Segment Information (Operating Results, Capital Expenditures And Assets By Reportable Segments) (Details) (USD $)	3 Months Ended				9 Months Ended					3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended				6 Months Ended	9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011		Dec. 31, 2011	Sep. 30, 2012 Offshore Marine Services [Member]		Sep. 30, 2011 Offshore Marine Services [Member]		Sep. 30, 2012 Offshore Marine Services [Member]		Sep. 30, 2011 Offshore Marine Services [Member]		Sep. 30, 2012 Aviation Services [Member]		Sep. 30, 2011 Aviation Services [Member]		Sep. 30, 2012 Aviation Services [Member]		Sep. 30, 2011 Aviation Services [Member]		Sep. 30, 2012 Inland River Services [Member]		Sep. 30, 2011 Inland River Services [Member]		Sep. 30, 2012 Inland River Services [Member]		Sep. 30, 2011 Inland River Services [Member]		Sep. 30, 2012 Marine Transportation Services [Member]		Sep. 30, 2011 Marine Transportation Services [Member]		Sep. 30, 2012 Marine Transportation Services [Member]		Sep. 30, 2011 Marine Transportation Services [Member]		Sep. 30, 2012 Emergency and Crisis Services [Member]		Sep. 30, 2011 Emergency and Crisis Services [Member]		Sep. 30, 2012 Emergency and Crisis Services [Member]		Sep. 30, 2011 Emergency and Crisis Services [Member]		Sep. 30, 2012 Commodity Trading And Logistics [Member]		Sep. 30, 2011 Commodity Trading And Logistics [Member]		Jun. 30, 2011 Commodity Trading And Logistics [Member]	Sep. 30, 2012 Commodity Trading And Logistics [Member]		Sep. 30, 2011 Commodity Trading And Logistics [Member]		Sep. 30, 2012 Other [Member]		Sep. 30, 2011 Other [Member]		Sep. 30, 2012 Other [Member]		Sep. 30, 2011 Other [Member]		Sep. 30, 2012 Corporate And Eliminations [Member]		Sep. 30, 2011 Corporate And Eliminations [Member]		Sep. 30, 2012 Corporate And Eliminations [Member]		Sep. 30, 2011 Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Total assets	$ 3,917,236,000		$ 3,662,318,000		$ 3,917,236,000		$ 3,662,318,000		$ 3,928,134,000
Operating Revenue:
External customers	462,058,000		545,089,000		1,454,365,000		1,492,383,000			134,294,000		93,256,000		378,591,000		266,939,000		77,989,000		71,804,000		202,024,000		196,434,000		49,592,000		45,349,000		149,238,000		127,959,000		27,266,000		24,696,000		79,166,000		66,169,000		9,227,000		14,080,000		27,846,000		64,188,000		145,725,000		279,178,000			562,166,000		718,511,000		17,965,000		16,726,000		55,334,000		52,183,000		0		0		0		0
Intersegment	0		0		0		0			28,000		21,000		93,000		68,000		0		0		2,000		18,000		3,701,000		2,526,000		10,847,000		7,827,000		88,000		87,000		263,000		262,000		40,000		0		75,000		0		0		0			0		0		21,000		15,000		151,000		15,000		(3,878,000)		(2,649,000)		(11,431,000)		(8,190,000)
Operating Revenues	462,058,000		545,089,000		1,454,365,000		1,492,383,000			134,322,000		93,277,000		378,684,000		267,007,000		77,989,000		71,804,000		202,026,000		196,452,000		53,293,000		47,875,000		160,085,000		135,786,000		27,354,000		24,783,000		79,429,000		66,431,000		9,267,000		14,080,000		27,921,000		64,188,000		145,725,000		279,178,000		27,900,000	562,166,000		718,511,000		17,986,000		16,741,000		55,485,000		52,198,000		(3,878,000)		(2,649,000)		(11,431,000)		(8,190,000)
Costs and Expenses [Abstract]
Operating Expenses	340,947,000		455,442,000		1,128,269,000		1,206,550,000			88,842,000		68,457,000		258,266,000		199,719,000		46,235,000		45,701,000		124,913,000		121,623,000		38,320,000		31,196,000		110,966,000		87,797,000		15,584,000		15,194,000		48,064,000		37,757,000		5,871,000		9,141,000		18,552,000		36,245,000		137,281,000		279,180,000			542,640,000		703,842,000		12,543,000		9,117,000		35,919,000		27,417,000		(3,729,000)		(2,544,000)		(11,051,000)		(7,850,000)
Administrative and general	50,460,000		35,387,000		141,758,000		116,211,000			14,795,000		10,687,000		39,797,000		33,535,000		10,338,000		6,841,000		27,210,000		20,090,000		3,480,000		2,206,000		11,235,000		8,069,000		4,301,000		2,044,000		9,710,000		5,607,000		4,256,000		2,961,000		11,721,000		9,327,000		2,236,000		1,944,000			8,788,000		6,806,000		2,655,000		2,523,000		8,468,000		8,353,000		8,399,000		6,181,000		24,829,000		24,424,000
Depreciation and amortization	45,285,000		36,437,000		128,297,000		114,097,000			16,051,000		11,785,000		44,792,000		36,523,000		10,937,000		9,093,000		31,031,000		33,402,000		7,335,000		6,464,000		21,586,000		17,877,000		5,639,000		5,833,000		16,956,000		16,539,000		483,000		655,000		1,458,000		1,655,000		1,641,000		12,000			4,292,000		37,000		2,345,000		2,129,000		6,407,000		6,655,000		854,000		466,000		1,775,000		1,409,000
Total costs and expenses	436,692,000		527,266,000		1,398,324,000		1,436,858,000			119,688,000		90,929,000		342,855,000		269,777,000		67,510,000		61,635,000		183,154,000		175,115,000		49,135,000		39,866,000		143,787,000		113,743,000		25,524,000		23,071,000		74,730,000		59,903,000		10,610,000		12,757,000		31,731,000		47,227,000		141,158,000		281,136,000			555,720,000		710,685,000		17,543,000		13,769,000		50,794,000		42,425,000		5,524,000		4,103,000		15,553,000		17,983,000
Gains on Asset Dispositions and Impairments Net	9,677,000		10,986,000		19,638,000		28,542,000			6,585,000		5,241,000		9,054,000		13,212,000		613,000		4,894,000		3,455,000		13,260,000		3,503,000		1,303,000		6,288,000		1,978,000		145,000		0		145,000		0		0		7,000		5,000		7,000		0		0			0		0		(1,169,000)		(315,000)		691,000		229,000		0		(144,000)		0		(144,000)
Operating Income	35,043,000		28,809,000		75,679,000		84,067,000			21,219,000		7,589,000		44,883,000		10,442,000		11,092,000		15,063,000		22,327,000		34,597,000		7,661,000		9,312,000		22,586,000		24,021,000		1,975,000		1,712,000		4,844,000		6,528,000		(1,343,000)		1,330,000		(3,805,000)		16,968,000		4,567,000		(1,958,000)			6,446,000		7,826,000		(726,000)		2,657,000		5,382,000		10,002,000		(9,402,000)		(6,896,000)		(26,984,000)		(26,317,000)
Other Income and Expenses [Abstract]
Derivative gains (losses), net	(4,649,000)		(25,954,000)		(5,281,000)		(35,873,000)			0		0		0		0		(188,000)		(807,000)		(492,000)		(1,308,000)		0		0		0		0		0		0		0		0		0		0		0		0		(4,304,000)		(3,063,000)			(3,850,000)		(6,985,000)		0		0		0		0		(157,000)		(22,084,000)		(939,000)		(27,580,000)
Foreign currency gains (losses), net	632,000		(3,126,000)		2,192,000		3,349,000			717,000		(2,129,000)		1,486,000		(1,812,000)		(272,000)		(95,000)		633,000		596,000		33,000		0		(60,000)		0		10,000		(18,000)		16,000		4,000		26,000		17,000		20,000		(41,000)		(183,000)		153,000			(118,000)		132,000		6,000		(75,000)		(17,000)		(98,000)		295,000		(979,000)		232,000		4,568,000
Other Nonoperating Income (Expense)	7,098,000		(39,000)		7,487,000		(273,000)			0		6,000		11,000		6,000		0		0		30,000		0		0		0		0		4,000		4,000		131,000		83,000		187,000		0		0		0		2,000		0		0			0		0		7,141,000		(1,000)		7,349,000		(2,000)		(47,000)		(175,000)		14,000		(470,000)
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	(1,078,000)		9,655,000		1,215,000		10,569,000			1,238,000		8,754,000		4,068,000		9,689,000		219,000		106,000		(5,444,000)		1,061,000		(2,227,000)		2,771,000		(1,538,000)		3,181,000		(551,000)		0		(1,542,000)		0		72,000		0		286,000		0		(1,000)		(2,267,000)			6,153,000		(3,267,000)		172,000		291,000		(768,000)		(95,000)		0		0		0		0
Segment Profit (Loss)										23,174,000		14,220,000		50,448,000		18,325,000		10,851,000		14,267,000		17,054,000		34,946,000		5,467,000		12,083,000		20,988,000		27,206,000		1,438,000		1,825,000		3,401,000		6,719,000		(1,245,000)		1,347,000		(3,499,000)		16,929,000		79,000		(7,135,000)			8,631,000		(2,294,000)		6,593,000		2,872,000		11,946,000		9,807,000
Other Income (Expense) not included in Segment Profit	(10,265,000)		(5,170,000)		(9,291,000)		(21,914,000)
Less Equity Earnings included in Segment Profit	(1,078,000)		9,655,000		1,215,000		10,569,000
Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	27,859,000		(5,480,000)		70,786,000		29,356,000
Capital Expenditures					256,973,000		206,611,000							112,527,000		50,096,000						91,910,000		88,894,000						22,296,000		40,786,000						4,768,000		10,460,000						451,000		36,000							32,000		60,000						21,385,000		13,253,000						3,604,000		3,026,000
Property and Equipment	2,403,221,000		2,031,857,000		2,403,221,000		2,031,857,000		2,150,231,000	822,454,000		610,056,000		822,454,000		610,056,000		777,706,000		650,750,000		777,706,000		650,750,000		378,193,000		361,515,000		378,193,000		361,515,000		198,040,000		233,892,000		198,040,000		233,892,000		1,350,000		805,000		1,350,000		805,000		40,046,000		178,000			40,046,000		178,000		163,454,000		154,081,000		163,454,000		154,081,000		21,978,000		20,580,000		21,978,000		20,580,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	266,589,000		243,678,000		266,589,000		243,678,000		249,753,000	68,003,000		69,272,000		68,003,000		69,272,000		35,755,000		51,395,000		35,755,000		51,395,000		54,250,000		42,870,000		54,250,000		42,870,000		70,413,000		12,340,000		70,413,000		12,340,000		505,000		0		505,000		0		0		9,441,000			0		9,441,000		37,663,000		58,360,000		37,663,000		58,360,000		0		0		0		0
Inventories	77,858,000	[1]	70,623,000		77,858,000	[1]	70,623,000		69,109,000	6,249,000	[1]	4,475,000		6,249,000	[1]	4,475,000		26,590,000	[1]	24,222,000		26,590,000	[1]	24,222,000		2,435,000	[1]	2,149,000		2,435,000	[1]	2,149,000		0	[1]	365,000		0	[1]	365,000		917,000	[1]	448,000		917,000	[1]	448,000		40,134,000	[1]	37,631,000			40,134,000	[1]	37,631,000		1,533,000	[1]	1,333,000		1,533,000	[1]	1,333,000		0	[1]	0		0	[1]	0
Goodwill	57,054,000		54,410,000		57,054,000		54,410,000		57,054,000	13,367,000		13,367,000		13,367,000		13,367,000		352,000		352,000		352,000		352,000		4,345,000		1,743,000		4,345,000		1,743,000		550,000		606,000		550,000		606,000		37,138,000		37,040,000		37,138,000		37,040,000		0		0			0		0		1,302,000		1,302,000		1,302,000		1,302,000		0		0		0		0
Intangible Assets, Net	19,931,000		16,055,000		19,931,000		16,055,000		21,528,000	4,557,000		6,482,000		4,557,000		6,482,000		0		0		0		0		7,996,000		815,000		7,996,000		815,000		1,213,000		1,630,000		1,213,000		1,630,000		5,153,000		6,683,000		5,153,000		6,683,000		681,000		0			681,000		0		331,000		445,000		331,000		445,000		0		0		0		0
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	488,168,000	[2]	448,316,000	[2]	488,168,000	[2]	448,316,000	[2]		155,387,000	[2]	117,011,000	[2]	155,387,000	[2]	117,011,000	[2]	90,169,000	[2]	68,865,000	[2]	90,169,000	[2]	68,865,000	[2]	50,049,000	[2]	54,117,000	[2]	50,049,000	[2]	54,117,000	[2]	4,698,000	[2]	5,163,000	[2]	4,698,000	[2]	5,163,000	[2]	14,544,000	[2]	18,866,000	[2]	14,544,000	[2]	18,866,000	[2]	76,765,000	[2]	89,458,000	[2]		76,765,000	[2]	89,458,000	[2]	50,823,000	[2]	67,791,000	[2]	50,823,000	[2]	67,791,000	[2]	45,733,000	[2]	27,045,000	[2]	45,733,000	[2]	27,045,000	[2]
Total segment assets										1,070,017,000		820,663,000		1,070,017,000		820,663,000		930,572,000		795,584,000		930,572,000		795,584,000		497,268,000		463,209,000		497,268,000		463,209,000		274,914,000		253,996,000		274,914,000		253,996,000		59,607,000		63,842,000		59,607,000		63,842,000		157,626,000		136,708,000			157,626,000		136,708,000		255,106,000		283,312,000		255,106,000		283,312,000
Inventory, Raw Materials																																																		2,900,000					2,900,000
Inventory, Work in Process																																																		700,000					700,000
Cash And Near Cash Assets	601,390,000	[2]	702,400,000	[2]	601,390,000	[2]	702,400,000	[2]
Assets of Disposal Group, Including Discontinued Operation	$ 3,025,000		$ 94,979,000		$ 3,025,000		$ 94,979,000

[1] Inventories for Commodity Trading and Logistics includes raw materials of $2.9 million and work in process of $0.7 million resulting from the acquisition of ICP (see Note 4).

[2] Cash and near cash assets includes cash, cash equivalents, restricted cash, marketable securities, construction reserve funds and Title XI reserve funds.