Segment Information (Operating Results, Capital Expenditures And Assets By Reportable Segments) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Operating Revenues	$ 310,017,000	$ 267,064,000
Costs and Expenses [Abstract]
Administrative and general	38,077,000	35,645,000
Depreciation and amortization	33,392,000	33,548,000
Total costs and expenses	290,445,000	270,106,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	4,678,000	2,015,000
Operating Income (Loss)	24,250,000	(1,027,000)
Other Income and Expenses [Abstract]
Derivative gains (losses), net	(237,000)	(2,107,000)
Foreign currency gains (losses), net	(199,000)	(4,011,000)
Other Nonoperating Income (Expense)	(3,655,000)	3,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	2,221,000	(869,000)
Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	17,869,000	(12,820,000)
Capital Expenditures	219,129,000	33,855,000
Property, Plant and Equipment, Gross	2,224,212,000		2,199,183,000
Accumulated depreciation	894,511,000		866,330,000
Property, Plant and Equipment, Net In Service	1,329,701,000		1,332,853,000
Construction in Progress, Gross	325,529,000		143,482,000
Net property and equipment	1,655,230,000		1,476,335,000
Inventories	24,962,000		27,615,000
Goodwill	17,963,000		17,985,000
Intangible Assets, Net	11,567,000		12,423,000
Total assets	3,145,035,000	2,715,487,000	3,116,233,000
Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	128,957,000	123,992,000
Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	57,011,000	49,423,000
Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	52,401,000	46,476,000
Illinois Corn Processing LLC [Member]
Segment Reporting Information [Line Items]
Operating Revenues	58,656,000	32,849,000
Other Income and Expenses [Abstract]
Sales Revenue, Goods, Net	57,400,000	32,100,000
Cost of Goods Sold	45,800,000	34,400,000
Inventory, Raw Materials	2,200,000	3,000,000
Inventory, Work in Process	1,800,000	2,400,000
Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues	12,992,000	14,324,000
Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues	310,017,000	267,064,000
Costs and Expenses [Abstract]
Operating Expenses	218,976,000	200,913,000
Administrative and general	38,077,000	35,645,000
Depreciation and amortization	33,392,000	33,548,000
Total costs and expenses	290,445,000	270,106,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	4,678,000	2,015,000
Operating Income (Loss)	24,250,000	(1,027,000)
Other Income and Expenses [Abstract]
Derivative gains (losses), net	(237,000)	(2,107,000)
Foreign currency gains (losses), net	(199,000)	(4,011,000)
Other Nonoperating Income (Expense)	(3,655,000)	3,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	2,221,000	(869,000)
Capital Expenditures	219,129,000	33,855,000
Property, Plant and Equipment, Gross	2,224,212,000	2,186,892,000
Accumulated depreciation	894,511,000	785,765,000
Property, Plant and Equipment, Net In Service	1,329,701,000	1,401,127,000
Construction in Progress, Gross	325,529,000	113,381,000
Net property and equipment	1,655,230,000	1,514,508,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	456,446,000	299,778,000
Inventories	24,962,000	31,966,000
Goodwill	17,963,000	17,978,000
Intangible Assets, Net	11,567,000	15,754,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	295,726,000	277,968,000
Operating Segments [Member] | Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	129,001,000	124,016,000
Costs and Expenses [Abstract]
Operating Expenses	94,043,000	90,031,000
Administrative and general	15,160,000	14,827,000
Depreciation and amortization	16,304,000	16,287,000
Total costs and expenses	125,507,000	121,145,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	7,738,000	2,339,000
Operating Income (Loss)	11,232,000	5,210,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	(61,000)	150,000
Foreign currency gains (losses), net	107,000	(3,264,000)
Other Nonoperating Income (Expense)	0	0
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	2,641,000	1,313,000
Segment Profit (Loss)	13,919,000	3,409,000
Capital Expenditures	22,019,000	19,920,000
Property, Plant and Equipment, Gross	1,154,201,000	1,110,480,000
Accumulated depreciation	483,230,000	428,766,000
Property, Plant and Equipment, Net In Service	670,971,000	681,714,000
Construction in Progress, Gross	106,872,000	61,447,000
Net property and equipment	777,843,000	743,161,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	102,543,000	85,311,000
Inventories	6,110,000	6,497,000
Goodwill	13,367,000	13,367,000
Intangible Assets, Net	3,217,000	5,105,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	146,796,000	136,661,000
Total assets	1,049,876,000	990,102,000
Operating Segments [Member] | Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	57,959,000	50,077,000
Costs and Expenses [Abstract]
Operating Expenses	39,674,000	36,389,000
Administrative and general	4,337,000	4,024,000
Depreciation and amortization	7,370,000	7,084,000
Total costs and expenses	51,381,000	47,497,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	853,000	697,000
Operating Income (Loss)	7,431,000	3,277,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	0	0
Foreign currency gains (losses), net	(327,000)	(137,000)
Other Nonoperating Income (Expense)	(38,000)	0
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	(412,000)	(2,387,000)
Segment Profit (Loss)	6,654,000	753,000
Capital Expenditures	22,162,000	5,727,000
Property, Plant and Equipment, Gross	495,360,000	493,140,000
Accumulated depreciation	154,706,000	133,827,000
Property, Plant and Equipment, Net In Service	340,654,000	359,313,000
Construction in Progress, Gross	36,346,000	15,335,000
Net property and equipment	377,000,000	374,648,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	64,778,000	55,105,000
Inventories	2,705,000	2,297,000
Goodwill	2,744,000	2,759,000
Intangible Assets, Net	7,306,000	8,824,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	50,583,000	37,787,000
Total assets	505,116,000	481,420,000
Operating Segments [Member] | Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	52,401,000	46,476,000
Costs and Expenses [Abstract]
Operating Expenses	26,997,000	26,614,000
Administrative and general	5,896,000	5,177,000
Depreciation and amortization	7,754,000	7,797,000
Total costs and expenses	40,647,000	39,588,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	(3,069,000)
Operating Income (Loss)	11,754,000	3,819,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	0	0
Foreign currency gains (losses), net	(10,000)	(7,000)
Other Nonoperating Income (Expense)	(3,933,000)	14,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	753,000	(1,505,000)
Segment Profit (Loss)	8,564,000	2,321,000
Capital Expenditures	157,712,000	6,814,000
Property, Plant and Equipment, Gross	499,084,000	506,279,000
Accumulated depreciation	231,279,000	206,603,000
Property, Plant and Equipment, Net In Service	267,805,000	299,676,000
Construction in Progress, Gross	164,351,000	33,444,000
Net property and equipment	432,156,000	333,120,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	199,997,000	65,941,000
Inventories	1,298,000	1,284,000
Goodwill	1,852,000	1,852,000
Intangible Assets, Net	717,000	1,272,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	19,032,000	18,316,000
Total assets	655,052,000	421,785,000
Operating Segments [Member] | Illinois Corn Processing LLC [Member]
Segment Reporting Information [Line Items]
Operating Revenues	58,656,000	32,849,000
Costs and Expenses [Abstract]
Operating Expenses	47,274,000	34,045,000
Administrative and general	511,000	661,000
Depreciation and amortization	990,000	1,489,000
Total costs and expenses	48,775,000	36,195,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	0
Operating Income (Loss)	9,881,000	(3,346,000)
Other Income and Expenses [Abstract]
Derivative gains (losses), net	718,000	39,000
Foreign currency gains (losses), net	0	0
Other Nonoperating Income (Expense)	193,000	0
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	0
Segment Profit (Loss)	10,792,000	(3,307,000)
Capital Expenditures	1,379,000	0
Property, Plant and Equipment, Gross	44,166,000	43,788,000
Accumulated depreciation	12,374,000	7,146,000
Property, Plant and Equipment, Net In Service	31,792,000	36,642,000
Construction in Progress, Gross	2,118,000	0
Net property and equipment	33,910,000	36,642,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	0	0
Inventories	13,600,000	19,868,000
Goodwill	0	0
Intangible Assets, Net	0	72,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	15,049,000	5,947,000
Total assets	62,559,000	62,529,000
Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues	12,992,000	14,324,000
Costs and Expenses [Abstract]
Operating Expenses	11,936,000	14,488,000
Administrative and general	3,111,000	1,656,000
Depreciation and amortization	85,000	99,000
Total costs and expenses	15,132,000	16,243,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	(409,000)	1,907,000
Operating Income (Loss)	(2,549,000)	(12,000)
Other Income and Expenses [Abstract]
Derivative gains (losses), net	(733,000)	842,000
Foreign currency gains (losses), net	9,000	(167,000)
Other Nonoperating Income (Expense)	175,000	54,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	(761,000)	1,710,000
Segment Profit (Loss)	(3,859,000)	2,427,000
Capital Expenditures	100,000	357,000
Property, Plant and Equipment, Gross	3,750,000	4,032,000
Accumulated depreciation	710,000	467,000
Property, Plant and Equipment, Net In Service	3,040,000	3,565,000
Construction in Progress, Gross	201,000	2,063,000
Net property and equipment	3,241,000	5,628,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	89,128,000	93,421,000
Inventories	1,249,000	2,020,000
Goodwill	0	0
Intangible Assets, Net	327,000	481,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	42,552,000	47,877,000
Total assets	136,497,000	149,427,000
Operating Segments [Member] | Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	(992,000)	(678,000)
Costs and Expenses [Abstract]
Operating Expenses	(948,000)	(654,000)
Administrative and general	9,062,000	9,300,000
Depreciation and amortization	889,000	792,000
Total costs and expenses	9,003,000	9,438,000
Gain (Loss) on Sale of Assets and Asset Impairment Charges	(3,504,000)	141,000
Operating Income (Loss)	(13,499,000)	(9,975,000)
Other Income and Expenses [Abstract]
Derivative gains (losses), net	(161,000)	(3,138,000)
Foreign currency gains (losses), net	22,000	(436,000)
Other Nonoperating Income (Expense)	(52,000)	(65,000)
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	0
Capital Expenditures	15,757,000	1,037,000
Property, Plant and Equipment, Gross	27,651,000	29,173,000
Accumulated depreciation	12,212,000	8,956,000
Property, Plant and Equipment, Net In Service	15,439,000	20,217,000
Construction in Progress, Gross	15,641,000	1,092,000
Net property and equipment	31,080,000	21,309,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	0	0
Inventories	0	0
Goodwill	0	0
Intangible Assets, Net	0	0
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	21,714,000	31,380,000
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0
Intersegment Eliminations [Member] | Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	(44,000)	24,000
Intersegment Eliminations [Member] | Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	(948,000)	654,000
Intersegment Eliminations [Member] | Shipping Services [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
Intersegment Eliminations [Member] | Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	992,000	(678,000)
Segment Reconciling Items [Member]
Other Income and Expenses [Abstract]
Other Income (Expense) not included in Segment Profit	2,290,000	5,678,000
Less Equity Earnings (Loss) included in Segment Profit	(2,221,000)	869,000
Cash And Near Cash Assets	683,141,000	557,151,000
Assets of Disposal Group, Including Discontinued Operation		$ 384,000