Goodwill, Other Intangible Assets, And Deferred Charges (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended			9 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2014
Goodwill And Other Intangible Assets [Line Items]
Definite Life Intangibles, Amortization		$ 3,714,000	$ 5,701,000	$ 3,055,000
Amortization expense for deferred charges - drydock		18,400,000	10,600,000	6,600,000
Amortization expense for deferred charges - financing		447,000	953,000	1,400,000
Increase (decrease) in amortization expense	(402,000)
Increase to earnings per share		$ 0.06
Increase (decrease) in future annual amortization expense		$ (1,600,000)
United Ocean Services, LLC [Member]
Goodwill And Other Intangible Assets [Line Items]
Intangible assets, useful life	12 years				8 years
Favorable Lease [Member] | United Ocean Services, LLC [Member]
Goodwill And Other Intangible Assets [Line Items]
Intangible assets, useful life		13 months	13 months