Annual report pursuant to Section 13 and 15(d)

Noncontrolling Interests in Subsidiaries (Details)

v3.8.0.1
Noncontrolling Interests in Subsidiaries (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Noncontrolling Interest [Line Items]                      
Noncontrolling interests in subsidiaries $ 129,678       $ 135,376       $ 129,678 $ 135,376  
Net Income (Loss) 79,521 $ 10,177 $ (456) $ 16,104 (33,877) $ (8,634) $ (23,764) $ (10,276) 81,709 (195,772) $ (59,850)
Net Income (Loss) Attributable to Noncontrolling Interest                 20,066 20,125 8,932
Inland River Services [Member] | Other Inland River Services Noncontrolling Interests [Member]                      
Noncontrolling Interest [Line Items]                      
Noncontrolling interests in subsidiaries 977       980       977 980  
Shipping Services [Member] | Sea-Vista [Member]                      
Noncontrolling Interest [Line Items]                      
Noncontrolling interests in subsidiaries 128,550       106,054       128,550 106,054  
Net Assets $ 262,300       216,400       262,300 216,400  
Net Income (Loss)                 45,900 36,300 5,200
Net Income (Loss) Attributable to Noncontrolling Interest                 $ 22,500 17,800 $ 2,600
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners 49.00%               49.00%    
Other Segments [Member] | Other Noncontrolling Interests [Member]                      
Noncontrolling Interest [Line Items]                      
Noncontrolling interests in subsidiaries $ 151       $ 152       $ 151 $ 152  
Minimum [Member] | Inland River Services [Member] | Other Inland River Services Noncontrolling Interests [Member]                      
Noncontrolling Interest [Line Items]                      
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners 3.00%               3.00%    
Minimum [Member] | Other Segments [Member] | Other Noncontrolling Interests [Member]                      
Noncontrolling Interest [Line Items]                      
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners 5.00%               5.00%    
Maximum [Member] | Inland River Services [Member] | Other Inland River Services Noncontrolling Interests [Member]                      
Noncontrolling Interest [Line Items]                      
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners 51.80%               51.80%