Operating Segments (Reconciliation Of The Totals Reported For The Operating Segments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Operating Segments [Abstract]
Total Revenues	$ 76,752		$ 74,897		$ 149,446		$ 156,021
Voyage Expenses	63,325	[1]	61,508	[1]	125,957	[1]	131,099	[1]
Gross Voyage Profit	13,347		13,314		23,301		24,577
Vessel Depreciation	6,517		5,804		13,238		11,575
Other Depreciation	18		11		36		34
Gross Profit	6,812		7,499		10,027		12,968
Administrative and General Expenses	5,232		6,170		10,811		11,603
Less: Net Loss of Unconsolidated Entities	(80)		(75)		(188)		(345)
Total Other Operating Expenses	5,152		6,095		10,623		11,258
Operating Income (Loss)	$ 1,660		$ 1,404		$ (596)		$ 1,710

[1] Includes Intangible Amortization