Major Customers And Segment Information (Operating Results, Capital Expenditures And Assets By Reportable Segments) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Operating Revenues	$ 327,861,000	$ 336,784,000	$ 315,563,000	$ 267,064,000	$ 362,368,000	$ 338,855,000	$ 309,225,000	$ 297,849,000	$ 1,247,272,000	$ 1,308,297,000	$ 1,032,497,000
Administrative and general									141,348,000	166,743,000	131,772,000
Depreciation and amortization									134,518,000	131,667,000	106,873,000
Total costs and expenses									1,184,737,000	1,275,879,000	984,198,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges									37,507,000	23,987,000	18,839,000
Operating Income (Loss)	30,307,000	51,508,000	19,254,000	(1,027,000)	9,332,000	20,058,000	(1,499,000)	28,514,000	100,042,000	56,405,000	67,138,000
Derivative gains (losses), net									(8,323,000)	(2,812,000)	(30,055,000)
Foreign currency gains (losses), net									(3,351,000)	1,631,000	540,000
Other, net									586,000	7,148,000	1,018,000
Income (Loss) from Equity Method Investments									7,264,000	(5,764,000)	9,908,000
Income Before Income Tax Expense (Benefit) and Equity in Earnings of 50% or Less Owned Companies									67,632,000	54,572,000	3,769,000
Payments to Acquire Property, Plant, and Equipment									195,901,000	239,350,000	165,264,000
Property, Plant and Equipment, Gross	2,199,183,000				2,238,383,000				2,199,183,000	2,238,383,000
Accumulated depreciation	866,330,000				763,803,000				866,330,000	763,803,000
Property, Plant and Equipment, Net In Service	1,332,853,000				1,474,580,000				1,332,853,000	1,474,580,000
Construction in Progress, Gross	143,482,000				110,296,000				143,482,000	110,296,000
Net property and equipment	1,476,335,000				1,584,876,000				1,476,335,000	1,584,876,000	1,440,657,000
Equity Method Investments	440,853,000				272,535,000				440,853,000	272,535,000
Inventory, Net	27,615,000				25,787,000				27,615,000	25,787,000
Goodwill	17,985,000				17,978,000				17,985,000	17,978,000
Intangible Assets, Net	12,423,000				15,305,000				12,423,000	15,305,000
Total Assets	3,116,233,000				3,700,794,000				3,116,233,000	3,700,794,000	3,928,134,000
Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									567,148,000	519,707,000	376,692,000
Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									212,726,000	224,409,000	187,657,000
Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									194,184,000	179,928,000	161,307,000
Ethanol and Industrial Alcohol [Member]
Segment Reporting Information [Line Items]
Operating Revenues									193,682,000	188,650,000	0
Sales Revenue, Goods, Net									189,500,000	184,900,000
Cost of Goods Sold									180,500,000	185,100,000
Inventory, Raw Materials	1,800,000				2,400,000				1,800,000	2,400,000
Inventory, Work in Process	1,800,000				1,800,000				1,800,000	1,800,000
Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues									79,532,000	195,603,000	306,841,000
Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues									0	0	0
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues									1,247,272,000	1,308,297,000	1,032,497,000
Operating Expenses									908,871,000	977,469,000	745,553,000
Administrative and general									141,348,000	166,743,000	131,772,000
Depreciation and amortization									134,518,000	131,667,000	106,873,000
Total costs and expenses									1,184,737,000	1,275,879,000	984,198,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges									37,507,000	23,987,000	18,839,000
Operating Income (Loss)									100,042,000	56,405,000	67,138,000
Derivative gains (losses), net									(8,323,000)	(2,812,000)	(30,055,000)
Foreign currency gains (losses), net									(3,351,000)	1,631,000	540,000
Other, net									586,000	7,148,000	1,018,000
Income (Loss) from Equity Method Investments									7,264,000	(5,764,000)	9,908,000
Payments to Acquire Property, Plant, and Equipment									195,901,000	239,350,000	165,264,000
Property, Plant and Equipment, Gross	2,199,183,000				2,238,383,000				2,199,183,000	2,238,383,000	1,986,731,000
Accumulated depreciation	866,330,000				763,803,000				866,330,000	763,803,000	665,553,000
Property, Plant and Equipment, Net In Service	1,332,853,000				1,474,580,000				1,332,853,000	1,474,580,000	1,321,178,000
Construction in Progress, Gross	143,482,000				110,296,000				143,482,000	110,296,000	119,479,000
Net property and equipment	1,476,335,000				1,584,876,000				1,476,335,000	1,584,876,000	1,440,657,000
Equity Method Investments	440,853,000				272,535,000				440,853,000	272,535,000	199,490,000
Inventory, Net	27,615,000				25,787,000				27,615,000	25,787,000	12,958,000
Goodwill	17,985,000				17,978,000				17,985,000	17,978,000	56,702,000
Intangible Assets, Net	12,423,000				15,305,000				12,423,000	15,305,000	21,528,000
Other current and long-term assets, excluding cash and near cash assets	315,381,000				341,650,000				315,381,000	341,650,000	378,198,000
Operating Segments [Member] | Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									567,263,000	519,817,000	376,788,000
Operating Expenses									382,045,000	349,680,000	269,203,000
Administrative and general									60,279,000	59,253,000	47,201,000
Depreciation and amortization									65,424,000	61,542,000	48,477,000
Total costs and expenses									507,748,000	470,475,000	364,881,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges									28,664,000	14,876,000	14,661,000
Operating Income (Loss)									88,179,000	64,218,000	26,568,000
Derivative gains (losses), net									83,000	(243,000)	0
Foreign currency gains (losses), net									(2,209,000)	1,077,000	(3,102,000)
Other, net									3,000	2,000	278,000
Income (Loss) from Equity Method Investments									13,522,000	5,214,000	9,189,000
Segment Profit (Loss)									99,578,000	70,268,000	32,933,000
Payments to Acquire Property, Plant, and Equipment									111,517,000	168,778,000	88,248,000
Property, Plant and Equipment, Gross	1,139,639,000				1,158,169,000				1,139,639,000	1,158,169,000	943,108,000
Accumulated depreciation	471,590,000				422,564,000				471,590,000	422,564,000	372,213,000
Property, Plant and Equipment, Net In Service	668,049,000				735,605,000				668,049,000	735,605,000	570,895,000
Construction in Progress, Gross	102,452,000				66,088,000				102,452,000	66,088,000	83,924,000
Net property and equipment	770,501,000				801,693,000				770,501,000	801,693,000	654,819,000
Equity Method Investments	99,160,000				66,805,000				99,160,000	66,805,000	68,330,000
Inventory, Net	6,315,000				6,779,000				6,315,000	6,779,000	6,449,000
Goodwill	13,367,000				13,367,000				13,367,000	13,367,000	13,367,000
Intangible Assets, Net	3,650,000				4,086,000				3,650,000	4,086,000	5,971,000
Other current and long-term assets, excluding cash and near cash assets	149,239,000				139,757,000				149,239,000	139,757,000	125,472,000
Total Assets	1,042,232,000				1,032,487,000				1,042,232,000	1,032,487,000	874,408,000
Operating Segments [Member] | Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									215,613,000	226,561,000	187,657,000
Operating Expenses									152,527,000	158,596,000	119,499,000
Administrative and general									15,410,000	15,924,000	11,339,000
Depreciation and amortization									28,461,000	28,270,000	23,494,000
Total costs and expenses									196,398,000	202,790,000	154,332,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges									6,555,000	7,666,000	2,964,000
Operating Income (Loss)									25,770,000	31,437,000	36,289,000
Derivative gains (losses), net									0	0	0
Foreign currency gains (losses), net									(167,000)	84,000	0
Other, net									0	(1,000)	4,000
Income (Loss) from Equity Method Investments									(7,626,000)	(3,310,000)	4,136,000
Segment Profit (Loss)									17,977,000	28,210,000	40,429,000
Payments to Acquire Property, Plant, and Equipment									37,360,000	28,818,000	44,693,000
Property, Plant and Equipment, Gross	481,421,000				491,653,000				481,421,000	491,653,000	474,618,000
Accumulated depreciation	147,698,000				127,112,000				147,698,000	127,112,000	104,768,000
Property, Plant and Equipment, Net In Service	333,723,000				364,541,000				333,723,000	364,541,000	369,850,000
Construction in Progress, Gross	28,855,000				11,122,000				28,855,000	11,122,000	13,442,000
Net property and equipment	362,578,000				375,663,000				362,578,000	375,663,000	383,292,000
Equity Method Investments	55,411,000				53,844,000				55,411,000	53,844,000	50,183,000
Inventory, Net	2,279,000				2,623,000				2,279,000	2,623,000	2,422,000
Goodwill	2,766,000				2,759,000				2,766,000	2,759,000	4,345,000
Intangible Assets, Net	7,568,000				9,214,000				7,568,000	9,214,000	7,324,000
Other current and long-term assets, excluding cash and near cash assets	69,267,000				75,661,000				69,267,000	75,661,000	72,565,000
Total Assets	499,869,000				519,764,000				499,869,000	519,764,000	520,131,000
Operating Segments [Member] | Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									194,184,000	180,036,000	161,307,000
Operating Expenses									117,283,000	112,125,000	90,708,000
Administrative and general									22,073,000	22,553,000	18,301,000
Depreciation and amortization									31,299,000	30,635,000	30,214,000
Total costs and expenses									170,655,000	165,313,000	139,223,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges									240,000	3,128,000	1,355,000
Operating Income (Loss)									23,769,000	17,851,000	23,439,000
Derivative gains (losses), net									0	0	0
Foreign currency gains (losses), net									(14,000)	6,000	(30,000)
Other, net									760,000	7,452,000	307,000
Income (Loss) from Equity Method Investments									(2,945,000)	(4,148,000)	(74,000)
Segment Profit (Loss)									21,570,000	21,161,000	23,642,000
Payments to Acquire Property, Plant, and Equipment									43,713,000	31,235,000	24,308,000
Property, Plant and Equipment, Gross	498,951,000				506,054,000				498,951,000	506,054,000	524,398,000
Accumulated depreciation	223,667,000				198,943,000				223,667,000	198,943,000	175,978,000
Property, Plant and Equipment, Net In Service	275,284,000				307,111,000				275,284,000	307,111,000	348,420,000
Construction in Progress, Gross	11,324,000				29,972,000				11,324,000	29,972,000	18,055,000
Net property and equipment	286,608,000				337,083,000				286,608,000	337,083,000	366,475,000
Equity Method Investments	197,145,000				67,023,000				197,145,000	67,023,000	12,284,000
Inventory, Net	1,329,000				1,728,000				1,329,000	1,728,000	1,671,000
Goodwill	1,852,000				1,852,000				1,852,000	1,852,000	1,852,000
Intangible Assets, Net	859,000				1,410,000				859,000	1,410,000	1,945,000
Other current and long-term assets, excluding cash and near cash assets	15,097,000				14,183,000				15,097,000	14,183,000	14,131,000
Total Assets	502,890,000				423,279,000				502,890,000	423,279,000	398,358,000
Operating Segments [Member] | Ethanol and Industrial Alcohol [Member]
Segment Reporting Information [Line Items]
Operating Revenues									193,682,000	188,650,000	0
Operating Expenses									184,649,000	183,442,000	0
Administrative and general									2,031,000	1,920,000	256,000
Depreciation and amortization									5,797,000	5,757,000	0
Total costs and expenses									192,477,000	191,119,000	256,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges									0	0	0
Operating Income (Loss)									1,205,000	(2,469,000)	(256,000)
Derivative gains (losses), net									(2,078,000)	(856,000)	0
Foreign currency gains (losses), net									0	0	0
Other, net									0	0	0
Income (Loss) from Equity Method Investments									0	6,154,000	(1,815,000)
Segment Profit (Loss)									(873,000)	2,829,000	(2,071,000)
Payments to Acquire Property, Plant, and Equipment									1,115,000	96,000	0
Property, Plant and Equipment, Gross	44,166,000				43,789,000				44,166,000	43,789,000	0
Accumulated depreciation	11,390,000				5,679,000				11,390,000	5,679,000	0
Property, Plant and Equipment, Net In Service	32,776,000				38,110,000				32,776,000	38,110,000	0
Construction in Progress, Gross	738,000				0				738,000	0	0
Net property and equipment	33,514,000				38,110,000				33,514,000	38,110,000	0
Equity Method Investments	0				0				0	0	11,790,000
Inventory, Net	16,172,000				11,770,000				16,172,000	11,770,000	0
Goodwill	0				0				0	0	0
Intangible Assets, Net	7,000				93,000				7,000	93,000	0
Other current and long-term assets, excluding cash and near cash assets	5,409,000				6,533,000				5,409,000	6,533,000	8,000
Total Assets	55,102,000				56,506,000				55,102,000	56,506,000	11,798,000
Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues									79,532,000	195,731,000	306,867,000
Operating Expenses									75,254,000	175,957,000	266,168,000
Administrative and general									6,296,000	23,824,000	19,370,000
Depreciation and amortization									378,000	2,874,000	2,830,000
Total costs and expenses									81,928,000	202,655,000	288,368,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges									1,907,000	(1,527,000)	3,000
Operating Income (Loss)									(489,000)	(8,451,000)	18,502,000
Derivative gains (losses), net									210,000	910,000	(980,000)
Foreign currency gains (losses), net									(342,000)	2,000	277,000
Other, net									12,000	0	950,000
Income (Loss) from Equity Method Investments									4,313,000	(9,674,000)	(1,528,000)
Segment Profit (Loss)									3,704,000	(17,213,000)	17,221,000
Payments to Acquire Property, Plant, and Equipment									385,000	6,576,000	4,972,000
Property, Plant and Equipment, Gross	3,967,000				8,276,000				3,967,000	8,276,000	18,610,000
Accumulated depreciation	662,000				398,000				662,000	398,000	3,002,000
Property, Plant and Equipment, Net In Service	3,305,000				7,878,000				3,305,000	7,878,000	15,608,000
Construction in Progress, Gross	113,000				3,040,000				113,000	3,040,000	314,000
Net property and equipment	3,418,000				10,918,000				3,418,000	10,918,000	15,922,000
Equity Method Investments	89,137,000				84,863,000				89,137,000	84,863,000	56,903,000
Inventory, Net	1,520,000				2,887,000				1,520,000	2,887,000	2,416,000
Goodwill	0				0				0	0	37,138,000
Intangible Assets, Net	339,000				502,000				339,000	502,000	6,288,000
Other current and long-term assets, excluding cash and near cash assets	47,584,000				72,123,000				47,584,000	72,123,000	137,008,000
Total Assets	141,998,000				171,293,000				141,998,000	171,293,000	255,675,000
Operating Segments [Member] | Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(3,002,000)	(2,498,000)	(122,000)
Operating Expenses									(2,887,000)	(2,331,000)	(25,000)
Administrative and general									35,259,000	43,269,000	35,305,000
Depreciation and amortization									3,159,000	2,589,000	1,858,000
Total costs and expenses									35,531,000	43,527,000	37,138,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges									141,000	(156,000)	(144,000)
Operating Income (Loss)									(38,392,000)	(46,181,000)	(37,404,000)
Derivative gains (losses), net									(6,538,000)	(2,623,000)	(29,075,000)
Foreign currency gains (losses), net									(619,000)	462,000	3,395,000
Other, net									(189,000)	(305,000)	(521,000)
Income (Loss) from Equity Method Investments									0	0	0
Payments to Acquire Property, Plant, and Equipment									1,811,000	3,847,000	3,043,000
Property, Plant and Equipment, Gross	31,039,000				30,442,000				31,039,000	30,442,000	25,997,000
Accumulated depreciation	11,323,000				9,107,000				11,323,000	9,107,000	9,592,000
Property, Plant and Equipment, Net In Service	19,716,000				21,335,000				19,716,000	21,335,000	16,405,000
Construction in Progress, Gross	0				74,000				0	74,000	3,744,000
Net property and equipment	19,716,000				21,409,000				19,716,000	21,409,000	20,149,000
Equity Method Investments	0				0				0	0	0
Inventory, Net	0				0				0	0	0
Goodwill	0				0				0	0	0
Intangible Assets, Net	0				0				0	0	0
Other current and long-term assets, excluding cash and near cash assets	28,785,000				33,393,000				28,785,000	33,393,000	29,014,000
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues									0	0	0
Intersegment Eliminations [Member] | Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(115,000)	110,000	96,000
Intersegment Eliminations [Member] | Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(2,887,000)	2,152,000	0
Intersegment Eliminations [Member] | Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									0	108,000	0
Intersegment Eliminations [Member] | Ethanol and Industrial Alcohol [Member]
Segment Reporting Information [Line Items]
Operating Revenues									0	0	0
Intersegment Eliminations [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues									0	128,000	26,000
Intersegment Eliminations [Member] | Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues									3,002,000	(2,498,000)	(122,000)
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Other Income (Expense) not included in Segment Profit									21,322,000	7,800,000	34,872,000
Less Equity Earnings included in Segment Profit									(7,264,000)	5,764,000	(9,908,000)
Cash and near cash assets	825,641,000				493,786,000				825,641,000	493,786,000	729,635,000
Assets of Disposal Group, Including Discontinued Operation					$ 948,877,000					$ 948,877,000	$ 1,088,966,000