Summary Of Significant Accounting Policies (Narrative) (Details)			1 Months Ended	3 Months Ended	12 Months Ended
		Feb. 29, 2016 item	Jan. 31, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($) item $ / shares	Dec. 31, 2015 USD ($) item $ / shares		Dec. 31, 2014 USD ($) $ / shares	Oct. 21, 2015 segment
Summary Of Significant Accounting Policies [Line Items]
Number of core segments approved for restructuring | segment								3
Current maturities of long-term debt, net				$ 156,807,000	$ 156,807,000		$ 23,367,000
Allowance for doubtful accounts				587,000	587,000		78,000
Net cash proceeds from sales					$ 31,025,000		1,659,000
Number of vessels held for sale from forty-seven vessels in fleet | item					23
Debt issuance costs					$ 3,000,000		2,900,000
Loss on Extinguishment of Debt					$ (585,000)		(225,000)
Minimum percentage of ownership considered for consolidation (in hundredths)					50.00%
Minimum percentage of ownership considered for equity method of accounting for investments (in hundredths)					20.00%
Maximum percentage of ownership considered for equity method of accounting for investments (in hundredths)					50.00%
Number of vessels qualified under MSP program | item					8
Revenues					$ 259,474,000		294,834,000
Deferred tax asset				25,118,000	25,118,000		17,879,000
Inventory				7,035,000	7,035,000		9,760,000
Capitalized interest					54,000		120,000
Depreciation expense					23,002,000		26,984,000
Impairment charge					154,463,000		38,213,000
Impairment charges of assets held for sale					(154,463,000)		(38,213,000)
Goodwill impairment loss				$ 800,000	$ (2,735,000)
Goodwill							2,735,000
Loss on foreign currency transaction					$ (800,000)		(700,000)
Non-cash foreign exchange loss					$ (100,000)		$ (200,000)
Impairment of definite-life intangibles				$ 400,000
Preferred stock, stated liquidation preference (in dollars per share) | $ / shares				$ 100.00	$ 100.00		$ 100.00
Change in liability from effect of the adjustment to the pension funded status					$ 1,800,000
Change in OCI from effect of the adjustment to the pension funded status					900,000
Pension plan, underfunded amount				$ 1,400,000	$ 1,400,000
Number of vessels in fleet | item				47	47
Deferred tax asset on unrecognized tax benefits related to restricted stock units				$ 312,000	$ 312,000
Preferred Stock Dividends Not Paid For Two Periods [Member] | Subsequent Event [Member]
Summary Of Significant Accounting Policies [Line Items]
Increase in preferred stock dividend rate percentage			2.00%
Preferred stock liquidation preference value			$ 100.00
Preferred stock, stated liquidation preference (in dollars per share) | $ / shares			$ 2.00
Restricted Stock Unit Adjustments [Member] | Federal [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred tax asset on unrecognized tax benefits related to restricted stock units				300,000	300,000
Increase (decrease) to net operating loss				$ 700,000
Scenario, Adjustment [Member]
Summary Of Significant Accounting Policies [Line Items]
Related debt paid off					13,500,000
Deferred Gain (Loss) on Early Extinguishment of Debt [Member]
Summary Of Significant Accounting Policies [Line Items]
Loss on Extinguishment of Debt					$ 200,000
Deferred Drydocking Cost [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization period					5 years
Deferred Drydocking Cost [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization period					2 years
Container Vessels [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of vessels delivered | item				2	2
Pure Car Truck Carriers [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of vessels and units subject to divestitures | item				1
Number of vessels sold | item					1
Chemical Tankers [Member] | Subsequent Event [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage ownership investment sold		30.00%
Number of properties with thirty percent investment sold | item		2
Capesize Vessel [Member] | Subsequent Event [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of vessels sold | item		1
Asphalt Tankers [Member] | Subsequent Event [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage ownership investment sold		30.00%
Number of properties with thirty percent investment sold | item		2
ATB Barge And Tug Units [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment charges of assets held for sale	[1]						$ 6,584,000
Handysize Bulk Carriers [Member] | Subsequent Event [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of vessels sold | item		2
Tug-Barge Unit [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of vessels and units subject to divestitures | item				1
Ice Strengthened Multi-Purpose Vessel [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment charge					$ 10,500,000
Leasehold Improvements [Member] | Mobile, Alabama Corporate Office Lease [Member]
Summary Of Significant Accounting Policies [Line Items]
Depreciation expense					900,000
Pension Plan [Member]
Summary Of Significant Accounting Policies [Line Items]
Pension plan, underfunded amount				$ 1,400,000	1,400,000
Postretirement Benefits [Member]
Summary Of Significant Accounting Policies [Line Items]
Pension plan, underfunded amount				9,900,000	$ 9,900,000
MSP [Member] | Pure Car Truck Carriers [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of vessels sold | item					1
Frascati Shops, Inc. and Tower, LLC [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment charges of assets held for sale					$ 94,300,000
Goodwill impairment loss				800,000	828,000	[2]
Impairment of definite-life intangibles	[3]				(411,000)
United Ocean Services, LLC [Member]
Summary Of Significant Accounting Policies [Line Items]
Goodwill impairment loss					1,900,000
Impairment of definite-life intangibles				$ 22,100,000	(22,129,000)	[4]
United Ocean Services, LLC [Member] | Uos Vessels [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment charge					22,700,000
PCTC And Specialty Contracts [Member] | MSP [Member]
Summary Of Significant Accounting Policies [Line Items]
Revenues					$ 22,900,000		$ 24,500,000

[1] The loss of $6.6 million is related to an ATB tug/barge unit, which was written down to its fair market value less costs to sell. The assets held for sale balance of $7.0 million consists of the ATB tug/barge unit of $6.4 million and $0.6 million of inventory associated with three handysize vessels that were held for sale.

[2] Refers to the goodwill associated with our FSI acquisition, which is held for sale.

[3] Refers to trade names and customer relations associated with our FSI acquisition, which is held for sale

[4] Refers to trade names and customer relations associated with our UOS acquisition included in the Jones Act segment.