SIGNIFICANT OPERATIONS (Details) (USD $)	1 Months Ended	3 Months Ended										9 Months Ended	12 Months Ended
	Jan. 31, 2013	Dec. 31, 2012		Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011		Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Sep. 30, 2010	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009	Dec. 31, 2006
Segment Reporting Information [Line Items]
Number of vessels owned or operated																				2
Concentration risk percentage (in hundredths)													10.00%		10.00%		10.00%
Percentage of total work force (in hundredths)													72.00%
Summary of revenues attributable to the major geographic areas [Abstract]
Total Revenues		$ 56,810,000		$ 61,162,000	$ 60,320,000	$ 65,204,000	$ 61,814,000		$ 67,087,000	$ 69,961,000	$ 64,334,000		$ 243,496,000		$ 263,196,000		$ 290,049,000
Number of Pure Car Truck Carriers owned													4
Number of Pure Car Truck Carriers with Buy Back Options													3
Percentage of shareholders interest owned (in hundredths)	25.00%																25.00%		25.00%
Number Of Mini Bulk Carriers Acquired	4												14				2		8
Segment Profit and Loss [Abstract]
Revenue from External Customers													243,496,000		263,196,000		290,049,000
Intersegment Revenues (Eliminated)													18,638,000		17,419,000		18,642,000
Intersegment Expenses (Eliminated)													(18,638,000)		(17,419,000)		(18,642,000)
Voyage Expenses		45,262,000		45,394,000	47,026,000	50,826,000	44,367,000		46,911,000	51,814,000	48,990,000		188,508,000		192,082,000		209,347,000
Loss (Income) of Unconsolidated Entities													215,000		410,000		(9,282,000)
Gross Voyage Profit Margin Percentage (in hundredths)													22.00%		27.00%		31.00%
Vessel Depreciation and Other													24,398,000		25,388,000		17,929,000
Gross Profit													30,375,000		45,316,000		46,625,000
Impairment Loss												25,430,000	0		0		25,430,000
Gross Voyage Profit													54,773,000		70,704,000		89,984,000
Interest Expense													10,409,000		10,361,000		7,157,000
Segment Profit (Loss)													19,966,000		34,955,000		39,468,000
Segment Assets		492,798,000					529,151,000						492,798,000		529,151,000		399,060,000
Expenditures for Segment Assets													146,188,000		166,540,000		125,662,000
Reconciliation of profit (loss) from segments to consolidated [Abstract]
Total Profit for Reportable Segments													19,966,000		34,955,000		39,468,000
Unallocated Amounts [Abstract]
Administrative and General Expenses													(23,244,000)		(20,961,000)		(21,202,000)
Gain on Sale of Other Assets													16,625,000		0		42,000
Derivative Loss													(485,000)		(101,000)		(426,000)
Gain (Loss) on Sale of Investment													580,000		(747,000)		213,000
Investment Income													470,000		637,000		1,778,000
Other Income from Vessel Financing													2,387,000		2,653,000		2,335,000
Foreign Exchange Gain (Loss)													5,506,000		(3,051,000)		(8,196,000)
Gain on Dry Bulk Transaction													0		18,844,000		0
Benefit (Provision) for Income Taxes													157,000		(680,000)		1,290,000
Net Income		11,540,000		1,782,000	704,000	7,936,000	1,781,000		2,850,000	2,838,000	24,080,000		21,962,000		31,549,000		15,302,000
Unallocated Amounts [Abstract]
Current Assets		88,921,000					85,125,000						88,921,000		85,125,000
Investment in Unconsolidated Entities		12,676,000					12,800,000						12,676,000		12,800,000
Due from Related Parties		1,709,000					1,571,000						1,709,000		1,571,000
Goodwill		2,700,000					0						2,700,000		0
Other Assets		5,509,000					202,000						5,509,000		202,000
Notes Receivable		33,381,000					37,714,000						33,381,000		37,714,000
Total Assets		637,693,000					666,565,000						637,693,000		666,565,000
MSC [Member]
Segment Reporting Information [Line Items]
Revenue from major customer													3,618,000		26,495,000		34,401,000
United States
Summary of revenues attributable to the major geographic areas [Abstract]
Total Revenues													123,782,000		132,387,000		179,127,000
Asian Countries [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Total Revenues													63,860,000		86,342,000		84,146,000
Rail-Ferry Service Operating Between U.S. Gulf Coast and Mexico [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Total Revenues													32,479,000		36,422,000		26,768,000
South America [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Total Revenues													10,416,000
Other Countries [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Total Revenues													485,000		704,000		8,000
Europe [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Total Revenues													12,474,000		7,341,000		0
Roll On/Roll Off vessels [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Number of units													2
PCTC [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Number of units													7
PCTC [Member] | MSP [Member]
Segment Reporting Information [Line Items]
Revenue from major customer													17,946,000		17,541,000		17,169,000
Special Purpose vessels [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Number of units													2
Capesize Bulk Carrier [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Weight of diversified bulk carrier													170,578
Number of vessels which deployed													1
Mini-Bulk Carrier [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Weight of diversified bulk carrier													8,028
Percentage of shareholders interest owned (in hundredths)		25.00%											25.00%
Handysize Bulk Carriers [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Number of vessels which deployed													1
Time Charter Contracts - U.S. Flag [Member]
Segment Reporting Information [Line Items]
Revenue from major customer													37,365,000		32,766,000		31,256,000
Time Charter Contracts - U.S. Flag [Member] | MSP [Member]
Segment Reporting Information [Line Items]
Revenue from major customer													6,200,000		5,900,000		5,800,000
Time Charter Contracts - U.S. Flag [Member] | U S Government [Member]
Segment Reporting Information [Line Items]
Revenue from major customer													44,667,000		39,425,000		79,778,000
Time Charter Contracts - U.S. Flag [Member] | Roll On/Roll Off vessels [Member]
Segment Reporting Information [Line Items]
Number of vessels owned or operated		3											3
Time Charter Contracts - U.S. Flag [Member] | PCTC [Member]
Segment Reporting Information [Line Items]
Number of vessels owned or operated		6											6
Time Charter Contracts - U.S. Flag [Member] | Container vessels [Member]
Segment Reporting Information [Line Items]
Number of vessels owned or operated		2											2
Time Charter Contracts - International Flag [Member] | PCTC [Member]
Segment Reporting Information [Line Items]
Revenue from major customer													13,543,000		24,281,000		25,566,000
Number of vessels owned or operated		3											3
Rail-Ferry Service [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Number of units													2
Percentage of shareholders interest owned (in hundredths)		49.00%											49.00%
Segment Profit and Loss [Abstract]
Revenue from External Customers													33,335,000		36,422,000		26,673,000
Intersegment Expenses (Eliminated)													0		0		0
Voyage Expenses													29,522,000		30,664,000		22,649,000
Loss (Income) of Unconsolidated Entities													290,000		347,000		48,000
Gross Voyage Profit Margin Percentage (in hundredths)													11.00%		15.00%		15.00%
Vessel Depreciation and Other													2,861,000		3,642,000		5,181,000
Gross Profit													662,000		1,769,000		(26,635,000)
Impairment Loss																	25,430,000
Gross Voyage Profit													3,523,000		5,411,000		3,976,000
Interest Expense													768,000		721,000		831,000
Segment Profit (Loss)													(106,000)		1,048,000		(27,466,000)
Segment Assets		35,196,000					38,440,000						35,196,000		38,440,000		40,511,000
Expenditures for Segment Assets													3,766,000		4,483,000		6,695,000
Reconciliation of profit (loss) from segments to consolidated [Abstract]
Total Profit for Reportable Segments													(106,000)		1,048,000		(27,466,000)
Rail-Ferry Service [Member] | Special Purpose vessels [Member]
Segment Reporting Information [Line Items]
Revenue from major customer													33,328,000		36,267,000		26,768,000
Number of vessels owned or operated		2											2
Other [Member]
Segment Profit and Loss [Abstract]
Revenue from External Customers													1,313,000		2,388,000		2,982,000
Intersegment Revenues (Eliminated)													18,638,000		17,419,000		18,642,000
Intersegment Expenses (Eliminated)													(18,638,000)		(17,419,000)		(18,642,000)
Voyage Expenses													62,000		2,070,000		2,590,000
Loss (Income) of Unconsolidated Entities													0		0		0
Gross Voyage Profit Margin Percentage (in hundredths)													95.00%		13.00%		13.00%
Vessel Depreciation and Other													0		9,000		11,000
Gross Profit													1,251,000		309,000		381,000
Impairment Loss																	0
Gross Voyage Profit													1,251,000		318,000		392,000
Interest Expense													543,000		439,000		518,000
Segment Profit (Loss)													708,000		(130,000)		(137,000)
Segment Assets		25,134,000					24,289,000						25,134,000		24,289,000		24,722,000
Expenditures for Segment Assets													540,000		99,000		300,000
Reconciliation of profit (loss) from segments to consolidated [Abstract]
Total Profit for Reportable Segments													708,000		(130,000)		(137,000)
Jones Act [Member]
Segment Profit and Loss [Abstract]
Revenue from External Customers													33,721,000	[1]	29,836,000	[1]	30,109,000	[1]
Intersegment Expenses (Eliminated)													0	[1]	0	[1]	0	[1]
Voyage Expenses													27,230,000	[1]	27,706,000	[1]	26,738,000	[1]
Loss (Income) of Unconsolidated Entities													0	[1]	0	[1]	0	[1]
Gross Voyage Profit Margin Percentage (in hundredths)													19.00%	[1]	7.00%	[1]	11.00%	[1]
Vessel Depreciation and Other													2,120,000	[1]	1,403,000	[1]	1,373,000	[1]
Gross Profit													4,371,000	[1]	727,000	[1]	1,998,000	[1]
Impairment Loss																	0	[1]
Gross Voyage Profit													6,491,000	[1]	2,130,000	[1]	3,371,000	[1]
Interest Expense													1,614,000	[1]	172,000	[1]	222,000	[1]
Segment Profit (Loss)													2,757,000	[1]	555,000	[1]	1,776,000	[1]
Segment Assets		119,377,000	[1]				9,363,000	[1]					119,377,000	[1]	9,363,000	[1]	12,516,000	[1]
Expenditures for Segment Assets													90,319,000	[1]	158,000	[1]	331,000	[1]
Reconciliation of profit (loss) from segments to consolidated [Abstract]
Total Profit for Reportable Segments													2,757,000	[1]	555,000	[1]	1,776,000	[1]
Pure Car/Truck Carriers [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Number of units													7
Segment Profit and Loss [Abstract]
Revenue from External Customers													113,521,000		122,341,000		163,152,000
Intersegment Expenses (Eliminated)													0		0		0
Voyage Expenses													85,688,000		85,940,000		112,500,000
Loss (Income) of Unconsolidated Entities													0		0		0
Gross Voyage Profit Margin Percentage (in hundredths)													25.00%		30.00%		31.00%
Vessel Depreciation and Other													11,059,000		14,167,000		11,364,000
Gross Profit													16,774,000		22,234,000		39,288,000
Impairment Loss																	0
Gross Voyage Profit													27,833,000		36,401,000		50,652,000
Interest Expense													2,933,000		5,828,000		5,402,000
Segment Profit (Loss)													13,841,000		16,406,000		33,886,000
Segment Assets		122,403,000					298,919,000						122,403,000		298,919,000		313,360,000
Expenditures for Segment Assets													5,969,000		86,077,000		1,962,000
Reconciliation of profit (loss) from segments to consolidated [Abstract]
Total Profit for Reportable Segments													13,841,000		16,406,000		33,886,000
Tug and Barge [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Number of units													2
Bulk Carriers [Member]
Segment Reporting Information [Line Items]
Revenue from major customer													26,080,000		19,719,000		0
Number of vessels owned or operated		7											7
Summary of revenues attributable to the major geographic areas [Abstract]
Number of units													2
Segment Profit and Loss [Abstract]
Revenue from External Customers													26,080,000		20,183,000		0
Intersegment Expenses (Eliminated)													0		0		0
Voyage Expenses													19,135,000		9,786,000		0
Loss (Income) of Unconsolidated Entities													(75,000)		63,000		(9,330,000)
Gross Voyage Profit Margin Percentage (in hundredths)													27.00%		51.00%		0.00%
Vessel Depreciation and Other													6,297,000		4,309,000		0
Gross Profit													723,000		6,025,000		9,330,000
Impairment Loss																	0
Gross Voyage Profit													7,020,000		10,334,000		9,330,000
Interest Expense													3,923,000		2,645,000		0
Segment Profit (Loss)													(3,200,000)		3,380,000		9,330,000
Segment Assets		162,921,000					129,692,000						162,921,000		129,692,000		0
Expenditures for Segment Assets													21,899,000		74,603,000		108,338,000
Reconciliation of profit (loss) from segments to consolidated [Abstract]
Total Profit for Reportable Segments													(3,200,000)		3,380,000		9,330,000
Bulk Carriers [Member] | Mini-Bulk Carrier [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Amount of Bulk Carriers Acquired							6,250,000								6,250,000		3,900,000
Vessel [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Number of units													1
Conveyor belt-equipped [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Number of units													1
Specialty Contracts [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Number of units													2
Segment Profit and Loss [Abstract]
Revenue from External Customers													35,526,000		52,026,000		67,133,000
Intersegment Expenses (Eliminated)													0		0		0
Voyage Expenses													26,871,000		35,916,000		44,870,000
Loss (Income) of Unconsolidated Entities													0		0		0
Gross Voyage Profit Margin Percentage (in hundredths)													24.00%		31.00%		33.00%
Vessel Depreciation and Other													2,061,000		1,858,000		0
Gross Profit													6,594,000		14,252,000		22,263,000
Impairment Loss																	0
Gross Voyage Profit													8,655,000		16,110,000		22,263,000
Interest Expense													628,000		556,000		184,000
Segment Profit (Loss)													5,966,000		13,696,000		22,079,000
Segment Assets		27,767,000					28,448,000						27,767,000		28,448,000		7,951,000
Expenditures for Segment Assets													23,695,000		1,120,000		8,036,000
Reconciliation of profit (loss) from segments to consolidated [Abstract]
Total Profit for Reportable Segments													$ 5,966,000		$ 13,696,000		$ 22,079,000
Tug [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Number of units													1
Barge [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Number of units													1

[1] 2012 reflects one month of UOS.