investment, Other than Temporary Impairment     7,700 21,500          
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity   26,500              
Payments for Advance to Affiliate   2,500 1,800            
Proceeds from Collection of Advance to Affiliate   (1,700)              
Asset Impairment Charges       21,500          
Advanced to joint ventures   30,300              
Bunge-SCF Grain [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Repayments of Advances       (2,000)          
Related Party Transaction, Revenues from Transactions with Related Party   1,100 1,000 1,000          
Related party transaction expense   7,200 7,200 10,800          
Advanced to joint ventures   7,000              
SCF Bunge Marine [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Related Party Transaction, Revenues from Transactions with Related Party   38,700 35,000 41,700          
Related party transaction expense   41,400 40,200 47,900          
Proceeds from Equity Method Investment, Distribution, Return of Capital   100 2,500 4,000          
Witt O'Brien's do Brazil [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Proceeds from Equity Method Investment, Distribution, Return of Capital   100 100 100          
Dorian LPG [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Business Combination, Separately Recognized Transactions, Net Gains and Losses       32,300          
Hawker Pacific Airservices Limited [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Related Party Transaction, Revenues from Transactions with Related Party   300 300 300          
Letters of Credit Outstanding, Amount   6,500              
VA&E [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Partners' Capital Account, Contributions       3,500          
Repayments of Advances     $ (1,100)            
Equity Method Investment, Other than Temporary Impairment $ 900                
Equity Method Investment, Ownership Percentage     41.30%           81.10%
Advanced to joint ventures   7,600              
Line of Credit Facility, Maximum Borrowing Capacity     $ 3,500         $ 6,000  
Proceeds from Unsecured Lines of Credit   3,500 10,000 15,000          
Repayments of Long-term Lines of Credit     12,400 11,500          
Avion Pacific Limited [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Repayments of Advances       (3,000)          
Payments for Advance to Affiliate   1,000 3,000            
Proceeds from Collection of Advance to Affiliate   (4,000)              
Cleancor [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Payments for Advance to Affiliate       2,000          
Advanced to joint ventures   1,900              
Other Corporate Joint Ventures [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Partners' Capital Account, Contributions     $ 800 $ 200          
Proceeds from Collection of Advance to Affiliate   (400)              
Advanced to joint ventures   $ 2,400              
Inland River Towboats [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Number Of Equipments Acquired | equipment   3 2 9          
Inland River Dry Cargo Barges [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Number Of Equipments Acquired | equipment   0 46 0          
U.S.-flag Harbor Tugs [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Number Of Equipments Acquired | equipment   1 1 0          
U.S.-flag Harbor Tugs [Member] | Trailer Bridge Inc [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Related Party Transaction, Revenues from Transactions with Related Party   $ 3,100 $ 3,000 $ 400          
SeaJon II [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Business Acquisition, Percentage of Voting Interests Acquired             50.00%    
Payments to Acquire Businesses, Gross     3,400            
SeaJon II [Member] | U.S.-flag Harbor Tugs [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Number Of Equipments Acquired | equipment   1              
Subordinated Debt [Member] | VA&E [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Advanced to joint ventures $ 3,500   $ 3,500 $ 1,000          
Long-term Debt [Member] | VA&E [Member]                  
Schedule of Equity Method Investments [Line Items]                  
Advanced to joint ventures               $ 1,100