Operating Segments (Reconciliation Of The Totals Reported For The Operating Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Operating Segments [Abstract]
Revenues	$ 67,308	$ 76,752	$ 135,334	$ 149,446
Voyage Expenses	53,809	57,802	106,020	115,235
Amortization Expense	4,348	5,486	9,535	10,649
Gross Voyage Profit	9,816	13,384	21,337	23,374
Vessel Depreciation	5,490	6,516	11,033	13,237
Other Depreciation	187	180	371	364
Gross Profit	4,139	6,688	9,933	9,773
Administrative and General Expenses	4,788	5,108	9,810	10,557
Impairment Loss	1,828		1,828
Gain on Sale of Other Assets	(4,747)		(4,679)
Less: Net Income (Loss) of Unconsolidated Entities	665	(80)	1,558	(188)
Total Other Operating Expenses	2,534	5,028	8,517	10,369
Operating Income (Loss)	$ 1,605	$ 1,660	$ 1,416	$ (596)