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Noncontrolling Interests in Subsidiaries (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	$ 134,585		$ 134,585		$ 135,376
Net Income (Loss)	(29,085)	$ (50,933)	(18,429)	$ (71,457)
Net Income (Loss) Attributable to Noncontrolling Interest	3,723	$ 4,226	10,296	10,888
Inland River Services [Member] \| Other Inland River Services Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	$ 963		$ 963		980
Shipping Services [Member] \| Sea-Vista [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	49.00%		49.00%
Noncontrolling interests in subsidiaries	$ 118,798		$ 118,798		106,054
Assets, Net	$ 242,400		242,400
Net Income (Loss)			26,000	21,700
Net Income (Loss) Attributable to Noncontrolling Interest			$ 12,700	$ 10,600
Discontinued Operations [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	1.80%		1.80%
Noncontrolling interests in subsidiaries	$ 14,673		$ 14,673		28,190
Other Segments [Member] \| Other Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	$ 151		$ 151		$ 152
Minimum [Member] \| Inland River Services [Member] \| Other Inland River Services Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	3.00%		3.00%
Minimum [Member] \| Other Segments [Member] \| Other Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [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 Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	51.80%		51.80%
Maximum [Member] \| Discontinued Operations [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	50.00%		50.00%
Maximum [Member] \| Other Segments [Member] \| Other Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	14.60%		14.60%