Segment Information (Operating Results, Capital Expenditures And Assets By Reportable Segments) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Derivative gains (losses) on cash flow hedges	$ 50,000	$ 331,000
Operating Revenues	328,224,000	315,563,000	638,241,000	582,627,000
Costs and Expenses [Abstract]
Administrative and general	34,686,000	34,718,000	72,763,000	70,363,000
Depreciation and amortization	33,220,000	33,783,000	66,612,000	67,331,000
Total costs and expenses	299,812,000	308,614,000	590,257,000	578,720,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	4,295,000	12,305,000	8,973,000	14,320,000
Operating Income (Loss)	32,707,000	19,254,000	56,957,000	18,227,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	94,000	(825,000)	(143,000)	(2,932,000)
Foreign currency gains (losses), net	1,720,000	(916,000)	1,521,000	(4,927,000)
Other Nonoperating Income (Expense)	10,213,000	195,000	6,558,000	198,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	(512,000)	7,710,000	1,709,000	6,841,000
Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	41,037,000	19,561,000	58,906,000	6,741,000
Capital Expenditures			273,669,000	87,931,000
Property, Plant and Equipment, Gross	2,216,627,000		2,216,627,000		2,199,183,000
Accumulated depreciation	888,442,000		888,442,000		866,330,000
Property, Plant and Equipment, Net In Service	1,328,185,000		1,328,185,000		1,332,853,000
Construction in Progress, Gross	297,523,000		297,523,000		143,482,000
Net property and equipment	1,625,708,000		1,625,708,000		1,476,335,000
Inventories	20,207,000		20,207,000		27,615,000
Goodwill	18,012,000		18,012,000		17,985,000
Intangible Assets, Net	10,754,000		10,754,000		12,423,000
Total assets	3,295,993,000	2,768,333,000	3,295,993,000	2,768,333,000	3,116,233,000
Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	138,214,000	138,650,000	267,171,000	262,642,000
Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	55,200,000	46,780,000	112,211,000	96,203,000
Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	53,575,000	48,103,000	105,976,000	94,579,000
Ethanol and Industrial Alcohol [Member]
Segment Reporting Information [Line Items]
Operating Revenues	72,798,000	61,378,000
Illinois Corn Processing LLC [Member]
Segment Reporting Information [Line Items]
Operating Revenues			131,454,000	94,227,000
Other Income and Expenses [Abstract]
Sales Revenue, Goods, Net			126,100,000	90,200,000
Cost of Goods Sold			98,200,000	89,400,000
Inventory, Raw Materials	2,200,000	2,800,000	2,200,000	2,800,000
Inventory, Work in Process	1,300,000	2,200,000	1,300,000	2,200,000
Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues	8,437,000	20,652,000	21,429,000	34,976,000
Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0	0
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues	328,224,000	315,563,000	638,241,000	582,627,000
Costs and Expenses [Abstract]
Operating Expenses	231,906,000	240,113,000	450,882,000	441,026,000
Administrative and general	34,686,000	34,718,000	72,763,000	70,363,000
Depreciation and amortization	33,220,000	33,783,000	66,612,000	67,331,000
Total costs and expenses	299,812,000	308,614,000	590,257,000	578,720,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	4,295,000	12,305,000	8,973,000	14,320,000
Operating Income (Loss)	32,707,000	19,254,000	56,957,000	18,227,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	94,000	(825,000)	(143,000)	(2,932,000)
Foreign currency gains (losses), net	1,720,000	(916,000)	1,521,000	(4,927,000)
Other Nonoperating Income (Expense)	10,213,000	195,000	6,558,000	198,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	(512,000)	7,710,000	1,709,000	6,841,000
Capital Expenditures			273,669,000	87,931,000
Property, Plant and Equipment, Gross	2,216,627,000	2,212,929,000	2,216,627,000	2,212,929,000
Accumulated depreciation	888,442,000	806,672,000	888,442,000	806,672,000
Property, Plant and Equipment, Net In Service	1,328,185,000	1,406,257,000	1,328,185,000	1,406,257,000
Construction in Progress, Gross	297,523,000	133,985,000	297,523,000	133,985,000
Net property and equipment	1,625,708,000	1,540,242,000	1,625,708,000	1,540,242,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	484,164,000	293,793,000	484,164,000	293,793,000
Inventories	20,207,000	22,955,000	20,207,000	22,955,000
Goodwill	18,012,000	17,978,000	18,012,000	17,978,000
Intangible Assets, Net	10,754,000	14,594,000	10,754,000	14,594,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	311,256,000	289,573,000	311,256,000	289,573,000
Operating Segments [Member] | Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	138,247,000	138,678,000	267,248,000	262,694,000
Costs and Expenses [Abstract]
Operating Expenses	93,755,000	97,581,000	187,798,000	187,612,000
Administrative and general	13,426,000	14,235,000	28,586,000	29,062,000
Depreciation and amortization	16,448,000	16,460,000	32,752,000	32,747,000
Total costs and expenses	123,629,000	128,276,000	249,136,000	249,421,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	3,526,000	7,895,000	11,264,000	10,234,000
Operating Income (Loss)	18,144,000	18,297,000	29,376,000	23,507,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	(70,000)	175,000	(131,000)	325,000
Foreign currency gains (losses), net	1,322,000	(833,000)	1,429,000	(4,097,000)
Other Nonoperating Income (Expense)	14,739,000	11,000	14,739,000	11,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	2,244,000	7,694,000	4,885,000	9,007,000
Segment Profit (Loss)	36,379,000	25,344,000	50,298,000	28,753,000
Capital Expenditures			46,621,000	49,764,000
Property, Plant and Equipment, Gross	1,154,174,000	1,151,751,000	1,154,174,000	1,151,751,000
Accumulated depreciation	499,092,000	439,211,000	499,092,000	439,211,000
Property, Plant and Equipment, Net In Service	655,082,000	712,540,000	655,082,000	712,540,000
Construction in Progress, Gross	91,824,000	90,847,000	91,824,000	90,847,000
Net property and equipment	746,906,000	803,387,000	746,906,000	803,387,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	129,775,000	84,418,000	129,775,000	84,418,000
Inventories	5,571,000	5,885,000	5,571,000	5,885,000
Goodwill	13,367,000	13,367,000	13,367,000	13,367,000
Intangible Assets, Net	2,784,000	4,584,000	2,784,000	4,584,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	154,188,000	146,551,000	154,188,000	146,551,000
Total assets	1,052,591,000	1,058,192,000	1,052,591,000	1,058,192,000
Operating Segments [Member] | Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	56,007,000	47,357,000	113,966,000	97,434,000
Costs and Expenses [Abstract]
Operating Expenses	45,047,000	35,193,000	84,721,000	71,582,000
Administrative and general	3,835,000	3,921,000	8,172,000	7,945,000
Depreciation and amortization	7,564,000	7,078,000	14,934,000	14,162,000
Total costs and expenses	56,446,000	46,192,000	107,827,000	93,689,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	810,000	4,296,000	1,663,000	4,993,000
Operating Income (Loss)	371,000	5,461,000	7,802,000	8,738,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	0	0	0	0
Foreign currency gains (losses), net	474,000	219,000	147,000	82,000
Other Nonoperating Income (Expense)	0	0	(38,000)	0
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	(3,335,000)	1,000	(3,747,000)	(2,386,000)
Segment Profit (Loss)	(2,490,000)	5,681,000	4,164,000	6,434,000
Capital Expenditures			44,086,000	9,238,000
Property, Plant and Equipment, Gross	519,586,000	466,553,000	519,586,000	466,553,000
Accumulated depreciation	161,091,000	134,235,000	161,091,000	134,235,000
Property, Plant and Equipment, Net In Service	358,495,000	332,318,000	358,495,000	332,318,000
Construction in Progress, Gross	32,175,000	17,700,000	32,175,000	17,700,000
Net property and equipment	390,670,000	350,018,000	390,670,000	350,018,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	61,653,000	55,875,000	61,653,000	55,875,000
Inventories	2,309,000	2,260,000	2,309,000	2,260,000
Goodwill	2,793,000	2,759,000	2,793,000	2,759,000
Intangible Assets, Net	7,085,000	8,416,000	7,085,000	8,416,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	55,819,000	37,260,000	55,819,000	37,260,000
Total assets	520,329,000	456,588,000	520,329,000	456,588,000
Operating Segments [Member] | Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	53,575,000	48,103,000	105,976,000	94,579,000
Costs and Expenses [Abstract]
Operating Expenses	28,018,000	29,554,000	55,015,000	56,168,000
Administrative and general	5,421,000	6,124,000	11,317,000	11,301,000
Depreciation and amortization	7,115,000	7,907,000	14,869,000	15,704,000
Total costs and expenses	40,554,000	43,585,000	81,201,000	83,173,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	(41,000)	114,000	(41,000)	(2,955,000)
Operating Income (Loss)	12,980,000	4,632,000	24,734,000	8,451,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	0	0	0	0
Foreign currency gains (losses), net	1,000	(8,000)	(9,000)	(15,000)
Other Nonoperating Income (Expense)	158,000	188,000	(3,775,000)	202,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,564,000	(403,000)	2,317,000	(1,908,000)
Segment Profit (Loss)	14,703,000	4,409,000	23,267,000	6,730,000
Capital Expenditures			165,160,000	27,048,000
Property, Plant and Equipment, Gross	451,123,000	517,409,000	451,123,000	517,409,000
Accumulated depreciation	200,908,000	214,372,000	200,908,000	214,372,000
Property, Plant and Equipment, Net In Service	250,215,000	303,037,000	250,215,000	303,037,000
Construction in Progress, Gross	171,204,000	22,037,000	171,204,000	22,037,000
Net property and equipment	421,419,000	325,074,000	421,419,000	325,074,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	205,110,000	66,786,000	205,110,000	66,786,000
Inventories	1,438,000	1,427,000	1,438,000	1,427,000
Goodwill	1,852,000	1,852,000	1,852,000	1,852,000
Intangible Assets, Net	575,000	1,134,000	575,000	1,134,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	19,816,000	16,021,000	19,816,000	16,021,000
Total assets	650,210,000	412,294,000	650,210,000	412,294,000
Operating Segments [Member] | Ethanol and Industrial Alcohol [Member]
Segment Reporting Information [Line Items]
Operating Revenues	72,798,000	61,378,000
Costs and Expenses [Abstract]
Operating Expenses	56,429,000	59,402,000
Administrative and general	594,000	477,000
Depreciation and amortization	1,010,000	1,489,000
Total costs and expenses	58,033,000	61,368,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	0
Operating Income (Loss)	14,765,000	10,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	(1,519,000)	473,000
Foreign currency gains (losses), net	0	0
Other Nonoperating Income (Expense)	300,000	0
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	0
Segment Profit (Loss)	13,546,000	483,000
Operating Segments [Member] | Illinois Corn Processing LLC [Member]
Segment Reporting Information [Line Items]
Operating Revenues			131,454,000	94,227,000
Costs and Expenses [Abstract]
Operating Expenses			103,703,000	93,447,000
Administrative and general			1,105,000	1,138,000
Depreciation and amortization			2,000,000	2,978,000
Total costs and expenses			106,808,000	97,563,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges			0	0
Operating Income (Loss)			24,646,000	(3,336,000)
Other Income and Expenses [Abstract]
Derivative gains (losses), net			(801,000)	512,000
Foreign currency gains (losses), net			0	0
Other Nonoperating Income (Expense)			493,000	0
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax			0	0
Segment Profit (Loss)			24,338,000	(2,824,000)
Capital Expenditures			2,098,000	217,000
Property, Plant and Equipment, Gross	44,808,000	44,006,000	44,808,000	44,006,000
Accumulated depreciation	13,369,000	8,614,000	13,369,000	8,614,000
Property, Plant and Equipment, Net In Service	31,439,000	35,392,000	31,439,000	35,392,000
Construction in Progress, Gross	2,156,000	0	2,156,000	0
Net property and equipment	33,595,000	35,392,000	33,595,000	35,392,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	0	0	0	0
Inventories	9,926,000	12,164,000	9,926,000	12,164,000
Goodwill	0	0	0	0
Intangible Assets, Net	0	50,000	0	50,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	13,559,000	10,925,000	13,559,000	10,925,000
Total assets	57,080,000	58,531,000	57,080,000	58,531,000
Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues	8,437,000	20,652,000	21,429,000	34,976,000
Costs and Expenses [Abstract]
Operating Expenses	9,464,000	18,960,000	21,400,000	33,448,000
Administrative and general	3,449,000	1,323,000	6,560,000	2,979,000
Depreciation and amortization	82,000	96,000	167,000	195,000
Total costs and expenses	12,995,000	20,379,000	28,127,000	36,622,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	0	(409,000)	1,907,000
Operating Income (Loss)	(4,558,000)	273,000	(7,107,000)	261,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	1,500,000	(450,000)	767,000	392,000
Foreign currency gains (losses), net	53,000	(169,000)	62,000	(336,000)
Other Nonoperating Income (Expense)	(5,013,000)	0	(4,838,000)	54,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	(985,000)	418,000	(1,746,000)	2,128,000
Segment Profit (Loss)	(9,003,000)	72,000	(12,862,000)	2,499,000
Capital Expenditures			123,000	357,000
Property, Plant and Equipment, Gross	3,760,000	3,989,000	3,760,000	3,989,000
Accumulated depreciation	769,000	531,000	769,000	531,000
Property, Plant and Equipment, Net In Service	2,991,000	3,458,000	2,991,000	3,458,000
Construction in Progress, Gross	224,000	2,087,000	224,000	2,087,000
Net property and equipment	3,215,000	5,545,000	3,215,000	5,545,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	87,626,000	86,714,000	87,626,000	86,714,000
Inventories	963,000	1,219,000	963,000	1,219,000
Goodwill	0	0	0	0
Intangible Assets, Net	310,000	410,000	310,000	410,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	49,232,000	56,591,000	49,232,000	56,591,000
Total assets	141,346,000	150,479,000	141,346,000	150,479,000
Operating Segments [Member] | Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	(840,000)	(605,000)	(1,832,000)	(1,283,000)
Costs and Expenses [Abstract]
Operating Expenses	(807,000)	(577,000)	(1,755,000)	(1,231,000)
Administrative and general	7,961,000	8,638,000	17,023,000	17,938,000
Depreciation and amortization	1,001,000	753,000	1,890,000	1,545,000
Total costs and expenses	8,155,000	8,814,000	17,158,000	18,252,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	0	(3,504,000)	141,000
Operating Income (Loss)	(8,995,000)	(9,419,000)	(22,494,000)	(19,394,000)
Other Income and Expenses [Abstract]
Derivative gains (losses), net	183,000	(1,023,000)	22,000	(4,161,000)
Foreign currency gains (losses), net	(130,000)	(125,000)	(108,000)	(561,000)
Other Nonoperating Income (Expense)	29,000	(4,000)	(23,000)	(69,000)
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	0	0	0
Capital Expenditures				1,307,000
Property, Plant and Equipment, Gross	43,176,000	29,221,000	43,176,000	29,221,000
Accumulated depreciation	13,213,000	9,709,000	13,213,000	9,709,000
Property, Plant and Equipment, Net In Service	29,963,000	19,512,000	29,963,000	19,512,000
Construction in Progress, Gross		1,314,000		1,314,000
Net property and equipment	29,903,000	20,826,000	29,903,000	20,826,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	0	0	0	0
Inventories	0	0	0	0
Goodwill	0	0	0	0
Intangible Assets, Net	0	0	0	0
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	18,642,000	22,225,000	18,642,000	22,225,000
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0	0
Intersegment Eliminations [Member] | Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	(33,000)	28,000	(77,000)	52,000
Intersegment Eliminations [Member] | Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	(807,000)	577,000	(1,755,000)	1,231,000
Intersegment Eliminations [Member] | Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0	0
Intersegment Eliminations [Member] | Ethanol and Industrial Alcohol [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0
Intersegment Eliminations [Member] | Illinois Corn Processing LLC [Member]
Segment Reporting Information [Line Items]
Operating Revenues			0	0
Intersegment Eliminations [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0	0
Intersegment Eliminations [Member] | Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	840,000	(605,000)	1,832,000	(1,283,000)
Segment Reconciling Items [Member]
Other Income and Expenses [Abstract]
Other Income (Expense) not included in Segment Profit	3,697,000	(1,853,000)	5,987,000	3,825,000
Less Equity Earnings (Loss) included in Segment Profit	512,000	(7,710,000)	(1,709,000)	(6,841,000)
Cash And Near Cash Assets	825,892,000	589,198,000	825,892,000	589,198,000
Assets of Disposal Group, Including Discontinued Operation		0		0
Interest Rate Swap Agreements [Member]
Segment Reporting Information [Line Items]
Derivative gains (losses) on cash flow hedges			$ (23,000)	$ 380,000