Goodwill, Other Intangible Assets, And Deferred Charges (Schedule Of Goodwill, Other Intangible Assets, And Deferred Charges) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Aug. 06, 2012		Nov. 30, 2012
Goodwill And Other Intangible Assets [Line Items]
Goodwill, Gross	2,735		$ 2,735	$ 2,735
Goodwill, Net	2,735		2,735	2,735
Total Indefinite Life Intangibles, Gross Carrying Amount	2,735		2,735	2,735
Total Indefinite Life Intangibles, Net Carrying Amount	2,735		2,735	2,735
Definite Life Intangibles, Gross Carrying Amount	45,621		45,621	50,772
Definite Life Intangibles, Amortization	(9,252)		(9,252)	(10,689)
Definite Life Intangibles, Reclassified	(11,327)		(11,327)	(11,327)
Definite Life Intangibles, Net Carrying Amount	25,042		25,042	28,756
Drydocking Costs, Gross	55,314		55,314	46,667
Drydocking Costs, Amortization	(29,160)		(29,160)	(18,394)
Drydocking Costs, Reclassified	(916)		(916)	(1,845)
Drydocking Costs, Net Carrying Amount	25,238		25,238	26,428
Financing Charges and Other, Gross	4,906		4,906	3,921
Financing Charges and Other, Amortization	(1,487)		(1,487)	(1,040)
Financing Charges and Other, Net Carrying Amount	3,419		3,419	2,881
Deferred Assets, Gross	60,220		60,220	50,588
Deferred Assets, Accumulated Amortization	(30,647)		(30,647)	(19,434)
Deferred Assets, Reclassified	(916)		(916)	(1,845)
Deferred Assets, Net Carrying Amount	28,657		28,657	29,309
Frascati Shops, Inc. And Tower, LLC [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill, Net					828	[1]
United Ocean Services, LLC [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill, Net							1,907	[2]
Amortization period	12 years	8 years
Trade Names [Member] | Frascati Shops, Inc. And Tower, LLC [Member]
Goodwill And Other Intangible Assets [Line Items]
Amortization period			240 months	240 months
Definite Life Intangibles, Gross Carrying Amount	65		65	65
Definite Life Intangibles, Amortization	(8)		(8)	(5)
Definite Life Intangibles, Net Carrying Amount	57		57	60
Trade Names [Member] | United Ocean Services, LLC [Member]
Goodwill And Other Intangible Assets [Line Items]
Amortization period			144 months	96 months
Definite Life Intangibles, Gross Carrying Amount	1,805		1,805	1,805
Definite Life Intangibles, Amortization	(448)		(448)	(244)
Definite Life Intangibles, Net Carrying Amount	1,357		1,357	1,561
Customer Relationships [Member] | Frascati Shops, Inc. And Tower, LLC [Member]
Goodwill And Other Intangible Assets [Line Items]
Amortization period			240 months	240 months
Definite Life Intangibles, Gross Carrying Amount	425		425	425
Definite Life Intangibles, Amortization	(50)		(50)	(29)
Definite Life Intangibles, Net Carrying Amount	375		375	396
Customer Relationships [Member] | United Ocean Services, LLC [Member]
Goodwill And Other Intangible Assets [Line Items]
Amortization period			144 months	96 months
Definite Life Intangibles, Gross Carrying Amount	30,927		30,927	30,927
Definite Life Intangibles, Amortization	(7,674)		(7,674)	(4,188)
Definite Life Intangibles, Net Carrying Amount	23,253		23,253	26,739
Favorable Lease [Member] | United Ocean Services, LLC [Member]
Goodwill And Other Intangible Assets [Line Items]
Amortization period			13 months	13 months
Definite Life Intangibles, Gross Carrying Amount	1,072		1,072	1,072
Definite Life Intangibles, Amortization	(1,072)		(1,072)	(1,072)
Favorable Lease [Member] | UOS EBO Acquisition [Member]
Goodwill And Other Intangible Assets [Line Items]
Definite Life Intangibles, Gross Carrying Amount	11,327		11,327	11,327
Definite Life Intangibles, Reclassified	(11,327)		(11,327)	(11,327)
Favorable Charter [Member] | Dry Bulk Cape Holding Inc. [Member]
Goodwill And Other Intangible Assets [Line Items]
Amortization period				24 months
Definite Life Intangibles, Gross Carrying Amount				5,151
Definite Life Intangibles, Amortization				$ (5,151)

[1] Goodwill represents the sum of the consideration transferred and the net liabilities assumed and represents the future economic benefits arising from other assets acquired that could not be individually identified and separately recognized. Our above-described goodwill is not amortized nor do we expect it to be deductible for tax purposes. Specifically, the goodwill recorded as part of the acquisition of the Acquired Companies includes the following: the expected synergies and other benefits that we believe will result from combining the operations of the Acquired Companies with our existing Rail-Ferry operations,any intangible assets that do not qualify for separate recognition, including an assembled workforce of the acquired companies, andthe anticipated higher rate of return of the Acquired Companies existing businesses as going concerns compared to the anticipated rate of return if we had acquired all of the net assets separately.

[2] Goodwill represents the fair value of the consideration transferred over the net assets acquired and represents the future economic benefits arising from other assets acquired that could not be individually identified and separately recognized.  Our above-described goodwill is not amortized nor do we expect it to be deductible for tax purposes.  Specifically, the goodwill recorded as part of the acquisition of UOS includes the following:the expected synergies and other benefits that we believe will result from combining the operations of UOS with our existing Jones Act operations,any intangible assets that do not qualify for separate recognition, including an assembled workforce of the acquired companies, andthe anticipated higher rate of return of UOS’s existing businesses as going concerns compared to the anticipated rate of return if we had acquired all of the net assets separately.