Operating Segments (Details) (USD $)	3 Months Ended					6 Months Ended
	Jun. 30, 2012		Mar. 31, 2012	Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Segment Reporting Information [Line Items]
Number of operating segments						5
Segment Profit and Loss [Abstract]
Revenue from External Customers	$ 60,320,000			$ 69,961,000		$ 125,524,000		$ 134,295,000
Intersegment Revenues (Eliminated)	(5,250,000)			(5,554,000)		(10,311,000)		(9,331,000)
Intersegment Expenses (Eliminated)	5,250,000			5,554,000		10,311,000		9,331,000
Voyage Expenses (Income)	47,026,000			51,814,000		97,852,000		100,804,000
Add back [Abstract]
Operating Lease Expense	1,810,000			4,153,000		3,172,000		7,662,000
Direct Finance Lease Amortization	760,000			1,380,000		2,279,000		2,711,000
Gross Voyage Profit *	15,864,000	[1]		23,680,000	[1]	33,123,000	[1]	43,864,000	[1]
Gross Voyage Profit percentage (in hundredths)	26.00%			34.00%		26.00%		33.00%
Less [Abstract]
Operating Lease Expense	1,810,000			4,153,000		3,172,000		7,662,000
Direct Finance Lease Amortization	760,000			1,380,000		2,279,000		2,711,000
Vessel Depreciation	5,723,000			6,095,000		12,080,000		11,469,000
Gross Profit (Loss)	7,571,000	[1]		12,052,000	[1]	15,592,000	[1]	22,022,000	[1]
Interest Expense	2,281,000			2,330,000		5,008,000		4,620,000
Segment Profit (Loss)	5,290,000			9,722,000		10,584,000		17,402,000
Reconciliation of Profit (Loss) from Segments to Consolidated [Abstract]
Total Profit for Reportable Segments	5,290,000			9,722,000		10,584,000		17,402,000
Unallocated Amounts [Abstract]
Administrative and General Expenses	(4,720,000)			(5,455,000)		(10,228,000)		(11,284,000)
Gain on Sale/Purchase of Other Assets	667,000		3,799,000	0		4,466,000		0
Derivative Income (Loss)	(117,000)			(106,000)		32,000		15,000
Gain on Sale of Investment	24,000			114,000		66,000		114,000
Other Income from Vessel Financing	605,000			672,000		1,227,000		1,360,000
Investment Income	146,000			185,000		274,000		385,000
Foreign Exchange Gain (Loss)	(1,734,000)			(1,900,000)		1,914,000		(411,000)
Gain on Dry Bulk Transaction	0			130,000		0		18,844,000
Income Before Provision for Income Taxes and Equity in Net (Loss) Income of Unconsolidated Entities	161,000			3,362,000		8,335,000		26,425,000
Time Charter Contracts - U.S. Flag [Member]
Segment Profit and Loss [Abstract]
Revenue from External Customers	34,488,000			39,290,000		73,506,000		78,307,000
Intersegment Revenues (Eliminated)	0			0		0		0
Intersegment Expenses (Eliminated)	0			0		0		0
Voyage Expenses (Income)	27,858,000			29,952,000		58,952,000		59,951,000
Add back [Abstract]
Operating Lease Expense	900,000			1,060,000		1,364,000		2,119,000
Direct Finance Lease Amortization	760,000			662,000		1,499,000		1,305,000
Gross Voyage Profit *	8,290,000	[1]		11,060,000	[1]	17,417,000	[1]	21,780,000	[1]
Gross Voyage Profit percentage (in hundredths)	24.00%			28.00%		24.00%		28.00%
Less [Abstract]
Operating Lease Expense	900,000			1,060,000		1,364,000		2,119,000
Direct Finance Lease Amortization	760,000			662,000		1,499,000		1,305,000
Vessel Depreciation	2,310,000			2,495,000		4,876,000		5,004,000
Gross Profit (Loss)	4,320,000	[1]		6,843,000	[1]	9,678,000	[1]	13,352,000	[1]
Interest Expense	550,000			678,000		1,308,000		1,353,000
Segment Profit (Loss)	3,770,000			6,165,000		8,370,000		11,999,000
Reconciliation of Profit (Loss) from Segments to Consolidated [Abstract]
Total Profit for Reportable Segments	3,770,000			6,165,000		8,370,000		11,999,000
Time Charter Contracts - International Flag [Member]
Segment Profit and Loss [Abstract]
Revenue from External Customers	11,931,000			15,813,000		25,234,000		27,023,000
Intersegment Revenues (Eliminated)	0			0		0		0
Intersegment Expenses (Eliminated)	0			0		0		0
Voyage Expenses (Income)	7,252,000			8,294,000		14,394,000		15,179,000
Add back [Abstract]
Operating Lease Expense	0			2,195,000		0		3,746,000
Direct Finance Lease Amortization	0			718,000		780,000		1,406,000
Gross Voyage Profit *	4,679,000	[1]		10,432,000	[1]	11,620,000	[1]	16,996,000	[1]
Gross Voyage Profit percentage (in hundredths)	39.00%			66.00%		46.00%		63.00%
Less [Abstract]
Operating Lease Expense	0			2,195,000		0		3,746,000
Direct Finance Lease Amortization	0			718,000		780,000		1,406,000
Vessel Depreciation	2,702,000			2,699,000		5,792,000		4,689,000
Gross Profit (Loss)	1,977,000	[1]		4,820,000	[1]	5,048,000	[1]	7,155,000	[1]
Interest Expense	1,213,000			1,337,000		2,828,000		2,638,000
Segment Profit (Loss)	764,000			3,483,000		2,220,000		4,517,000
Reconciliation of Profit (Loss) from Segments to Consolidated [Abstract]
Total Profit for Reportable Segments	764,000			3,483,000		2,220,000		4,517,000
COA [Member]
Segment Profit and Loss [Abstract]
Revenue from External Customers	4,207,000			4,500,000		7,600,000		8,731,000
Intersegment Revenues (Eliminated)	0			0		0		0
Intersegment Expenses (Eliminated)	0			0		0		0
Voyage Expenses (Income)	4,081,000			4,601,000		8,367,000		8,912,000
Add back [Abstract]
Operating Lease Expense	910,000			898,000		1,808,000		1,797,000
Direct Finance Lease Amortization	0			0		0		0
Gross Voyage Profit *	1,036,000	[1]		797,000	[1]	1,041,000	[1]	1,616,000	[1]
Gross Voyage Profit percentage (in hundredths)	25.00%			18.00%		14.00%		19.00%
Less [Abstract]
Operating Lease Expense	910,000			898,000		1,808,000		1,797,000
Direct Finance Lease Amortization	0			0		0		0
Vessel Depreciation	0			0		0		0
Gross Profit (Loss)	126,000	[1]		(101,000)	[1]	(767,000)	[1]	(181,000)	[1]
Interest Expense	259,000			0		259,000		0
Segment Profit (Loss)	(133,000)			(101,000)		(1,026,000)		(181,000)
Reconciliation of Profit (Loss) from Segments to Consolidated [Abstract]
Total Profit for Reportable Segments	(133,000)			(101,000)		(1,026,000)		(181,000)
Rail-Ferry Service [Member]
Segment Profit and Loss [Abstract]
Revenue from External Customers	9,396,000			9,867,000		18,597,000		18,921,000
Intersegment Revenues (Eliminated)	0			0		0		0
Intersegment Expenses (Eliminated)	0			0		0		0
Voyage Expenses (Income)	7,948,000			8,807,000		16,316,000		16,438,000
Add back [Abstract]
Operating Lease Expense	0			0		0		0
Direct Finance Lease Amortization	0			0		0		0
Gross Voyage Profit *	1,448,000	[1]		1,060,000	[1]	2,281,000	[1]	2,483,000	[1]
Gross Voyage Profit percentage (in hundredths)	15.00%			11.00%		12.00%		13.00%
Less [Abstract]
Operating Lease Expense	0			0		0		0
Direct Finance Lease Amortization	0			0		0		0
Vessel Depreciation	701,000			899,000		1,399,000		1,771,000
Gross Profit (Loss)	747,000	[1]		161,000	[1]	882,000	[1]	712,000	[1]
Interest Expense	161,000			193,000		383,000		386,000
Segment Profit (Loss)	586,000			(32,000)		499,000		326,000
Reconciliation of Profit (Loss) from Segments to Consolidated [Abstract]
Total Profit for Reportable Segments	586,000			(32,000)		499,000		326,000
Other [Member]
Segment Profit and Loss [Abstract]
Revenue from External Customers	298,000			491,000		587,000		1,313,000
Intersegment Revenues (Eliminated)	(5,250,000)			(5,554,000)		(10,311,000)		(9,331,000)
Intersegment Expenses (Eliminated)	5,250,000			5,554,000		10,311,000		9,331,000
Voyage Expenses (Income)	(113,000)			160,000		(177,000)		324,000
Add back [Abstract]
Operating Lease Expense	0			0		0		0
Direct Finance Lease Amortization	0			0		0		0
Gross Voyage Profit *	411,000	[1]		331,000	[1]	764,000	[1]	989,000	[1]
Gross Voyage Profit percentage (in hundredths)	138.00%			67.00%		130.00%		75.00%
Less [Abstract]
Operating Lease Expense	0			0		0		0
Direct Finance Lease Amortization	0			0		0		0
Vessel Depreciation	10,000			2,000		13,000		5,000
Gross Profit (Loss)	401,000	[1]		329,000	[1]	751,000	[1]	984,000	[1]
Interest Expense	98,000			122,000		230,000		243,000
Segment Profit (Loss)	303,000			207,000		521,000		741,000
Reconciliation of Profit (Loss) from Segments to Consolidated [Abstract]
Total Profit for Reportable Segments	$ 303,000			$ 207,000		$ 521,000		$ 741,000

[1] Information used by Chief Decision Makers.