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
	Mar. 31, 2015	Mar. 31, 2014
Goodwill And Other Intangible Assets [Line Items]
Goodwill, Beginning Balance	$ 2,735
Goodwill, Ending Balance	2,735
Total Indefinite Life Intangibles, Beginning Balance	2,735
Total Indefinite Life Intangibles, Ending Balance	2,735
Definite Life Intangibles, Beginning Balance	25,042
Definite Life Intangibles, Amortization	(626)	(1,029)
Definite Life Intangibles, Ending Balance	24,416
Drydocking Costs, Beginning Balance	25,238
Drydocking Costs, Cash Additions	5,515
Drydocking Costs, Amortization	(4,560)
Drydocking Costs, Non-Cash Reclassifications	(831)
Drydocking Costs, Ending Balance	25,362
Financing Charges and Other, Beginning Balance	3,419
Financing Charges and Other, Cash Additions	28
Financing Charges and Other, Disposals	(95)
Financing Charges and Other, Amortization	(280)
Financing Charges and Other, Non-Cash Reclassifications	526
Financing Charges and Other, Ending Balance	3,598
Total Deferred Charges, Beginning Balance	28,657
Total Deferred Charges, Cash Additions	5,543
Total Deferred Charges, Disposals	(95)
Total Deferred Charges, Amortization	(4,840)
Total Deferred Charges, Non-Cash Reclassifications	(305)
Total Deferred Charges, Ending Balance	28,960
Trade Names [Member] | Frascati Shops, Inc. And Tower, LLC [Member]
Goodwill And Other Intangible Assets [Line Items]
Amortization period	240 months
Definite Life Intangibles, Beginning Balance	57
Definite Life Intangibles, Amortization	(1)
Definite Life Intangibles, Ending Balance	56
Trade Names [Member] | United Ocean Services, LLC [Member]
Goodwill And Other Intangible Assets [Line Items]
Amortization period	144 months
Definite Life Intangibles, Beginning Balance	1,357
Definite Life Intangibles, Amortization	(34)
Definite Life Intangibles, Ending Balance	1,323
Customer Relationships [Member] | Frascati Shops, Inc. And Tower, LLC [Member]
Goodwill And Other Intangible Assets [Line Items]
Amortization period	240 months
Definite Life Intangibles, Beginning Balance	375
Definite Life Intangibles, Amortization	(5)
Definite Life Intangibles, Ending Balance	370
Customer Relationships [Member] | United Ocean Services, LLC [Member]
Goodwill And Other Intangible Assets [Line Items]
Amortization period	144 months
Definite Life Intangibles, Beginning Balance	23,253
Definite Life Intangibles, Amortization	(586)
Definite Life Intangibles, Ending Balance	$ 22,667