Seacor (CKH) 10-Q/A 7 Mar 14 2013 Q2 Quarterly report (amended) Financial data

Document_And_Entity_Informatio

Document And Entity Information	6 Months Ended
	Jun. 30, 2013	Jul. 25, 2013
Document Information [Line Items]	'	'
Entity Registrant Name	'SEACOR HOLDINGS INC /NEW/	'
Entity Central Index Key	'0000859598	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Jun-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q2	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	20,230,727
Entity Well-known Seasoned Issuer	'Yes	'
Entity Voluntary Filers	'No	'
Entity Current Reporting Status	'Yes	'

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Jun. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current Assets:	'	'
Cash and cash equivalents	$394,783	$248,204
Restricted cash	16,776	28,285
Marketable securities	27,264	21,668
Receivables:	'	'
Trade, net of allowance for doubtful accounts	188,128	224,944
Other Receivables	37,204	45,334
Inventories	22,955	25,787
Deferred income taxes	3,530	3,530
Prepaid expenses and other	11,715	12,719
Discontinued operations	0	108,153
Total current assets	702,355	718,624
Property and Equipment:	'	'
Property, Plant and Equipment, Gross	2,212,929	2,238,383
Accumulated depreciation	806,672	763,803
Property, Plant and Equipment, Net In Service	1,406,257	1,474,580
Construction in Progress, Gross	133,985	110,296
Net property and equipment	1,540,242	1,584,876
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	293,793	272,535
Construction Reserve Funds & Title XI Reserve Funds	150,375	195,629
Goodwill	17,978	17,978
Intangible Assets, Net	14,594	15,305
Other Assets	48,996	55,123
Discontinued Operations	0	840,724
Total assets	2,768,333	3,700,794
Current Liabilities:	'	'
Current portion of long-term debt	25,109	21,920
Current portion of capital lease obligations	10	2,900
Accounts payable and accrued expenses	73,185	107,892
Other current liabilities	122,424	93,093
Discontinued operations	0	39,836
Total current liabilities	220,728	265,641
Long-Term Debt	674,444	655,309
Capital Lease Obligations	24	59
Deferred Income Taxes	421,623	426,027
Deferred Gains and Other Liabilities	115,078	120,342
Discontinued Operations	0	490,741
Total liabilities	1,431,897	1,958,119
SEACOR Holdings Inc. stockholders’ equity:	'	'
Preferred stock, $.01 par value, 10,000,000 shares authorized; none issued nor outstanding	0	0
Common stock, $.01 par value, 60,000,000 shares authorized; 36,603,406 and 36,444,439 shares issued in 2012 and 2011, respectively	370	367
Additional paid-in capital	1,347,909	1,330,324
Retained earnings	1,056,583	1,473,509
Treasury Stock, Value	1,089,061	1,088,560
Accumulated Other Comprehensive Income (Loss), Net of Tax	-4,243	-1,986
Stockholders' equity attributable to parent, total	1,311,558	1,713,654
Noncontrolling interests in subsidiaries	24,878	29,021
Total equity	1,336,436	1,742,675
Liabilities and stockholders' equity, total	$2,768,333	$3,700,794

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Trade receivables, allowance for doubtful accounts	$1,153	$1,201
Common Stock, Par or Stated Value Per Share	$0.01	$0.01
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	37,035,464	36,740,324
Treasury stock, shares	16,851,335	16,852,391
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Condensed_Consolidated_Stateme

Condensed Consolidated Statements Of Income (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]	'	'	'	'
Operating Revenues	$315,563	$309,225	$582,627	$607,074
Costs and Expenses [Abstract]	'	'	'	'
Operating	240,113	244,545	441,026	452,964
Administrative and general	34,718	36,301	70,363	71,292
Depreciation and amortization	33,783	33,220	67,331	62,922
Total costs and expenses	308,614	314,066	578,720	587,178
Gain (Loss) on Sale of Assets and Asset Impairment Charges	12,305	3,342	14,320	7,119
Operating Income (Loss)	19,254	-1,499	18,227	27,015
Other Income (Expense):	'	'	'	'
Interest income	3,218	7,392	6,385	10,035
Interest expense	7,922	10,012	20,762	19,999
Debt extinguishment losses, net	0	0	0	-160
Marketable security gains, net	6,557	11,596	10,552	14,954
Derivative losses, net	-825	2,554	-2,932	-404
Foreign currency gains, net	-916	-1,024	-4,927	637
Other, net	195	443	198	359
Total Other Nonoperating Income (Expense)	307	10,949	-11,486	5,422
Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	19,561	9,450	6,741	32,437
Income Tax Expense (Benefit)	7,975	3,250	5,322	12,710
Income from Continuing Operations Before Equity in Earnings of 50% or Less Owned Companies	11,586	6,200	1,419	19,727
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	7,710	295	6,841	7,956
Income from Continuing Operations	19,296	6,495	8,260	27,683
Income (Loss) from Discontinued Operations, Net of Tax	0	4,804	-10,325	19,989
Net Income	19,296	11,299	-2,065	47,672
Net Income (Loss) Attributable to Noncontrolling Interest	25	50	-348	-65
Net Income attributable to SEACOR Holdings Inc.	19,271	11,249	-1,717	47,737
Net Income (Loss) attributable to SEACOR Holdings Inc.:	'	'	'	'
Income (Loss) from Continuing Operations Attributable to Parent	19,271	6,445	8,508	27,748
Discontinued operations, net of tax	0	4,804	-10,225	19,989
Net Income attributable to SEACOR Holdings Inc.	$19,271	$11,249	($1,717)	$47,737
Basic Earnings Per Common Share of SEACOR Holdings Inc.	'	'	'	'
Continuing operations	$0.97	$0.31	$0.43	$1.35
Discontinued operations	$0	$0.24	($0.52)	$0.97
Earnings Per Share, Basic	$0.97	$0.55	($0.09)	$2.32
Diluted Earnings Per Common Share of SEACOR Holdings Inc.	'	'	'	'
Continuing operations	$0.91	$0.31	$0.42	$1.33
Discontinued operations	$0	$0.23	($0.51)	$0.96
Earnings Per Share, Diluted	$0.91	$0.54	($0.09)	$2.29
Weighted Average Common Shares Outstanding:	'	'	'	'
Weighted Average Number of Shares Outstanding, Basic	19,825,229	20,584,567	19,782,318	20,552,114
Weighted Average Number of Shares Outstanding, Diluted	24,392,312	20,871,380	20,114,904	20,883,570

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements Of Comprehensive Income (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Net Income	$19,296	$11,299	($2,065)	$47,672
Other Comprehensive Income (Loss):	'	'	'	'
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	-340	-1,415	-4,538	1,785
Reclassification of net foreign currency translation losses to foreign currency gains, net	0	0	0	758
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	331	-195	'	'
Reclassification of net derivative losses on cash flow hedges to interest expense or equity in earnings of 50% or less owned companies	'	'	0	-19
Other	0	0	0	42
Other Comprehensive Income (Loss), before Tax	142	-805	-3,840	3,429
Income tax expense	41	-249	-1,186	1,145
Other Comprehensive Income (Loss), Net of Tax	101	-556	-2,654	2,284
Comprehensive Income	19,397	10,743	-4,719	49,956
Comprehensive Income attributable to Noncontrolling Interests in Subsidiaries	48	-44	-800	92
Comprehensive Income attributable to SEACOR Holdings Inc.	19,349	10,787	-3,919	49,864
Equity Method Investments [Member]	'	'	'	'
Other Comprehensive Income (Loss):	'	'	'	'
Reclassification of net derivative losses on cash flow hedges to interest expense or equity in earnings of 50% or less owned companies	151	145	318	219
Interest Expense [Member]	'	'	'	'
Other Comprehensive Income (Loss):	'	'	'	'
Reclassification of net derivative losses on cash flow hedges to interest expense or equity in earnings of 50% or less owned companies	$0	$660	$0	$1,296

Condensed_Consolidated_Stateme2

Condensed Consolidated Statement Of Changes In Equity (USD $)	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Shares Held In Treasury [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Non-Controlling Interests In Subsidiaries [Member]	Era Group [Member]
In Thousands, unless otherwise specified
Balance at Dec. 31, 2012	$1,742,675	$367	$1,330,324	$1,473,509	($1,088,560)	($1,986)	$29,021	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'
Employee Stock Purchase Plan	978	0	0	0	978	0	0	'
Exercise of stock options	7,830	1	7,829	0	0	0	0	'
Director stock awards	125	0	125	0	0	0	0	'
Restricted stock and restricted stock units	-25	2	-27	0	0	0	0	'
Stockholders' Equity Note, Spinoff Transaction	-415,371	0	0	-415,209	0	-55	-107	'
Stockholders Equity Note Spinoff Transaction, Value, Share Award Settlements for Spin Off	-631	0	-631	0	0	0	0	'
Amortization of share awards	8,810	0	-8,810	0	0	0	0	'
Stock Issued During Period, Value, Restricted Stock Award, Forfeitures	0	0	1,479	0	-1,479	0	0	'
Issuance of noncontrolling interests	40	0	0	0	0	0	40	'
Dividends paid to noncontrolling interests	-3,276	0	0	0	0	0	-3,276	'
Comprehensive income:	'	'	'	'	'	'	'	'
Net Income (Loss) Attributable to Parent	-1,717	0	0	'	0	0	'	'
Net Income (Loss) Attributable to Noncontrolling Interest	-348	'	'	'	'	'	-348	'
Net Income	-2,065	'	'	'	'	'	'	-9,233
Other comprehensive income	-2,654	0	0	0	0	-2,202	-452	'
Balance at Jun. 30, 2013	$1,336,436	$370	$1,347,909	$1,056,583	($1,089,061)	($4,243)	$24,878	'

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements Of Cash Flows (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012
Statement of Cash Flows [Abstract]	'	'
Net Cash Provided by Operating Activities of Continuing Operations	$78,235	$65,293
Cash Flows from Investing Activities of Continuing Operations:	'	'
Purchases of property and equipment	87,931	99,507
Proceeds from disposition of property and equipment	125,432	7,394
Investments in and advances to 50% or less owned companies	26,822	31,906
Return of investments and advances from 50% or less owned companies	8,315	25,641
Net advances on revolving credit line to 50% or less owned companies	0	300
Principal payments on third party notes receivable, net	4,509	18,970
Net increase in restricted cash	-11,509	-2,934
Net (increase) decrease in construction reserve funds and title XI reserve funds	-45,254	-67,554
Repayments on leases, net	1,731	1,793
Businesses acquisitions, net of cash acquired	10,540	148,084
Net cash used in investing activities of continuing operations	71,457	-155,511
Cash Flows from Financing Activities of Continuing Operations:	'	'
Repayments of Debt and Capital Lease Obligations	10,027	64,712
Net borrowings (repayments) on inventory financing arrangements	-2,365	14,798
Proceeds from issuance of long term debt, net of offering costs	6	134
Common stock acquired for treasury	0	17,431
Cash Received (Paid) For Share Settlements from Spinoff Transactions	-357	0
Proceeds and tax benefits from share award plans	8,779	6,659
Cash received from (dividends paid to) noncontrolling interests, net	-3,236	-1,715
Net cash provided by (used in) financing activities of continuing operations	-2,470	-91,863
Effect of Exchange Rate Changes on Cash and Cash Equivalents	-2,565	910
Net Increase (Decrease) in Cash and Cash Equivalents from Continuing Operations	144,657	-181,171
Cash Flows from Discontinued Operations:	'	'
Operating Activities	24,298	76,624
Investing Activities	-8,502	5,715
Financing Activities	-14,017	6,606
Effects of Exchange Rate Changes on Cash and Cash Equivalents	143	595
Net Increase in Cash and Cash Equivalents from Discontinued Operations	1,922	89,540
Net Increase (Decrease) in Cash and Cash Equivalents	146,579	-91,631
Cash and Cash Equivalents, Beginning of Period	248,204	381,482
Cash and Cash Equivalents, End of Period	$394,783	$289,851

Basis_of_Presentation_and_Acco

Basis of Presentation and Accounting Policy	6 Months Ended
	Jun. 30, 2013
Nature Of Operations And Accounting Policies [Abstract]	'
Basis of Presentation and Accounting Policy	'
	BASIS OF PRESENTATION AND ACCOUNTING POLICY
	The condensed consolidated financial information for the three and six months ended June 30, 2013 and 2012 has been prepared by the Company and has not been audited by its independent registered public accounting firm. The condensed consolidated financial statements include the accounts of SEACOR Holdings Inc. and its consolidated subsidiaries. In the opinion of management, all adjustments (consisting of normal recurring adjustments) have been made to fairly present the Company’s financial position as of June 30, 2013, its results of operations for the three and six months ended June 30, 2013 and 2012, its comprehensive income for the three and six months ended June 30, 2013 and 2012, its changes in equity for the six months ended June 30, 2013, and its cash flows for the six months ended June 30, 2013 and 2012. Results of operations for the interim periods presented are not necessarily indicative of operating results for the full year or any future periods.
	Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States have been condensed or omitted. These condensed consolidated financial statements should be read in conjunction with the financial statements and related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.
	Unless the context otherwise indicates, any reference in this Quarterly Report on Form 10-Q to the “Company” refers to SEACOR Holdings Inc. and its consolidated subsidiaries and any reference in this Quarterly Report on Form 10-Q to “SEACOR” refers to SEACOR Holdings Inc.
	Discontinued Operations. On January 31, 2013, the Company completed the spin-off ("Spin-off") of Era Group Inc. (“Era Group”), the company that operated SEACOR's Aviation Services business segment, by means of a dividend to SEACOR's stockholders of all the issued and outstanding common stock of Era Group. Era Group filed a Registration Statement on Form 10 with the Securities and Exchange Commission, describing the Spin-off, that was declared effective on January 14, 2013. Era Group is now an independent company whose common stock is listed on the New York Stock Exchange under the symbol "ERA." Discontinued operations includes the historical financial position, results of operations and cash flows of Era Group as well as the operations previously reported as discontinued in the Company's Annual Report on Form 10-K for the year ended December 31, 2012 (see Note 14).
	Revenue Recognition. The Company recognizes revenue when it is realized or realizable and earned. Revenue is realized or realizable and earned when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price to the buyer is fixed or determinable, and collectability is reasonably assured. Revenue that does not meet these criteria is deferred until the criteria are met. Deferred revenues, included in other current liabilities, for the six months ended June 30 were as follows (in thousands):
		2013				2012
	Balance at beginning of period	$	6,592			$	9,845
	Revenues deferred during the period	—				2,600
	Revenues recognized during the period	—				(5,927		)
	Balance at end of period	$	6,592			$	6,518
	As of June 30, 2013, deferred revenues of $6.6 million were related to the time charter of several offshore support vessels scheduled to be paid through the conveyance of an overriding royalty interest (the "Conveyance") in developmental oil and gas producing properties operated by a customer in the U.S. Gulf of Mexico. Payments under the Conveyance, and the timing of such payments, are contingent upon production and energy sale prices. On August 17, 2012, the customer filed a voluntary petition for Chapter 11 bankruptcy. The Company is vigorously defending its interest in connection with the bankruptcy filing; however, payments received under the Conveyance subsequent to August 17, 2012 are subject to bankruptcy court approval. The Company will continue to recognize revenues as cash is received and approved by the bankruptcy court or earlier should future collection become reasonably assured. All costs and expenses related to these charters were recognized as incurred.
	Accumulated Other Comprehensive Loss. The components of accumulated other comprehensive income (loss) were as follows:
			SEACOR Holdings Inc. Stockholders Equity													Noncontrolling
																Interests
			Foreign				Derivative			Other			Total			Foreign			Other			Other
			Currency				Losses on									Currency						Comprehensive
			Translation				Cash Flow									Translation						Income (Loss)
			Adjustments				Hedges, net									Adjustments
	31-Dec-12		$	(1,238	)		$	(732	)	$	(16	)	$	(1,986	)	$	321		$	(10	)
	Distribution of Era Group stock to shareholders		(55		)		—			—			(55		)	—			—
	Other comprehensive income (loss)		(4,086		)		698			—			(3,388		)	(452		)	—			$	(3,840	)
	Income tax (expense) benefit		1,430				(244		)	—			1,186			—			—			1,186
	Six months ended June 30, 2013		$	(3,949	)		$	(278	)	$	(16	)	$	(4,243	)	$	(131	)	$	(10	)	$	(2,654	)
	Reclassifications. Certain reclassifications of prior period information have been made to conform to the presentation of the current period information. These reclassifications had no effect on net income as previously reported.
	Restatement of Interim Financial Results. In late February 2014, in connection with the Company’s year-end accounting review and preparation of its year-end financial statements, an error was discovered in the accounting for taxes related to the Spin-off of Era Group. The restatement of the Company's unaudited condensed consolidated financial statements in this Amendment No. 1 to the Original Filing is solely related to this error in accounting for taxes, the principal effect of which is an increase in the net loss from discontinued operations for the six months ended June 30, 2013 of $10.1 million (see Note 15).

Fair_Value_Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	FAIR VALUE MEASUREMENTS
	The fair value of an asset or liability is the price that would be received to sell an asset or transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company utilizes a fair value hierarchy that maximizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value and defines three levels of inputs that may be used to measure fair value. Level 1 inputs are quoted prices in active markets for identical assets or liabilities. Level 2 inputs are observable inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly, including quoted prices for similar assets or liabilities in active markets, quoted prices in markets that are not active, inputs other than quoted prices that are observable for the asset or liability, or inputs derived from observable market data. Level 3 inputs are unobservable inputs that are supported by little or no market activity and are significant to the fair value of the assets or liabilities.
	The Company’s financial assets and liabilities as of June 30, 2013 that are measured at fair value on a recurring basis were as follows (in thousands):
		Level 1			Level 2			Level 3
	ASSETS
	Marketable securities(1)	$	27,264		$	—		$	—
	Derivative instruments (included in other receivables)	820			5,961			—
	Construction reserve funds and Title XI reserve funds	150,375			—			—
	LIABILITIES
	Short sale of marketable securities (included in other current liabilities)	7,809			—			—
	Derivative instruments (included in other current liabilities)	703			4,770			—
	______________________
	-1	Marketable security gains, net include unrealized gains of $6.5 million and unrealized losses of $2.0 million for the three months ended June 30, 2013 and 2012, respectively, related to marketable security positions held by the Company as of June 30, 2013. Marketable security gains, net include unrealized gains of $10.5 million for the six months ended June 30, 2013, related to marketable security positions held by the Company as of June 30, 2013. Unrealized gains or losses for the six months ended June 30, 2012, related to marketable security positions held by the Company as of June 30, 2013 were not material.
	The estimated fair values of the Company’s other financial assets and liabilities as of June 30, 2013 were as follows (in thousands):
					Estimated Fair Value
		Carrying			Level 1			Level 2			Level 3
		Amount
	ASSETS
	Cash, cash equivalents and restricted cash	$	411,559		$	411,559		$	—		$	—
	Investments, at cost, in 50% or less owned companies (included in other	9,315			see below
	assets)
	Notes receivable from other business ventures (included in other	21,674			see below
	receivables and other assets)
	LIABILITIES
	Long-term debt, including current portion(1)	699,553			—			813,568			—
	______________________
	-1	The estimated fair value includes the conversion option on the Company's 2.5% Convertible Notes.
	The carrying value of cash, cash equivalents and restricted cash approximates fair value. The fair value of the Company’s long-term debt was estimated based upon quoted market prices or by using discounted cash flow analyses based on estimated current rates for similar types of arrangements. It was not practicable to estimate the fair value of the Company’s investments, at cost, in 50% or less owned companies because of the lack of quoted market prices and the inability to estimate fair value without incurring excessive costs. It was not practicable to estimate the fair value of the Company’s notes receivable from other business ventures as the overall returns are uncertain due to certain provisions for additional payments contingent upon future events. Considerable judgment was required in developing certain of the estimates of fair value and, accordingly, the estimates presented herein are not necessarily indicative of the amounts that the Company could realize in a current market exchange.
	The Company’s non-financial assets and liabilities that were measured at fair value during the six months ended June 30, 2013 were as follows (in thousands):
			Level 1			Level 2			Level 3
	ASSETS
	Long-lived assets under construction(1)		$	17,494		$	—		$	—
	Investment in C-Lift LLC(2)		—			13,290			—
	______________________
	-1	During the six months ended June 30, 2013, the Company recognized impairment charges of $3.0 million related to two of Shipping Services' harbor tugs while under construction, which were sold and leased back upon their completion (see Note 5).
	-2	During the six months ended June 30, 2013, the Company marked its equity investment in C-Lift LLC ("C-Lift") to fair value following its acquisition of a controlling interest (see Note 4). The investment's fair value was determined based on the Company's purchase price of the acquired interest.

Derivative_Instruments_And_Hed

Derivative Instruments And Hedging Strategies	6 Months Ended
	Jun. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments And Hedging Strategies	'
	DERIVATIVE INSTRUMENTS AND HEDGING STRATEGIES
	Derivative instruments are classified as either assets or liabilities based on their individual fair values. Derivative assets and liabilities are included in other receivables and other current liabilities, respectively, in the accompanying condensed consolidated balance sheets. The fair values of the Company’s derivative instruments as of June 30, 2013 were as follows (in thousands):
		Derivative			Derivative
		Asset			Liability
	Options on equities and equity indices	$	415		$	—
	Forward currency exchange, option and future contracts	298			390
	Interest rate swap agreements	—			4,271
	Commodity swap, option and future contracts:
	Exchange traded	554			703
	Non-exchange traded	5,514			109
		$	6,781		$	5,473
	Cash Flow Hedges. As of June 30, 2013, the Company had no interest rate swap agreements designated as cash flow hedges. As of June 30, 2013, one of the Company’s Offshore Marine Services 50% or less owned companies had an interest rate swap agreement maturing in 2015 that has been designated as a cash flow hedge. This instrument calls for the joint venture to pay a fixed interest rate of 1.48% on the amortized notional value of $17.5 million and receive a variable interest rate based on LIBOR on the amortized notional value. As of June 30, 2013, one of the Company’s Inland River Services 50% or less owned companies had four interest rate swap agreements with maturities ranging from 2013 through 2015 that have been designated as cash flow hedges. These instruments call for the joint venture to pay fixed rates of interest ranging from 1.53% to 4.16% on the aggregate amortized notional value of $38.8 million and receive a variable interest rate based on LIBOR on the aggregate amortized notional value. Additionally, as of June 30, 2013, one of the Company’s Shipping Services 50% or less owned companies had an interest rate swap agreement maturing in 2017 that has been designated as a cash flow hedge. The instrument calls for the joint venture to pay a fixed interest rate of 2.79% on the amortized notional value of $38.4 million and received a variable interest rate based on LIBOR on the amortized notional value. By entering into these interest rate swap agreements, the Company's joint ventures have converted the variable LIBOR component of certain of their outstanding borrowings to a fixed interest rate.
	The Company recognized gains (losses) on derivative instruments designated as cash flow hedges for the six months ended June 30 as follows (in thousands):
		2013			2012
	Interest rate swap agreements, effective portion in other comprehensive income (loss)	$	380		$	(671	)
	Interest rate swap agreements, ineffective portion in derivative gains (losses), net	—			(19		)
		$	380		$	(690	)
	Other Derivative Instruments. The Company recognized gains (losses) on derivative instruments not designated as hedging instruments in derivative gains (losses), net for the six months ended June 30 as follows (in thousands):
		2013			2012
	Options on equities and equity indices	$	(3,012	)	$	(910	)
	Forward currency exchange, option and future contracts	(592		)	373
	Interest rate swap agreements	237			(237		)
	Commodity swap, option and future contracts:
	Exchange traded	(821		)	(1,863		)
	Non-exchange traded	1,256			2,252
		$	(2,932	)	$	(385	)
	The Company, from time to time, holds positions in publicly traded equity options that convey the right or obligation to engage in a future transaction on the underlying equity security or index. The Company’s investment in equity options primarily includes positions in energy, marine, transportation and other related businesses. These contracts are typically entered into to mitigate the risk of changes in the market value of marketable security positions that the Company is either about to acquire, has acquired or is about to dispose of.
	The Company enters and settles forward currency exchange, option and future contracts with respect to various foreign currencies. As of June 30, 2013, the outstanding forward currency exchange contracts translated into a net purchase of foreign currencies with an aggregate U.S. dollar equivalent of $13.1 million. These contracts enable the Company to buy currencies in the future at fixed exchange rates, which could offset possible consequences of changes in currency exchange rates with respect to the Company’s business conducted outside of the United States. The Company generally does not enter into contracts with forward settlement dates beyond twelve to eighteen months.
	The Company has entered into various interest rate swap agreements with maturities ranging from 2013 through 2018 that call for the Company to pay fixed interest rates ranging from 2.25% to 3.05% on an aggregate amortized notional value of $221.1 million (including an amortized notional value of €10.9 million or $14.4 million) and receive a variable interest rate based on LIBOR on these notional values. In addition, one of the Company’s Offshore Marine Services 50% or less owned companies has entered into an interest rate swap agreement maturing in 2018 that calls for the joint venture to pay a fixed interest rate of 1.30% on the amortized notional value of $108.0 million and receive a variable interest rate based on LIBOR on the amortized notional value. The general purpose of these interest rate swap agreements is to provide protection against increases in interest rates, which might lead to higher interest costs for the Company or its joint venture.
	The Company enters and settles positions in various exchange and non-exchange traded commodity swap, option and future contracts. The Company's ethanol and industrial alcohol manufacturing facility enters into exchange traded positions (primarily corn) to protect its raw material and finished goods inventory balance from market changes. In the Company’s agricultural trading business, fixed price future purchase and sale contracts for sugar are included in the Company’s non-exchange traded derivative positions. The Company enters into exchange traded positions to protect these purchase and sale contracts as well as its inventory balances from market changes. As of June 30, 2013, the net market exposure to corn and sugar under these contracts was not material. The Company also enters into exchange traded positions (primarily natural gas, heating oil, crude oil, gasoline, corn and sugar) to provide value to the Company should there be a sustained decline in the price of commodities that could lead to a reduction in the market values and cash flows of the Company’s Offshore Marine Services, Inland River Services and Shipping Services businesses. As of June 30, 2013, these positions were not material.

Business_Acquisitions

Business Acquisitions	6 Months Ended
	Jun. 30, 2013
Business Combinations [Abstract]	'
Business Acquisitions	'
	BUSINESS ACQUISITIONS
	C-Lift Acquisition. On June 6, 2013, the Company acquired a 100% controlling interest in C-Lift through the acquisition of its partner's 50% interest for $12.7 million in cash subject to certain working capital adjustments (see Note 6). C-Lift owns and operates two liftboats in the U.S. Gulf of Mexico. The Company performed a fair value analysis and the purchase price was allocated to the acquired assets and liabilities based on their fair values resulting in no goodwill being recorded. The preliminary fair value analysis is pending completion of a final valuation for the acquired assets and liabilities.
	Pantagro Acquisition. On June 25, 2012, the Company acquired a 95% controlling interest in Pantagro-Pantanal Produtos Agropecuarious Ltda. ("Pantagro") for $0.4 million ($0.2 million in cash and $0.2 million in a note payable). Pantagro is an Argentine agricultural trading company focusing primarily on salt. The Company performed a fair value analysis and the purchase price was allocated to the acquired assets and liabilities based on their fair values resulting in no goodwill being recorded. The fair value analysis was finalized in March 2013.
	Superior Lift Boats Acquisition. On March 30, 2012, the Company acquired 18 lift boats, real property and working capital from Superior Energy Inc. (“Superior”) for $142.5 million. The Company performed a fair value analysis and the purchase price was allocated to the acquired assets and liabilities based on their fair values resulting in no goodwill being recorded. The fair value analysis was finalized in March 2013.
	Purchase Price Allocation. The following table summarizes the allocation of the purchase price for the Company’s business acquisitions during the six months ended June 30, 2013 (in thousands):
	Trade and other receivables	$	3,250
	Other current assets	32
	Investments, at Equity, and Advances to 50% or Less Owned Companies	(13,290		)
	Property and Equipment	43,521
	Intangible Assets	1,599
	Accounts payable	(264		)
	Other current liabilities	(1,640		)
	Long-Term Debt	(22,668		)
	Purchase price(1)	$	10,540
	______________________
	-1	Purchase price is net of cash acquired of $2.2 million.

Equipment_Acquisitions_Disposi

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies	6 Months Ended
	Jun. 30, 2013
Equipment Acquisitions, Dispositions And Depreciation And Impairment Policies [Abstract]	'
Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies	'
	EQUIPMENT ACQUISITIONS, DISPOSITIONS AND DEPRECIATION AND IMPAIRMENT POLICIES
	During the six months ended June 30, 2013, capital expenditures were $87.9 million. Equipment deliveries during the period included one specialty offshore support vessel, two liftboats, two wind farm utility vessels, two liquid tank barges and three U.S.-flag harbor tugs.
	During the six months ended June 30, 2013, the Company sold two crew boats, one mini-supply vessel, one supply vessel, one specialty offshore support vessel, three liftboats, sixteen dry-cargo barges, eight liquid tank barges, two U.S.-flag harbor tugs and other property and equipment for net proceeds of $132.4 million ($125.1 million in cash, $0.2 million in vendor credits and $7.1 million in seller financing) and gains of $15.2 million, of which $12.9 million were recognized currently and $2.3 million were deferred. In addition, the Company recognized previously deferred gains of $1.4 million. The specialty offshore support vessel and the supply vessel were sold to certain of the Company's Offshore Marine Services' joint ventures for $60.5 million (see Note 6). During the six months ended June 30, 2013, the Company also received $0.3 million in deposits on future equipment sales.
	The Company has sold certain equipment to 50% or less owned companies, entered into vessel sale-leaseback transactions with finance companies, and provided seller financing on sales of its equipment to third parties and its 50% or less owned companies. A portion of the gains realized from these transactions were deferred and recorded in deferred gains and other liabilities in the accompanying condensed consolidated balance sheets. Deferred gain activity related to these transactions for the six months ended June 30 was as follows (in thousands):
		2013			2012
	Balance at beginning of period	$	111,514		$	117,192
	Deferred gains arising from asset sales	2,289			7,280
	Amortization of deferred gains included in operating expenses as a reduction to rental expense	(5,192		)	(9,526		)
	Amortization of deferred gains included in gains on asset dispositions and impairments, net	(1,431		)	(2,039		)
	Balance at end of period	$	107,180		$	112,907
	Equipment, stated at cost, is depreciated using the straight-line method over the estimated useful life of the asset to an estimated salvage value. With respect to each class of asset, the estimated useful life is based upon a newly built asset being placed into service and represents the point at which it is typically not justifiable for the Company to continue to operate the asset in the same or similar manner. From time to time, the Company may acquire older assets that have already exceeded the Company’s useful life policy, in which case the Company depreciates such assets based on its best estimate of remaining useful life, typically the next survey or certification date.
	As of June 30, 2013, the estimated useful life (in years) of each of the Company’s major categories of new equipment was as follows:
	Offshore support vessels (excluding wind farm utility)	20
	Wind farm utility vessels	10
	Inland river dry cargo and deck barges	20
	Inland river liquid tank barges	25
	Inland river towboats	25
	U.S.-flag product tankers	25
	RORO(1) vessels	20
	Harbor tugs	25
	Ocean liquid tank barges	25
	Terminal and manufacturing facilities	20
	______________________
	-1	Roll on/Roll off ("RORO").
	The Company performs an impairment analysis of long-lived assets used in operations, including intangible assets, when indicators of impairment are present. If the carrying value of the assets is not recoverable, as determined by the estimated undiscounted cash flows, the carrying value of the assets is reduced to fair value. Generally, fair value is determined using valuation techniques, such as expected discounted cash flows or appraisals, as appropriate. During the six months ended June 30, 2013, the Company recognized impairment charges of $3.0 million related to two of Shipping Services' harbor tugs while under construction, which were sold and leased back upon their completion.

Investments_At_Equity_And_Adva

Investments, At Equity, And Advances To 50% Or Less Owned Companies	6 Months Ended
	Jun. 30, 2013
Equity Method Investment, Summarized Financial Information [Abstract]	'
Investments, At Equity, And Advances To 50% Or Less Owned Companies	'
	INVESTMENTS, AT EQUITY, AND ADVANCES TO 50% OR LESS OWNED COMPANIES
	C-Lift. C-Lift was a 50-50 joint venture established to construct and operate liftboats. On June 6, 2013, the Company acquired a 100% controlling interest in C-Lift through its acquisition of its partner's 50% interest for $12.7 million in cash subject to certain working capital adjustments (see Note 4). Upon the acquisition, the Company adjusted its investment in C-Lift to fair value resulting in the recognition of a gain of $4.2 million, net of tax, which is included in equity in earnings of 50% or less owned companies in the accompanying condensed consolidated statements of income.
	Sea-Cat Crewzer II. On January 23, 2013 the Company and another offshore support vessel operator formed Sea-Cat Crewzer II LLC (“Sea-Cat Crewzer II”), a 50-50 joint venture to own and operate two high speed offshore catamaran crew boats. Upon formation, the Company and its partner each contributed capital of $11.5 million in cash. Sea-Cat Crewzer II then immediately purchased one high speed offshore catamaran crew boat from the Company for $24.1 million ($23.0 million in cash and $1.1 million in seller financing).
	MexMar. During the six months ended June 30, 2013, the Company made an additional cash investment of $5.9 million in Mantenimiento Express Maritimo, S.A.P.I. de C.V. ("MexMar"), an Offshore Marine Services Mexican joint venture. During the six months ended June 30, 2013, MexMar purchased one offshore support vessel from the Company for $36.4 million ($30.4 million in cash and $6.0 million in seller financing). During the six months ended June 30, 2013, MexMar repaid the $6.0 million of seller financing and the Company provided an additional $1.7 million advance for the purchase of another offshore support vessel.
	SCFCo Holdings. SCFCo Holdings LLC (“SCFCo”) was established to operate towboats and dry cargo barges on the Parana-Paraguay Rivers and a terminal facility at Port Ibicuy, Argentina. During the six months ended June 30, 2013, the Company contributed additional capital of $2.9 million to fund SCFCo’s operations, provided net temporary working capital advances of $1.8 million and received working capital repayments of $1.8 million. As of June 30, 2013, the total outstanding balance of working capital advances was $2.3 million.
	Bunge-SCF Grain. Bunge-SCF Grain LLC (“Bunge-SCF Grain”) was established to construct and operate a terminal grain elevator in Fairmont City, Illinois. During the six months ended June 30, 2013, the Company and its partner each made a working capital advance of $2.5 million to Bunge-SCF Grain and received $0.5 million of repayments on working capital advances. As of June 30, 2013, the total outstanding balance of working capital advances was $7.0 million.
	Witt O'Brien's. During the six months ended June 30, 2013, the Company received dividends of $1.2 million from Witt O'Brien's LLC.
	Other. During the six months ended June 30, 2013, the Company made a $0.5 million capital contribution to one of its industrial aviation businesses in Asia and received dividends of $0.4 million from certain offshore marine services joint ventures.
	Subsequent to June 30, 2013, the Company contributed $42.1 million in net cash and other consideration valued at $14.9 million that included certain progress payments made toward the construction of two Liquefied Petroleum Gas tankers (Very Large Gas Carriers, otherwise known as "VLGC's"), the construction contracts for the two VLGC's and the related options to construct additional VLGC's to Dorian LPG Ltd. in exchange for a noncontrolling ownership interest.
	Guarantees. The Company has guaranteed the payment of amounts owed by one of its joint ventures under a vessel charter and has guaranteed amounts owed under banking facilities by certain of its joint ventures. As of June 30, 2013, the total amount guaranteed by the Company under these arrangements was $14.9 million. In addition, as of June 30, 2013, the Company had uncalled capital commitments to two of its joint ventures for a total of $2.4 million.

Commitments_And_Contingencies

Commitments And Contingencies	6 Months Ended
	Jun. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments And Contingencies	'
	COMMITMENTS AND CONTINGENCIES
	As of June 30, 2013, the Company’s unfunded capital commitments were $150.1 million and included: 17 offshore support vessels for $128.2 million; two inland river liquid tank barges for $2.9 million; five inland river towboats for $10.9 million; one U.S.-flag harbor tug for $1.6 million and other equipment and improvements for $6.5 million. Of these commitments, $55.6 million is payable during the remainder of 2013 with the balance payable through 2015. These unfunded capital commitments exclude $139.4 million related to two VLGC's that the Company's Shipping Services business segment committed to construct during the six months ended June 30, 2013. Subsequent to June 30, 2013, the Company contributed $42.1 million in net cash and other consideration valued at $14.9 million that included certain progress payments made toward the construction of the two VLGC's, the construction contracts for the VLGC's and the related options to construct additional VLGC's to Dorian LPG Ltd. in exchange for a noncontrolling ownership interest (see Note 6).
	On July 14, 2010, a group of individuals and entities purporting to represent a class commenced a civil action in the U.S. District Court for the Eastern District of Louisiana, Terry G. Robin, et al. v. Seacor Marine, L.L.C., et al., No. 2:10-CV-01986 (E.D. La.) (the “Robin Case”), in which they asserted that support vessels, including vessels owned by the Company, responding to the explosion and resulting fire that occurred aboard the semi-submersible drilling rig, the Deepwater Horizon, were negligent in their efforts to save lives and put out the fire and contributed to the sinking of the Deepwater Horizon and subsequent oil spill. The action was part of the overall multi-district litigation, In re Oil Spill by the Oil Rig “Deepwater Horizon”, MDL No. 2179 (“MDL”). The complaint sought compensatory, punitive, exemplary, and other damages. In response to this lawsuit, the Company filed petitions seeking exoneration from, or limitation of liability in relation to, any actions that may have been taken by vessels owned by the Company to extinguish the fire. On June 8, 2011, the Company moved to dismiss these claims (with the exception of one claim filed by a Company employee) on various legal grounds. On October 12, 2011, the Court granted the Company's motion to dismiss in its entirety, dismissing with prejudice all claims that had been filed against the Company in the limitation actions (with the exception of one claim filed by a Company employee that was not subject to the motion to dismiss). The Court entered final judgments in favor of the Company in the Robin Case and each of the limitation actions on November 21, 2011. On December 12, 2011, the claimants appealed each of those judgments to the U.S. Court of Appeals for the Fifth Circuit ("Fifth Circuit"). The claimants' opening brief was submitted on May 7, 2012, and the claimants filed a reply brief on June 1, 2012. Oral argument was not requested by the Fifth Circuit. On December 13, 2012, the Fifth Circuit affirmed the judgment of the district court. The claimants have not petitioned the United States Supreme Court for a writ of certiorari and their deadline to do so has expired.
	With respect to the one claim filed by a Company employee, that individual also commenced a separate action in the MDL entitled DuWayne Mason v. Seacor Marine, LLC, No. 2:11-CV-00826 (E.D. La.), in which he alleges sustaining personal injuries not only in connection with responding to the explosion and fire, but also in the months thereafter in connection with the clean-up of oil and dispersants while a member of the crew of the M/V Seacor Vanguard. Although the case is subject to the MDL Court's stay of individual proceedings, on July 16, 2012 the employee sought to sever his case from the MDL. On March 5, 2013, the Court denied the motion, and on April 2, 2013, the employee filed a motion asking the Court to reconsider. The Company filed its response opposing the employee's motion on April 30, 2013, and on May 3, 2013, the Court denied the motion.  On May 22, 2013, the employee filed a Notice of Appeal to the Fifth Circuit.  On July 24, 2013, the Company filed a motion to dismiss for lack of appellate jurisdiction. The Company intends to vigorously defend the action should it ever proceed and the responsible party has agreed, subject to certain potential limitations, to indemnify and defend the Company in connection with this matter. Although the Company is unable to estimate the potential exposure, if any, resulting from this matter, the Company does not expect it will have a material effect on the Company's consolidated financial position or its results of operations.
	On July 20, 2010, two individuals purporting to represent a class commenced a civil action in the Civil District Court for the Parish of Orleans in the State of Louisiana, John Wunstell, Jr. and Kelly Blanchard v. BP, et al., No. 2010-7437 (Division K) (the “Wunstell Action”), in which they assert, among other theories, that Mr. Wunstell suffered injuries as a result of his exposure to certain noxious fumes and chemicals in connection with the provision of remediation, containment and response services by O'Brien's Response Management Inc. ("ORM"), a subsidiary of the Company prior to the ORM Transaction (as defined in the Company's Annual Report on Form 10-K for the year ended December 31, 2012). The action now is part of the overall MDL. The complaint also seeks to establish a “class-wide court-supervised medical monitoring program” for all individuals “participating in BP's Deepwater Horizon Vessels of Opportunity Program and/or Horizon Response Program” who allegedly experienced injuries similar to those of Mr. Wunstell. The Company believes this lawsuit has no merit and will continue to vigorously defend the action and pursuant to contractual agreements with the responsible party, the responsible party has agreed, subject to certain potential limitations, to indemnify and defend ORM in connection with the Wunstell Action and claims asserted in the MDL, discussed further below. Although the Company is unable to estimate the potential exposure, if any, resulting from this matter, the Company does not expect it will have a material effect on the Company's consolidated financial position or its results of operations.
	On December 15, 2010, ORM and National Response Corporation ("NRC"), subsidiaries of the Company prior to the ORM Transaction and SES Business Transaction (as defined in the Company's Annual Report on Form 10-K for the year ended December 31, 2012), respectively, were named as defendants in one of the several consolidated “master complaints” that have been filed in the overall MDL. The master complaint naming ORM and NRC asserts various claims on behalf of a putative class against multiple defendants concerning the clean-up activities generally, and the use of dispersants specifically. By court order, the Wunstell Action has been stayed as a result of the filing of the referenced master complaint. The Company believes that the claims asserted against ORM and NRC in the master complaint have no merit and on February 28, 2011, ORM and NRC moved to dismiss all claims against them in the master complaint on legal grounds. On September 30, 2011, the Court granted in part and denied in part the motion to dismiss that ORM and NRC had filed (an amended decision was issued on October 4, 2011 that corrected several grammatical errors and non-substantive oversights in the original order). Although the Court refused to dismiss the referenced master complaint in its entirety at that time, the Court did recognize the validity of the “derivative immunity” and “implied preemption” arguments that ORM and NRC advanced and directed ORM and NRC to (i) conduct limited discovery to develop evidence to support those arguments and (ii) then re-assert the arguments. The Court did, however, dismiss all state-law claims and certain other claims that had been asserted in the referenced master complaint, and dismissed the claims of all plaintiffs that have failed to allege a legally-sufficient injury. A schedule for limited discovery and motion practice was established by the Court and, in accordance with that schedule, ORM and NRC filed for summary judgment re-asserting their derivative immunity and implied preemption arguments on May 18, 2012. Those motions were argued on July 13, 2012 and are still pending decision. In addition to the indemnity provided to ORM, pursuant to contractual agreements with the responsible party, the responsible party has agreed, subject to certain potential limitations, to indemnify and defend ORM and NRC in connection with these claims in the MDL. Although the Company is unable to estimate the potential exposure, if any, resulting from this matter, the Company does not expect it will have a material effect on the Company's consolidated financial position or its results of operations.
	Subsequent to the filing of the referenced master complaint, nine additional individual civil actions have been filed in or removed to the U.S. District Court for the Eastern District of Louisiana concerning the clean-up activities generally, which name the Company, ORM and/or NRC as defendants or third-party defendants and are part of the overall MDL. On April 8, 2011, ORM was named as a defendant in Johnson Bros. Corporation of Louisiana v. BP, PLC, et al., No. 2:11-CV-00781 (E.D. La.), which is a suit by an individual business seeking damages allegedly caused by a delay on a construction project alleged to have resulted from the clean-up operations. On April 15, 2011, ORM and NRC were named as defendants in James and Krista Pearson v. BP Exploration & Production, Inc. ("BP Exploration"), et al., No. 2:11-CV-00863 (E.D. La.), which is a suit by a husband and wife, who allegedly participated in the clean-up effort and are seeking damages for personal injury, property damage to their boat, and amounts allegedly due under contract. On April 15, 2011, ORM and NRC were named as defendants in Thomas Edward Black v. BP Exploration, et al., No. 2:11-CV-00867 (E.D. La.), which is a suit by an individual who is seeking damages for lost income because he allegedly could not find work in the fishing industry after the oil spill. On April 20, 2011, a complaint was filed in Darnell Alexander, et al. v. BP, PLC, et al., No. 2:11-CV-00951 (E.D. La.) on behalf of 117 individual plaintiffs that seek to adopt the allegations made in the referenced master complaint against ORM and NRC (and the other defendants). Plaintiffs in this matter have been since been granted leave to amend their complaint to include 410 additional individual plaintiffs. On October 3, 2012, ORM and NRC were served with a Rule 14(c) Third-Party Complaint by Jambon Supplier II, L.L.C. and Jambon Marine Holdings L.L.C. in their Limitation of Liability action, In the Matter of Jambon Supplier II, L.L.C., et al., No. 2:12-CV-00426 (E.D. La.). This Third-Party Complaint alleges that if claimant David Dinwiddie, who served as a clean-up crewmember aboard the M/V JAMBON SUPPLIER II vessel during the clean-up efforts, was injured as a result of his exposure to dispersants and chemicals during the course and scope of his employment, then said injuries were caused by the third-party defendants. On November 25, 2012, ORM was named as a defendant in Victoria Sanchez v. American Pollution Control Corp. et al., No. 2:12-CV-00164 (E.D. La.), a maritime suit filed by an individual who allegedly participated in the clean-up effort and sustained personal injuries during the course of such employment. On December 17, 2012, the Court unsealed a False Claims Act lawsuit naming ORM as a defendant, Dillon v. BP, PLC et al., No. 2:12-CV-00987 (E.D. La.)., which is a suit by an individual seeking damages and penalties arising from alleged false reports and claims made to the federal government with respect to the amount of oil burned and dispersed during the clean-up. The federal government has declined to intervene in this suit. On April 8, 2013, the Company, ORM, and NRC were named as defendants in William and Dianna Fitzgerald v. BP Exploration et al., No. 2:13-CV-00650 (E.D. La.), which is a suit by a husband and wife whose son allegedly participated in the clean-up effort and became ill as a result of his exposure to oil and dispersants. Finally, on April 17, 2013, ORM was named as a defendant in Danos et al. v. BP America Production Co. et al., No. 2:13-CV-03747 (removed to E.D. La.), which is a suit by eight individuals seeking damages for dispersant exposure either as a result of their work during clean-up operations or as a result of their residence in the Gulf. By court order, all nine of these additional individual cases have been stayed until further notice. The Company is unable to estimate the potential exposure, if any, resulting from these matters but believes they are without merit and does not expect that they will have a material effect on its consolidated financial position or its results of operations.
	On February 18, 2011, Triton Asset Leasing GmbH, Transocean Holdings LLC, Transocean Offshore Deepwater Drilling Inc., and Transocean Deepwater Inc. (collectively “Transocean”) named ORM and NRC as third-party defendants in a Rule 14(c) Third-Party Complaint in Transocean's own Limitation of Liability Act action, which is part of the overall MDL, tendering to ORM and NRC the claims in the referenced master complaint that have already been asserted against ORM and NRC. Transocean, Cameron International Corporation, Halliburton Energy Services, Inc., and M-I L.L.C. also filed cross-claims against ORM and NRC for contribution and tort indemnity should they be found liable for any damages in Transocean's Limitation of Liability Act action and ORM and NRC have asserted counterclaims against those same parties for identical relief. Weatherford U.S., L.P. and Weatherford International, Inc. (collectively "Weatherford") had also filed cross-claims against ORM and NRC, but recently moved to voluntarily dismiss these cross-claims without prejudice. The Court granted Weatherford's motion on February 8, 2013. As indicated above, the Company is unable to estimate the potential exposure, if any, resulting from these actions but believes they are without merit and does not expect that these matters will have a material effect on its consolidated financial position or its results of operations.
	On November 16, 2012, 668 individuals who served as beach clean-up workers in Escambia County, Florida during the Deepwater Horizon oil spill response commenced a civil action in the Circuit Court for the First Judicial Circuit of Florida, in and for Escambia County, Abney et al. v. Plant Performance Services, LLC et al., No. 2012-CA-002947, in which they allege, among other things, that ORM and other defendants engaged in the contamination of Florida waters and beaches in violation of Florida Statutes Chapter 376 and injured the plaintiffs by exposing them to dispersants during the course and scope of their employment. The case was removed to the U.S. District Court for the Northern District of Florida on January 13, 2013, Abney et al. v. Plant Performance Services, LLC et la., No. 3:13-CV-00024 (N.D. Fla.), and on January 16, 2013, the United States Judicial Panel on Multidistrict Litigation (“JPML”) issued a Conditional Transfer Order (“CTO”) transferring the case to the MDL, subject to any timely-filed notice of objection from the plaintiffs. Upon receipt of a notice of objection from the plaintiffs, a briefing schedule was set by the JPML, and so a stay of proceedings and suspension of deadlines was sought and obtained by the Court in the U.S. District Court for the Northern District of Florida. Following briefing before the JPML, the case was transferred to the U.S. District Court for the Eastern District of Louisiana and consolidated with the MDL on April 2, 2013. On April 22, 2013, a companion case to this matter was filed in the U.S. District Court for the Northern District of Florida, Abood et al. v. Plant Performance Services, LLC et al., No. 3:13-CV-00284 (N.D. Fla.), which alleges identical allegations against the same parties but names an additional 174 plaintiffs, all of whom served as clean-up workers in various Florida counties during the Deepwater Horizon oil spill response.  A CTO was issued by the JPML on May 2, 2013, no objection was filed by the plaintiffs, and the case was transferred to the U.S. District Court for the Eastern District of Louisiana and consolidated with the MDL on May 10, 2013.  By court order, both of these matters have been stayed until further notice. The Company is unable to estimate the potential exposure, if any, resulting from these matters but believes they are without merit and does not expect that these matters will have a material effect on its consolidated financial position or its results of operations.
	Separately, on March 2, 2012, the Court announced that BP Exploration and BP America Production Company ("BP America") (collectively "BP") and the plaintiffs had reached an agreement on the terms of two proposed class action settlements that will resolve, among other things, plaintiffs' economic loss claims and clean-up related claims against BP. The parties filed their proposed settlement agreements on April 18, 2012 along with motions seeking preliminary approval of the settlements. The Court held a hearing on April 25, 2012 to consider those motions and preliminarily approved both settlements on May 2, 2012. A final fairness hearing took place on November 8, 2012. The Court granted final approval to the Economic and Property Damages Class Action Settlement on December 21, 2012, and granted final approval to the Medical Benefits Class Action Settlement on January 11, 2013. Both class action settlements are currently on appeal to the Fifth Circuit. Although neither the Company, ORM, or NRC are parties to the settlement agreements, the Company, ORM, and NRC are listed as released parties on the releases accompanying both settlement agreements. As the releases for both settlements have been deemed valid and enforceable by the district court, if the Fifth Circuit affirms these decisions, class members who did not file timely requests for exclusion will be barred from pursuing economic loss, property damage, personal injury, medical monitoring, and/or other released claims against the Company, ORM, and NRC. At this time, the Company expects these settlements to reduce ORM's potential exposure, if any, from some of the pending actions described above, and continues to evaluate the settlements' impacts on these cases.
	On January 29, 2013, HEPACO, LLC ("HEPACO"), served a demand for arbitration upon ORM, in which HEPACO claims that ORM owes HEPACO an additional fee of $20,291,178.92 under the parties' Management Services Agreement (“MSA”), dated June 1, 2010.  According to HEPACO, the MSA requires ORM to pay HEPACO an additional fee of 30% of total charges paid under the MSA ("Surcharge") to compensate HEPACO for U.S. Longshoremen's and Harbor Workers' insurance or Jones Act insurance and related risks attendant to the work when contract requires labor to be performed over, adjoining and/or in water. ORM denies liability for the Surcharge, intends to vigorously defend against the claim, and has sought indemnity for any resulting judgment and related attorneys fees from BP America and BP Exploration. ORM has advised BP that, pursuant to the Bridge Agreement HOU-WL4-3066 between BP and ORM, effective as of June 1, 2010, under which ORM managed and oversaw, for BP, subcontractors, such as HEPACO, in connection with on-shore services related to the BP Deepwater Horizon oil spill, BP ultimately is responsible for the payment of the Surcharge should HEPACO be determined to be entitled to recover it under the MSA.
	ORM is defending against three collective action lawsuits, each asserting failure to pay overtime with respect to individuals who provided service on the Deepwater Horizon spill response (the “DPH FLSA Actions”) under the Fair Labor Standards Act (“FLSA”).  These cases - Dennis Prejean v. O'Brien's Response Management Inc. (E.D. La., Case No.: 2:12-cv-01045) (the “Prejean Action”); Baylor Singleton et. al. v. O'Brien's Response Management Inc. et. al. (E.D. La., Case No.: 2:12-cv-01716) (the “Singleton Action”); and Himmerite et al. v. O'Brien's Response Management Inc. et al. (E.D. La., Case No.: 2:12-cv-01533) (the “Himmerite Action”) - were each brought on behalf of certain individuals who worked on the Deepwater Horizon oil spill response and who were classified as independent contractors.  The Prejean, Himmerite and Singleton Actions were each filed in the United States District Court for the Eastern District of Louisiana and then subsequently consolidated with the overall MDL.  The Himmerite and Singleton Actions have since been automatically stayed pending further scheduling by the Court, pursuant to the procedures in the MDL.  In the Prejean Action, ORM has answered the complaint, a scheduling order has been issued, and plaintiffs have, among other things, filed a Motion for Conditional Certification to which ORM's response is due by August 22, 2013.  The limitations periods for potential plaintiffs to opt-in to the Prejean, Himmerite and Singleton actions have all been tolled pending further action by the Court.  The Company is unable to estimate the potential exposure, if any, resulting from any of these DPH FLSA Actions, but believes they are without merit and will continue to vigorously defend against them.
	In the course of the Company's business, it may agree to indemnify the counterparty to an agreement.  If the indemnified party makes a successful claim for indemnification, the Company would be required to reimburse that party in accordance with the terms of the indemnification agreement.  Indemnification agreements generally are subject to threshold amounts, specified claim periods and other restrictions and limitations.
	In connection with the SES Business Transaction and the ORM Transaction, the Company remains contingently liable for certain indemnification obligations, including potential liabilities relating to work performed in connection with the Deepwater Horizon oil spill response. In the case of the SES Business Transaction, such potential liabilities may not exceed the purchase consideration received by the Company for the SES Business Transaction and in the case of the ORM Transaction, are subject to a negotiated cap. The Company currently is indemnified under contractual agreements with BP with respect to such potential liabilities.
	In the normal course of its business, the Company becomes involved in various other litigation matters including, among other things, claims by third parties for alleged property damages and personal injuries. Management has used estimates in determining the Company's potential exposure to these matters and has recorded reserves in its financial statements related thereto where appropriate. It is possible that a change in the Company's estimates of that exposure could occur, but the Company does not expect such changes in estimated costs would have a material effect on the Company's consolidated financial position or its results of operations.

Multiemployer_Pension_Plans

Multiemployer Pension Plans	6 Months Ended
	Jun. 30, 2013
Compensation and Retirement Disclosure [Abstract]	'
Multiemployer Pension Plans	'
	MULTI-EMPLOYER PENSION PLANS
	During the six months ended June 30, 2013, the Company received notification from the American Maritime Officers Pension Plan (the "AMOPP”) that based on an actuarial valuation performed as of September 30, 2012, if the Company chooses to withdraw from the AMOPP, its withdrawal liability will be $45.6 million. That liability may change in future years based on various factors, primarily employee census. As of June 30, 2013, the Company has no intention to withdraw from the AMOPP and no deficit amounts have been invoiced. Depending upon the results of the future actuarial valuations and the ten-year rehabilitation plan, it is possible that the AMOPP will experience further funding deficits, requiring the Company to recognize additional payroll related operating expenses in the periods invoices are received or contribution levels are increased.
	During the six months ended June 30, 2013, the Company also received notification from the United Kingdom Merchant Navy Officers Pension Fund ("MNOPF") that the results of a 2012 actuarial valuation indicated that an additional net funding deficit of $182.6 million (£120.0 million) had developed since the previous actuarial valuation in 2009 and the Company's allocable share of the additional deficit is $2.7 million (£1.8 million). The Company will recognize additional payroll related operating expenses in the period the deficit invoice is received from the MNOPF, which is expected to be before the end of 2013. Depending upon the results of the future actuarial valuations, it is possible that the MNOPF will experience further funding deficits, requiring the Company to recognize additional payroll related operating expenses in the periods invoices are received.

LongTerm_Debt_and_Capital_Leas

Long-Term Debt and Capital Lease Obligations	6 Months Ended
	Jun. 30, 2013
Long-term Debt and Capital Lease Obligations [Abstract]	'
Long-Term Debt and Capital Lease Obligations	'
	LONG-TERM DEBT AND CAPITAL LEASE OBLIGATIONS
	As of June 30, 2013, the remaining availability under the SEACOR revolving credit facility was $359.0 million, net of issued letters of credit of $1.0 million. In addition, as of June 30, 2013, the Company had other outstanding letters of credit totaling $27.1 million with various expiration dates through 2016.
	During the six months ended June 30, 2013, the Company made scheduled payments on other long-term debt and capital lease obligations of $10.0 million and made net repayments of $2.4 million under inventory financing arrangements.
	SEACOR’s Board of Directors has previously authorized the Company to purchase any or all of its 7.375% Senior Notes due 2019, which may be acquired through open market purchases, privately negotiated transactions or otherwise, depending on market conditions. During the six months ended June 30, 2013, the Company did not repurchase any of its 7.375% Senior Notes due 2019.

Stock_Repurchases

Stock Repurchases	6 Months Ended
	Jun. 30, 2013
Stock Repurchases [Abstract]	'
Stock Repurchases [Text Block]	'
	STOCK REPURCHASES
	SEACOR’s Board of Directors previously approved a securities repurchase plan that authorizes the Company to acquire Common Stock, which may be acquired through open market purchases, privately negotiated transactions or otherwise, depending on market conditions. During the six months ended June 30, 2013, the Company did not acquire any shares of Common Stock for treasury. As of June 30, 2013, the remaining authority under the repurchase plan was $100.0 million.

Earnings_Per_Common_Share_of_S

Earnings Per Common Share of SEACOR	6 Months Ended
	Jun. 30, 2013
Earnings Per Common Share of SEACOR [Abstract]	'
Earnings Per Common Share of SEACOR	'
	EARNINGS PER COMMON SHARE OF SEACOR
	Basic earnings per common share of SEACOR are computed based on the weighted average number of common shares issued and outstanding during the relevant periods. Diluted earnings per common share of SEACOR are computed based on the weighted average number of common shares issued and outstanding plus the effect of potentially dilutive securities through the application of the treasury stock and if-converted methods. Dilutive securities for this purpose assumes restricted stock grants have vested, common shares have been issued pursuant to the exercise of outstanding stock options and common shares have been issued pursuant to the conversion of all outstanding convertible notes.
	Computations of basic and diluted earnings per common share of SEACOR were as follows (in thousands, except share data):
		For the Three Months Ended June 30,					For the Six Months Ended June 30,
		Net Income Attributable to SEACOR		Average O/S Shares	Per Share		Net Income Attributable to SEACOR			Average O/S Shares	Per Share
							(As Restated)				(As Restated)
	2013
	Basic Weighted Average Common Shares Outstanding	$	19,271	19,825,229	$	0.97	$	(1,717	)	19,782,318	$	(0.09	)
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—		366,558			—			332,586
	Convertible Notes(2)	3,044		4,200,525			—			—
	Diluted Weighted Average Common Shares Outstanding	$	22,315	24,392,312	$	0.91	$	(1,717	)	20,114,904	$	(0.09	)
		For the Three Months Ended June 30,					For the Six Months Ended June 30,
		Net Income Attributable to SEACOR		Average O/S Shares	Per Share		Net Income Attributable to SEACOR			Average O/S Shares	Per Share
	2012
	Basic Weighted Average Common Shares Outstanding	$	11,249	20,584,567	$	0.55	$	47,737		20,552,114	$	2.32
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—		286,813			—			331,456
	Diluted Weighted Average Common Shares Outstanding	$	11,249	20,871,380	$	0.54	$	47,737		20,883,570	$	2.29
	______________________
	-1	For the three months ended June 30, 2013 and 2012, diluted earnings per common share of SEACOR excluded 355,490 and 593,344 of certain share awards, respectively, as the effect of their inclusion in the computation would be anti-dilutive. For the six months ended June 30, 2013 and 2012, diluted earnings per share of SEACOR excluded 503,726 and 531,101 of certain share awards, respectively, as the effect of their inclusion in the computation would be anti-dilutive.
	-2	For the six months ended June 30, 2013, diluted earnings per common share of SEACOR excluded 4,200,525 common shares issuable pursuant to the Company's 2.5% Convertible Senior Notes as the effect of their inclusion in the computation would be anti-dilutive.

Share_Based_Compensation

Share Based Compensation	6 Months Ended
	Jun. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Share Based Compensation	'
	SHARE BASED COMPENSATION
	Transactions in connection with the Company’s share based compensation plans during the six months ended June 30, 2013 were as follows:
	Director stock awards granted	1,500
	Employee Stock Purchase Plan (“ESPP”) shares issued	18,056
	Restricted stock awards granted	147,800
	Restricted stock awards canceled	17,000
	Shares released from Deferred Compensation Plan	—
	Stock Option Activities:
	Outstanding as of December 31, 2012	1,281,821
	Granted(1)	431,662
	Exercised	(145,840	)
	Forfeited	—
	Expired	(1,576	)
	Outstanding as of June 30, 2013	1,566,067
	Shares available for future grants and ESPP purchases as of June 30, 2013	937,987
	______________________
	-1	During the six months ended June 30, 2013, the Company granted 318,012 stock options to existing option holders under make-whole provisions upon the Spin-off of Era Group.

Segment_Information

Segment Information	6 Months Ended
	Jun. 30, 2013
Segment Reporting [Abstract]	'
Segment Information	'
	SEGMENT INFORMATION
	Accounting standards require public business enterprises to report information about each of their operating business segments that exceed certain quantitative thresholds or meet certain other reporting requirements. Operating business segments have been defined as components of an enterprise about which separate financial information is available and is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. Certain reclassifications of prior period information have been made to conform to the current period's reportable segment presentation as a result of the Company's presentation of discontinued operations (see Notes 1 and 14). The Company’s basis of measurement of segment profit or loss is as previously described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.
	The following tables summarize the operating results, capital expenditures and assets of the Company's reportable segments.
		Offshore		Inland		Shipping		Ethanol and		Other		Corporate		Total
		Marine		River		Services		Industrial		$’000		and		$’000
		Services		Services		$’000		Alcohol				Eliminations
		$’000		$’000				$’000				$’000
	For the three months ended
	30-Jun-13
	Operating Revenues:
	External customers	138,650		46,780		48,103		61,378		20,652		—		315,563
	Intersegment	28		577		—		—		—		(605	)	—
		138,678		47,357		48,103		61,378		20,652		(605	)	315,563
	Costs and Expenses:
	Operating	97,581		35,193		29,554		59,402		18,960		(577	)	240,113
	Administrative and general	14,235		3,921		6,124		477		1,323		8,638		34,718
	Depreciation and amortization	16,460		7,078		7,907		1,489		96		753		33,783
		128,276		46,192		43,585		61,368		20,379		8,814		308,614
	Gains on Asset Dispositions, Net	7,895		4,296		114		—		—		—		12,305
	Operating Income (Loss)	18,297		5,461		4,632		10		273		(9,419	)	19,254
	Other Income (Expense):
	Derivative gains (losses), net	175		—		—		473		(450	)	(1,023	)	(825	)
	Foreign currency (gains) losses, net	(833	)	219		(8	)	—		(169	)	(125	)	(916	)
	Other, net	11		—		188		—		—		(4	)	195
	Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	7,694		1		(403	)	—		418		—		7,710
	Segment Profit	25,344		5,681		4,409		483		72
	Other Income (Expense) not included in Segment Profit													1,853
	Less Equity Earnings (Losses) included in Segment Profit													(7,710	)
	Income Before Taxes, Equity Earnings and Discontinued Operations													19,561
		Offshore		Inland		Shipping		Ethanol and		Other		Corporate		Total
		Marine		River		Services		Industrial		$’000		and		$’000
		Services		Services		$’000		Alcohol(1)(2)				Eliminations
		$’000		$’000				$’000				$’000
	For the six months ended
	30-Jun-13
	Operating Revenues:
	External customers	262,642		96,203		94,579		94,227		34,976		—		582,627
	Intersegment	52		1,231		—		—		—		(1,283	)	—
		262,694		97,434		94,579		94,227		34,976		(1,283	)	582,627
	Costs and Expenses:
	Operating	187,612		71,582		56,168		93,447		33,448		(1,231	)	441,026
	Administrative and general	29,062		7,945		11,301		1,138		2,979		17,938		70,363
	Depreciation and amortization	32,747		14,162		15,704		2,978		195		1,545		67,331
		249,421		93,689		83,173		97,563		36,622		18,252		578,720
	Gains (Losses) on Asset Dispositions	10,234		4,993		(2,955	)	—		1,907		141		14,320
	and Impairments, Net
	Operating Income (Loss)	23,507		8,738		8,451		(3,336	)	261		(19,394	)	18,227
	Other Income (Expense):
	Derivative gains (losses), net	325		—		—		512		392		(4,161	)	(2,932	)
	Foreign currency gains (losses), net	(4,097	)	82		(15	)	—		(336	)	(561	)	(4,927	)
	Other, net	11		—		202		—		54		(69	)	198
	Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	9,007		(2,386	)	(1,908	)	—		2,128		—		6,841
	Segment Profit (Loss)	28,753		6,434		6,730		(2,824	)	2,499
	Other Income (Expense) not included in Segment Profit (Loss)													(3,825	)
	Less Equity Earnings (Losses) included in Segment Profit (Loss)													(6,841	)
	Income Before Taxes, Equity Earnings and Discontinued Operations													6,741
	Capital Expenditures	49,764		9,238		27,048		217		357		1,307		87,931
	As of June 30, 2013
	Property and Equipment:
	Historical cost	1,151,751		466,553		517,409		44,006		3,989		29,221		2,212,929
	Accumulated depreciation	(439,211	)	(134,235	)	(214,372	)	(8,614	)	(531	)	(9,709	)	(806,672	)
		712,540		332,318		303,037		35,392		3,458		19,512		1,406,257
	Construction in progress	90,847		17,700		22,037		—		2,087		1,314		133,985
	803,387		350,018		325,074		35,392		5,545		20,826		1,540,242
Investments, at Equity, and Advances to 50% or Less Owned Companies	84,418		55,875		66,786		—		86,714		—		293,793
Inventories	5,885		2,260		1,427		12,164		1,219		—		22,955
Goodwill	13,367		2,759		1,852		—		—		—		17,978
Intangible Assets	4,584		8,416		1,134		50		410		—		14,594
Other current and long-term assets, excluding cash and near cash assets(3)	146,551		37,260		16,021		10,925		56,591		22,225		289,573
Segment Assets	1,058,192		456,588		412,294		58,531		150,479
Cash and near cash assets(3)													589,198
Total Assets													2,768,333
______________________
-1	Operating revenues includes $92.7 million of tangible product sales and operating expenses includes $91.9 million of costs of goods sold.
-2	Inventories includes raw materials of $2.8 million and work in process of $2.2 million.
-3	Cash and near cash assets includes cash, cash equivalents, restricted cash, marketable securities, construction reserve funds and Title XI reserve funds.
	Offshore		Inland		Shipping		Ethanol and		Other		Corporate		Total
	Marine		River		Services		Industrial		$’000		and		$’000
	Services		Services		$’000		Alcohol				Eliminations
	$’000		$’000				$’000				$’000
For the three months ended
June 30, 2012
Operating Revenues:
External customers	123,359		53,302		42,716		58,938		30,910		—		309,225
Intersegment	(83	)	—		108		—		(17	)	(8	)	—
	123,276		53,302		42,824		58,938		30,893		(8	)	309,225
Costs and Expenses:
Operating	94,084		37,463		28,214		57,201		27,566		17		244,545
Administrative and general	13,146		3,773		5,505		434		5,899		7,544		36,301
Depreciation and amortization	15,859		7,244		7,362		1,578		711		466		33,220
	123,089		48,480		41,081		59,213		34,176		8,027		314,066
Gains on Asset Dispositions	624		858		1,860		—		—		—		3,342
Operating Income (Loss)	811		5,680		3,603		(275	)	(3,283	)	(8,035	)	(1,499	)
Other Income (Expense):
Derivative gains (losses), net	—		—		—		(236	)	2,516		274		2,554
Foreign currency losses, net	(354	)	(71	)	(4	)	—		(84	)	(511	)	(1,024	)
Other, net	11		—		257		—		—		175		443
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,001		439		(774	)	—		(371	)	—		295
Segment Profit (Loss)	1,469		6,048		3,082		(511	)	(1,222	)
Other Income (Expense) not included in Segment Profit (Loss)													8,976
Less Equity Earnings (Losses) included in Segment Profit (Loss)													(295	)
Income Before Taxes, Equity Earnings and Discontinued Operations													9,450
	Offshore		Inland		Shipping		Ethanol and		Other		Corporate		Total
	Marine		River		Services		Industrial		$’000		and		$’000
	Services		Services		$’000		Alcohol(1)(2)				Eliminations
	$’000		$’000				$’000				$’000
For the six months ended
30-Jun-12
Operating Revenues:
External customers	244,310		106,792		88,449		98,557		68,966		—		607,074
Intersegment	52		—		108		—		35		(195	)	—
	244,362		106,792		88,557		98,557		69,001		(195	)	607,074
Costs and Expenses:
Operating	169,424		72,646		55,786		94,606		60,643		(141	)	452,964
Administrative and general	25,002		7,755		10,372		859		10,697		16,607		71,292
Depreciation and amortization	28,741		14,251		14,979		2,630		1,400		921		62,922
	223,167		94,652		81,137		98,095		72,740		17,387		587,178
Gains on Asset Dispositions	2,469		2,785		1,860		—		5		—		7,119
Operating Income (Loss)	23,664		14,925		9,280		462		(3,734	)	(17,582	)	27,015
Other Income (Expense):
Derivative gains (losses), net	—		—		—		(721	)	1,099		(782	)	(404	)
Foreign currency gains (losses), net	769		(93	)	9		—		15		(63	)	637
Other, net	11		—		287		—		—		61		359
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	2,830		689		(991	)	6,154		(726	)	—		7,956
Segment Profit (Loss)	27,274		15,521		8,585		5,895		(3,346	)
Other Income (Expense) not included in Segment Profit (Loss)													4,830
Less Equity Earnings (Losses) included in Segment Profit (Loss)													(7,956	)
Income Before Taxes, Equity Earnings and Discontinued Operations													32,437
Capital Expenditures	64,383		13,108		12,921		—		6,314		2,781		99,507
As of June 30, 2012
Property and Equipment:
Historical cost	1,075,935		481,045		518,258		43,693		22,704		26,471		2,168,106
Accumulated depreciation	(393,813	)	(116,509	)	(188,148	)	(2,595	)	(3,587	)	(10,078	)	(714,730	)
	682,122		364,536		330,110		41,098		19,117		16,393		1,453,376
Construction in progress	107,709		12,790		14,065		—		2,864		5,672		143,100
	789,831		377,326		344,175		41,098		21,981		22,065		1,596,476
Investments, at Equity, and Advances to 50% or Less Owned Companies	68,081		53,859		90,626		—		69,426		—		281,992
Inventories	5,738		2,038		1,288		12,822		5,362		—		27,248
Goodwill	13,367		4,345		1,852		—		37,138		—		56,702
Intangible Assets	5,029		8,377		1,677		135		5,898		—		21,116
Other current and long-term assets, excluding cash and near cash assets(3)	148,525		49,890		16,410		7,154		83,664		35,858		341,501
Segment Assets	1,030,571		495,835		456,028		61,209		223,469
Cash and near cash assets(3)													533,439
Discontinued operations													987,343
Total Assets													3,845,817
______________________
-1	Operating revenues includes $96.6 million of tangible product sales and operating expenses includes $92.7 million of costs of goods sold.
-2	Inventories includes raw materials of $2.8 million and work in process of $2.4 million.
-3	Cash and near cash assets includes cash, cash equivalents, restricted cash, marketable securities, construction reserve funds and Title XI reserve funds.

Discontinued_Operations_Notes

Discontinued Operations (Notes)	6 Months Ended
	Jun. 30, 2013
Discontinued Operations [Abstract]	'
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	'
	14	DISCONTINUED OPERATIONS
	Summarized selected operating results of the Company's discontinued operations were as follows (in thousands):
			Three Months Ended June 30,					Six Months Ended June 30,
			2013		2012			2013			2012
								(As Restated)
	SES Business
	Operating Revenues		$	—	$	—		$	—		$	22,387
	Costs and Expenses:
	Operating		—		—			—			18,234
	Administrative and general		—		567			—			4,587
	Depreciation and amortization		—		—			—			1,428
			—		567			—			24,249
	Losses on Asset Dispositions		—		—			—			(71		)
	Operating Loss		—		(567		)	—			(1,933		)
	Other Income (Expense), Net (including gain on sale of business)		—		5			(1,537		)	24,971
	Income Tax Expense (Benefit)		—		(197		)	(538		)	4,305
	Equity in Earnings of 50% or Less Owned Companies		—		—			—			302
	Net Income (Loss)		$	—	$	(365	)	$	(999	)	$	19,035
	SEI
	Operating Revenues		$	—	$	153,388		$	—		$	316,318
	Costs and Expenses:
	Operating		—		150,837			—			310,800
	Administrative and general		—		1,626			—			3,136
	Depreciation and amortization		—		1			—			(4		)
			—		152,464			—			313,932
	Operating Income		—		924			—			2,386
	Other Income (Expense), Net (including gain on sale of business)		—		1,136			(143		)	5
	Income Tax Expense (Benefit)		—		864			(50		)	1,103
	Net Income (Loss)		$	—	$	1,196		$	(93	)	$	1,288
	Era Group
	Operating Revenues		$	—	$	62,985		$	22,892		$	124,037
	Costs and Expenses:
	Operating		—		39,002			14,076			78,678
	Administrative and general		—		7,195			2,653			16,872
	Depreciation and amortization		—		10,464			3,875			20,094
			—		56,661			20,604			115,644
	Gains on Asset Dispositions and Impairments, Net		—		1,077			548			2,842
	Operating Income		—		7,401			2,836			11,235
	Other Income (Expense), Net		—		(2,323		)	(1,316		)	(3,136		)
	Income Tax Expense(1)		—		1,861			10,818			2,770
	Equity in Earnings (Losses) of 50% or Less Owned Companies		—		756			65			(5,663		)
	Net Income (Loss)		$	—	$	3,973		$	(9,233	)	$	(334	)
	Eliminations
	Operating Revenues		$	—	$	(31,176	)	$	—		$	(55,124	)
	Costs and Expenses:
	Operating		—		(31,174		)	—			(55,122		)
	Administrative and general		—		(2		)	—			(2		)
			—		(31,176		)	—			(55,124		)
	Operating Income		$	—	$	—		$	—		$	—
	______________________
	-1	In late February 2014, the Company made a determination to provide for income taxes of $10.1 million relating to the Spin-off of Era Group, effective January 31, 2013. As a result, the Company has restated its results from discontinued operations for the six months ended June 30, 2013 in the table included herein (see Note 15).

Restatement_Notes

Restatement (Notes)	6 Months Ended
	Jun. 30, 2013
Restatement [Abstract]	'
Accounting Changes and Error Corrections [Text Block]	'
	Restatement of Interim Financial Results. In late February 2014, in connection with the Company’s year-end accounting review and preparation of its year-end financial statements, an error was discovered in the accounting for taxes related to the Spin-off of Era Group. The restatement of the Company's unaudited condensed consolidated financial statements in this Amendment No. 1 to the Original Filing is solely related to this error in accounting for taxes, the principal effect of which is an increase in the net loss from discontinued operations for the six months ended June 30, 2013 of $10.1 million (see Note 15).
	15	RESTATEMENT
	The restatement of the Company's unaudited condensed consolidated financial statements in this Amendment No. 1 to the Original Filing is solely related to an error in the accounting for taxes related to the Spin-off of Era Group, the principal effect of which is an increase in the net loss from discontinued operations for the six months ended June 30, 2013 of $10.1 million. The following table sets forth the effect of the restatement on each impacted financial statement line item (in thousands, except share data):
			June 30, 2013			June 30, 2013
			(As Restated)			(As Previously Reported)
	Balance Sheet (unaudited):
	Other current liabilities		$	122,424		$	112,310
	Total current liabilities		220,728			210,614
	Total liabilities		1,431,897			1,421,783
	Retained earnings		1,056,583			1,066,697
	SEACOR Holdings Inc. stockholders' equity		1,311,558			1,321,672
	Total equity		1,336,436			1,346,550
			For the Six Months Ended
			June 30, 2013			June 30, 2013
			(As Restated)			(As Previously Reported)
	Statement of Income (Loss) (unaudited):
	Loss from Discontinued Operations, Net of Tax		$	(10,325	)	$	(211	)
	Net Income (Loss)		(2,065		)	8,049
	Net Income (Loss) attributable to SEACOR Holdings Inc.		(1,717		)	8,397
	Net Income (Loss) attributable to SEACOR Holdings Inc.:
	Continuing operations		$	8,508		$	8,508
	Discontinued operations		(10,225		)	(111		)
			$	(1,717	)	$	8,397
	Basic Income (Loss) Per Common Share of SEACOR Holdings Inc.:
	Continuing operations		$	0.43		$	0.43
	Discontinued operations		(0.52		)	(0.01		)
			$	(0.09	)	$	0.42
	Diluted Income (Loss) Per Common Share of SEACOR Holdings Inc.:
	Continuing operations		$	0.42		$	0.42
	Discontinued operations		(0.51		)	—
			$	(0.09	)	$	0.42
	Statement of Comprehensive Income (Loss) (unaudited):
	Net Income (Loss)		$	(2,065	)	$	8,049
	Comprehensive Income (Loss)		(4,719		)	5,395
	Comprehensive Income (Loss) attributable to SEACOR Holdings Inc.		(3,919		)	6,195

Basis_of_Presentation_and_Acco1

Basis of Presentation and Accounting Policy (Policy)	6 Months Ended
	Jun. 30, 2013
Nature Of Operations And Accounting Policies [Abstract]	'
Basis Of Consolidation	'
	The condensed consolidated financial information for the three and six months ended June 30, 2013 and 2012 has been prepared by the Company and has not been audited by its independent registered public accounting firm. The condensed consolidated financial statements include the accounts of SEACOR Holdings Inc. and its consolidated subsidiaries. In the opinion of management, all adjustments (consisting of normal recurring adjustments) have been made to fairly present the Company’s financial position as of June 30, 2013, its results of operations for the three and six months ended June 30, 2013 and 2012, its comprehensive income for the three and six months ended June 30, 2013 and 2012, its changes in equity for the six months ended June 30, 2013, and its cash flows for the six months ended June 30, 2013 and 2012. Results of operations for the interim periods presented are not necessarily indicative of operating results for the full year or any future periods.
	Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States have been condensed or omitted. These condensed consolidated financial statements should be read in conjunction with the financial statements and related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.
	Unless the context otherwise indicates, any reference in this Quarterly Report on Form 10-Q to the “Company” refers to SEACOR Holdings Inc. and its consolidated subsidiaries and any reference in this Quarterly Report on Form 10-Q to “SEACOR” refers to SEACOR Holdings Inc.
Discontinued Operations, Policy	'
	Discontinued Operations. On January 31, 2013, the Company completed the spin-off ("Spin-off") of Era Group Inc. (“Era Group”), the company that operated SEACOR's Aviation Services business segment, by means of a dividend to SEACOR's stockholders of all the issued and outstanding common stock of Era Group. Era Group filed a Registration Statement on Form 10 with the Securities and Exchange Commission, describing the Spin-off, that was declared effective on January 14, 2013. Era Group is now an independent company whose common stock is listed on the New York Stock Exchange under the symbol "ERA." Discontinued operations includes the historical financial position, results of operations and cash flows of Era Group as well as the operations previously reported as discontinued in the Company's Annual Report on Form 10-K for the year ended December 31, 2012 (see Note 14).
Revenue Recognition	'
	Revenue Recognition. The Company recognizes revenue when it is realized or realizable and earned. Revenue is realized or realizable and earned when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price to the buyer is fixed or determinable, and collectability is reasonably assured. Revenue that does not meet these criteria is deferred until the criteria are met. Deferred revenues, included in other current liabilities, for the six months ended June 30 were as follows (in thousands):
		2013				2012
	Balance at beginning of period	$	6,592			$	9,845
	Revenues deferred during the period	—				2,600
	Revenues recognized during the period	—				(5,927		)
	Balance at end of period	$	6,592			$	6,518
	As of June 30, 2013, deferred revenues of $6.6 million were related to the time charter of several offshore support vessels scheduled to be paid through the conveyance of an overriding royalty interest (the "Conveyance") in developmental oil and gas producing properties operated by a customer in the U.S. Gulf of Mexico. Payments under the Conveyance, and the timing of such payments, are contingent upon production and energy sale prices. On August 17, 2012, the customer filed a voluntary petition for Chapter 11 bankruptcy. The Company is vigorously defending its interest in connection with the bankruptcy filing; however, payments received under the Conveyance subsequent to August 17, 2012 are subject to bankruptcy court approval. The Company will continue to recognize revenues as cash is received and approved by the bankruptcy court or earlier should future collection become reasonably assured. All costs and expenses related to these charters were recognized as incurred.
Reclassifications [Text Block]	'
	Reclassifications. Certain reclassifications of prior period information have been made to conform to the presentation of the current period information. These reclassifications had no effect on net income as previously reported.
Accounting Changes and Error Corrections [Text Block]	'
	Restatement of Interim Financial Results. In late February 2014, in connection with the Company’s year-end accounting review and preparation of its year-end financial statements, an error was discovered in the accounting for taxes related to the Spin-off of Era Group. The restatement of the Company's unaudited condensed consolidated financial statements in this Amendment No. 1 to the Original Filing is solely related to this error in accounting for taxes, the principal effect of which is an increase in the net loss from discontinued operations for the six months ended June 30, 2013 of $10.1 million (see Note 15).
	15	RESTATEMENT
	The restatement of the Company's unaudited condensed consolidated financial statements in this Amendment No. 1 to the Original Filing is solely related to an error in the accounting for taxes related to the Spin-off of Era Group, the principal effect of which is an increase in the net loss from discontinued operations for the six months ended June 30, 2013 of $10.1 million. The following table sets forth the effect of the restatement on each impacted financial statement line item (in thousands, except share data):
			June 30, 2013				June 30, 2013
			(As Restated)				(As Previously Reported)
	Balance Sheet (unaudited):
	Other current liabilities		$	122,424			$	112,310
	Total current liabilities		220,728				210,614
	Total liabilities		1,431,897				1,421,783
	Retained earnings		1,056,583				1,066,697
	SEACOR Holdings Inc. stockholders' equity		1,311,558				1,321,672
	Total equity		1,336,436				1,346,550
			For the Six Months Ended
			June 30, 2013				June 30, 2013
			(As Restated)				(As Previously Reported)
	Statement of Income (Loss) (unaudited):
	Loss from Discontinued Operations, Net of Tax		$	(10,325	)		$	(211	)
	Net Income (Loss)		(2,065		)		8,049
	Net Income (Loss) attributable to SEACOR Holdings Inc.		(1,717		)		8,397
	Net Income (Loss) attributable to SEACOR Holdings Inc.:
	Continuing operations		$	8,508			$	8,508
	Discontinued operations		(10,225		)		(111		)
			$	(1,717	)		$	8,397
	Basic Income (Loss) Per Common Share of SEACOR Holdings Inc.:
	Continuing operations		$	0.43			$	0.43
	Discontinued operations		(0.52		)		(0.01		)
			$	(0.09	)		$	0.42
	Diluted Income (Loss) Per Common Share of SEACOR Holdings Inc.:
	Continuing operations		$	0.42			$	0.42
	Discontinued operations		(0.51		)		—
			$	(0.09	)		$	0.42
	Statement of Comprehensive Income (Loss) (unaudited):
	Net Income (Loss)		$	(2,065	)		$	8,049
	Comprehensive Income (Loss)		(4,719		)		5,395
	Comprehensive Income (Loss) attributable to SEACOR Holdings Inc.		(3,919		)		6,195

Basis_of_Presentation_and_Acco2

Basis of Presentation and Accounting Policy (Tables)	6 Months Ended
	Jun. 30, 2013
Nature Of Operations And Accounting Policies [Abstract]	'
Deferred Revenues Included In Other Current Liabilities	'
	Deferred revenues, included in other current liabilities, for the six months ended June 30 were as follows (in thousands):
		2013				2012
	Balance at beginning of period	$	6,592			$	9,845
	Revenues deferred during the period	—				2,600
	Revenues recognized during the period	—				(5,927		)
	Balance at end of period	$	6,592			$	6,518
Comprehensive Income (Loss) Note [Text Block]	'
	Accumulated Other Comprehensive Loss. The components of accumulated other comprehensive income (loss) were as follows:
			SEACOR Holdings Inc. Stockholders Equity													Noncontrolling
																Interests
			Foreign				Derivative			Other			Total			Foreign			Other			Other
			Currency				Losses on									Currency						Comprehensive
			Translation				Cash Flow									Translation						Income (Loss)
			Adjustments				Hedges, net									Adjustments
	31-Dec-12		$	(1,238	)		$	(732	)	$	(16	)	$	(1,986	)	$	321		$	(10	)
	Distribution of Era Group stock to shareholders		(55		)		—			—			(55		)	—			—
	Other comprehensive income (loss)		(4,086		)		698			—			(3,388		)	(452		)	—			$	(3,840	)
	Income tax (expense) benefit		1,430				(244		)	—			1,186			—			—			1,186
	Six months ended June 30, 2013		$	(3,949	)		$	(278	)	$	(16	)	$	(4,243	)	$	(131	)	$	(10	)	$	(2,654	)

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2013
Fair Value Disclosures [Abstract]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	'
	The Company’s financial assets and liabilities as of June 30, 2013 that are measured at fair value on a recurring basis were as follows (in thousands):
		Level 1			Level 2			Level 3
	ASSETS
	Marketable securities(1)	$	27,264		$	—		$	—
	Derivative instruments (included in other receivables)	820			5,961			—
	Construction reserve funds and Title XI reserve funds	150,375			—			—
	LIABILITIES
	Short sale of marketable securities (included in other current liabilities)	7,809			—			—
	Derivative instruments (included in other current liabilities)	703			4,770			—
	______________________
	-1	Marketable security gains, net include unrealized gains of $6.5 million and unrealized losses of $2.0 million for the three months ended June 30, 2013 and 2012, respectively, related to marketable security positions held by the Company as of June 30, 2013.
Estimated Fair Value Of Other Financial Assets And Liabilities	'
	The estimated fair values of the Company’s other financial assets and liabilities as of June 30, 2013 were as follows (in thousands):
					Estimated Fair Value
		Carrying			Level 1			Level 2			Level 3
		Amount
	ASSETS
	Cash, cash equivalents and restricted cash	$	411,559		$	411,559		$	—		$	—
	Investments, at cost, in 50% or less owned companies (included in other	9,315			see below
	assets)
	Notes receivable from other business ventures (included in other	21,674			see below
	receivables and other assets)
	LIABILITIES
	Long-term debt, including current portion(1)	699,553			—			813,568			—
	______________________
	-1	The estimated fair value includes the conversion option on the Company's 2.5% Convertible Notes.
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Table Text Block]	'
	The Company’s non-financial assets and liabilities that were measured at fair value during the six months ended June 30, 2013 were as follows (in thousands):
			Level 1			Level 2			Level 3
	ASSETS
	Long-lived assets under construction(1)		$	17,494		$	—		$	—
	Investment in C-Lift LLC(2)		—			13,290			—
	______________________
	-1	During the six months ended June 30, 2013, the Company recognized impairment charges of $3.0 million related to two of Shipping Services' harbor tugs while under construction, which were sold and leased back upon their completion (see Note 5).
	-2	During the six months ended June 30, 2013, the Company marked its equity investment in C-Lift LLC ("C-Lift") to fair value following its acquisition of a controlling interest (see Note 4). The investment's fair value was determined based on the Company's purchase price of the acquired interest.

Derivative_Instruments_And_Hed1

Derivative Instruments And Hedging Strategies (Tables)	6 Months Ended
	Jun. 30, 2013
Derivative [Line Items]	'
Fair Values Of Derivative Instruments	'
	The fair values of the Company’s derivative instruments as of June 30, 2013 were as follows (in thousands):
		Derivative			Derivative
		Asset			Liability
	Options on equities and equity indices	$	415		$	—
	Forward currency exchange, option and future contracts	298			390
	Interest rate swap agreements	—			4,271
	Commodity swap, option and future contracts:
	Exchange traded	554			703
	Non-exchange traded	5,514			109
		$	6,781		$	5,473
Cash Flow Hedging [Member]	'
Derivative [Line Items]	'
Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments	'
	The Company recognized gains (losses) on derivative instruments designated as cash flow hedges for the six months ended June 30 as follows (in thousands):
		2013			2012
	Interest rate swap agreements, effective portion in other comprehensive income (loss)	$	380		$	(671	)
	Interest rate swap agreements, ineffective portion in derivative gains (losses), net	—			(19		)
		$	380		$	(690	)
Not Designated as Hedging Instrument [Member]	'
Derivative [Line Items]	'
Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments	'
	The Company recognized gains (losses) on derivative instruments not designated as hedging instruments in derivative gains (losses), net for the six months ended June 30 as follows (in thousands):
		2013			2012
	Options on equities and equity indices	$	(3,012	)	$	(910	)
	Forward currency exchange, option and future contracts	(592		)	373
	Interest rate swap agreements	237			(237		)
	Commodity swap, option and future contracts:
	Exchange traded	(821		)	(1,863		)
	Non-exchange traded	1,256			2,252
		$	(2,932	)	$	(385	)

Business_Acquisitions_Tables

Business Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2013
Business Combinations [Abstract]	'
Allocation Of Purchase Price For Business Acquisitions	'
	The following table summarizes the allocation of the purchase price for the Company’s business acquisitions during the six months ended June 30, 2013 (in thousands):
	Trade and other receivables	$	3,250
	Other current assets	32
	Investments, at Equity, and Advances to 50% or Less Owned Companies	(13,290		)
	Property and Equipment	43,521
	Intangible Assets	1,599
	Accounts payable	(264		)
	Other current liabilities	(1,640		)
	Long-Term Debt	(22,668		)
	Purchase price(1)	$	10,540

Equipment_Acquisitions_Disposi1

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies (Tables)	6 Months Ended
	Jun. 30, 2013
Equipment Acquisitions, Dispositions And Depreciation And Impairment Policies [Abstract]	'
Schedule Of Deferred Gain Activity [Table Text Block]	'
	Deferred gain activity related to these transactions for the six months ended June 30 was as follows (in thousands):
		2013			2012
	Balance at beginning of period	$	111,514		$	117,192
	Deferred gains arising from asset sales	2,289			7,280
	Amortization of deferred gains included in operating expenses as a reduction to rental expense	(5,192		)	(9,526		)
	Amortization of deferred gains included in gains on asset dispositions and impairments, net	(1,431		)	(2,039		)
	Balance at end of period	$	107,180		$	112,907
Schedule of Estimated Useful Life of Newly Acquired Equipment [Table Text Block]	'
	As of June 30, 2013, the estimated useful life (in years) of each of the Company’s major categories of new equipment was as follows:
	Offshore support vessels (excluding wind farm utility)	20
	Wind farm utility vessels	10
	Inland river dry cargo and deck barges	20
	Inland river liquid tank barges	25
	Inland river towboats	25
	U.S.-flag product tankers	25
	RORO(1) vessels	20
	Harbor tugs	25
	Ocean liquid tank barges	25
	Terminal and manufacturing facilities	20
	______________________
	-1	Roll on/Roll off ("RORO").

Earnings_Per_Common_Share_of_S1

Earnings Per Common Share of SEACOR (Tables)	6 Months Ended
	Jun. 30, 2013
Earnings Per Common Share of SEACOR [Abstract]	'
Schedule of Weighted Average Number of Shares [Table Text Block]	'
	Computations of basic and diluted earnings per common share of SEACOR were as follows (in thousands, except share data):
		For the Three Months Ended June 30,					For the Six Months Ended June 30,
		Net Income Attributable to SEACOR		Average O/S Shares	Per Share		Net Income Attributable to SEACOR			Average O/S Shares	Per Share
							(As Restated)				(As Restated)
	2013
	Basic Weighted Average Common Shares Outstanding	$	19,271	19,825,229	$	0.97	$	(1,717	)	19,782,318	$	(0.09	)
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—		366,558			—			332,586
	Convertible Notes(2)	3,044		4,200,525			—			—
	Diluted Weighted Average Common Shares Outstanding	$	22,315	24,392,312	$	0.91	$	(1,717	)	20,114,904	$	(0.09	)
		For the Three Months Ended June 30,					For the Six Months Ended June 30,
		Net Income Attributable to SEACOR		Average O/S Shares	Per Share		Net Income Attributable to SEACOR			Average O/S Shares	Per Share
	2012
	Basic Weighted Average Common Shares Outstanding	$	11,249	20,584,567	$	0.55	$	47,737		20,552,114	$	2.32
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—		286,813			—			331,456
	Diluted Weighted Average Common Shares Outstanding	$	11,249	20,871,380	$	0.54	$	47,737		20,883,570	$	2.29
	______________________
	-1	For the three months ended June 30, 2013 and 2012, diluted earnings per common share of SEACOR excluded 355,490 and 593,344 of certain share awards, respectively, as the effect of their inclusion in the computation would be anti-dilutive. For the six months ended June 30, 2013 and 2012, diluted earnings per share of SEACOR excluded 503,726 and 531,101 of certain share awards, respectively, as the effect of their inclusion in the computation would be anti-dilutive.
	-2	For the six months ended June 30, 2013, diluted earnings per common share of SEACOR excluded 4,200,525 common shares issuable pursuant to the Company's 2.5% Convertible Senior Notes as the effect of their inclusion in the computation would be anti-dilutive.

Share_Based_Compensation_Table

Share Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Share Based Compensation Plans	'
	Transactions in connection with the Company’s share based compensation plans during the six months ended June 30, 2013 were as follows:
	Director stock awards granted	1,500
	Employee Stock Purchase Plan (“ESPP”) shares issued	18,056
	Restricted stock awards granted	147,800
	Restricted stock awards canceled	17,000
	Shares released from Deferred Compensation Plan	—
	Stock Option Activities:
	Outstanding as of December 31, 2012	1,281,821
	Granted(1)	431,662
	Exercised	(145,840	)
	Forfeited	—
	Expired	(1,576	)
	Outstanding as of June 30, 2013	1,566,067
	Shares available for future grants and ESPP purchases as of June 30, 2013	937,987
	______________________
	-1	During the six months ended June 30, 2013, the Company granted 318,012 stock options to existing option holders under make-whole provisions upon the Spin-off of Era Group.

Segment_Information_Tables

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2013
Segment Reporting [Abstract]	'
Operating Results, Capital Expenditures And Assets By Reporting Segment	'
	unting standards require public business enterprises to report information about each of their operating business segments that exceed certain quantitative thresholds or meet certain other reporting requirements. Operating business segments have been defined as components of an enterprise about which separate financial information is available and is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. Certain reclassifications of prior period information have been made to conform to the current period's reportable segment presentation as a result of the Company's presentation of discontinued operations (see Notes 1 and 14). The Company’s basis of measurement of segment profit or loss is as previously described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.
	The following tables summarize the operating results, capital expenditures and assets of the Company's reportable segments.
		Offshore		Inland		Shipping		Ethanol and		Other		Corporate		Total
		Marine		River		Services		Industrial		$’000		and		$’000
		Services		Services		$’000		Alcohol				Eliminations
		$’000		$’000				$’000				$’000
	For the three months ended
	30-Jun-13
	Operating Revenues:
	External customers	138,650		46,780		48,103		61,378		20,652		—		315,563
	Intersegment	28		577		—		—		—		(605	)	—
		138,678		47,357		48,103		61,378		20,652		(605	)	315,563
	Costs and Expenses:
	Operating	97,581		35,193		29,554		59,402		18,960		(577	)	240,113
	Administrative and general	14,235		3,921		6,124		477		1,323		8,638		34,718
	Depreciation and amortization	16,460		7,078		7,907		1,489		96		753		33,783
		128,276		46,192		43,585		61,368		20,379		8,814		308,614
	Gains on Asset Dispositions, Net	7,895		4,296		114		—		—		—		12,305
	Operating Income (Loss)	18,297		5,461		4,632		10		273		(9,419	)	19,254
	Other Income (Expense):
	Derivative gains (losses), net	175		—		—		473		(450	)	(1,023	)	(825	)
	Foreign currency (gains) losses, net	(833	)	219		(8	)	—		(169	)	(125	)	(916	)
	Other, net	11		—		188		—		—		(4	)	195
	Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	7,694		1		(403	)	—		418		—		7,710
	Segment Profit	25,344		5,681		4,409		483		72
	Other Income (Expense) not included in Segment Profit													1,853
	Less Equity Earnings (Losses) included in Segment Profit													(7,710	)
	Income Before Taxes, Equity Earnings and Discontinued Operations													19,561
		Offshore		Inland		Shipping		Ethanol and		Other		Corporate		Total
		Marine		River		Services		Industrial		$’000		and		$’000
		Services		Services		$’000		Alcohol(1)(2)				Eliminations
		$’000		$’000				$’000				$’000
	For the six months ended
	30-Jun-13
	Operating Revenues:
	External customers	262,642		96,203		94,579		94,227		34,976		—		582,627
	Intersegment	52		1,231		—		—		—		(1,283	)	—
		262,694		97,434		94,579		94,227		34,976		(1,283	)	582,627
	Costs and Expenses:
	Operating	187,612		71,582		56,168		93,447		33,448		(1,231	)	441,026
	Administrative and general	29,062		7,945		11,301		1,138		2,979		17,938		70,363
	Depreciation and amortization	32,747		14,162		15,704		2,978		195		1,545		67,331
		249,421		93,689		83,173		97,563		36,622		18,252		578,720
	Gains (Losses) on Asset Dispositions	10,234		4,993		(2,955	)	—		1,907		141		14,320
	and Impairments, Net
	Operating Income (Loss)	23,507		8,738		8,451		(3,336	)	261		(19,394	)	18,227
	Other Income (Expense):
	Derivative gains (losses), net	325		—		—		512		392		(4,161	)	(2,932	)
	Foreign currency gains (losses), net	(4,097	)	82		(15	)	—		(336	)	(561	)	(4,927	)
	Other, net	11		—		202		—		54		(69	)	198
	Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	9,007		(2,386	)	(1,908	)	—		2,128		—		6,841
	Segment Profit (Loss)	28,753		6,434		6,730		(2,824	)	2,499
	Other Income (Expense) not included in Segment Profit (Loss)													(3,825	)
	Less Equity Earnings (Losses) included in Segment Profit (Loss)													(6,841	)
	Income Before Taxes, Equity Earnings and Discontinued Operations													6,741
	Capital Expenditures	49,764		9,238		27,048		217		357		1,307		87,931
	As of June 30, 2013
	Property and Equipment:
	Historical cost	1,151,751		466,553		517,409		44,006		3,989		29,221		2,212,929
	Accumulated depreciation	(439,211	)	(134,235	)	(214,372	)	(8,614	)	(531	)	(9,709	)	(806,672	)
		712,540		332,318		303,037		35,392		3,458		19,512		1,406,257
	Construction in progress	90,847		17,700		22,037		—		2,087		1,314		133,985
		803,387		350,018		325,074		35,392		5,545		20,826		1,540,242
Investments, at Equity, and Advances to 50% or Less Owned Companies	84,418		55,875		66,786		—		86,714		—		293,793
Inventories	5,885		2,260		1,427		12,164		1,219		—		22,955
Goodwill	13,367		2,759		1,852		—		—		—		17,978
Intangible Assets	4,584		8,416		1,134		50		410		—		14,594
Other current and long-term assets, excluding cash and near cash assets(3)	146,551		37,260		16,021		10,925		56,591		22,225		289,573
Segment Assets	1,058,192		456,588		412,294		58,531		150,479
Cash and near cash assets(3)													589,198
Total Assets													2,768,333
______________________
-1	Operating revenues includes $92.7 million of tangible product sales and operating expenses includes $91.9 million of costs of goods sold.
-2	Inventories includes raw materials of $2.8 million and work in process of $2.2 million.
-3	Cash and near cash assets includes cash, cash equivalents, restricted cash, marketable securities, construction reserve funds and Title XI reserve funds.
	Offshore		Inland		Shipping		Ethanol and		Other		Corporate		Total
	Marine		River		Services		Industrial		$’000		and		$’000
	Services		Services		$’000		Alcohol				Eliminations
	$’000		$’000				$’000				$’000
For the three months ended
June 30, 2012
Operating Revenues:
External customers	123,359		53,302		42,716		58,938		30,910		—		309,225
Intersegment	(83	)	—		108		—		(17	)	(8	)	—
	123,276		53,302		42,824		58,938		30,893		(8	)	309,225
Costs and Expenses:
Operating	94,084		37,463		28,214		57,201		27,566		17		244,545
Administrative and general	13,146		3,773		5,505		434		5,899		7,544		36,301
Depreciation and amortization	15,859		7,244		7,362		1,578		711		466		33,220
	123,089		48,480		41,081		59,213		34,176		8,027		314,066
Gains on Asset Dispositions	624		858		1,860		—		—		—		3,342
Operating Income (Loss)	811		5,680		3,603		(275	)	(3,283	)	(8,035	)	(1,499	)
Other Income (Expense):
Derivative gains (losses), net	—		—		—		(236	)	2,516		274		2,554
Foreign currency losses, net	(354	)	(71	)	(4	)	—		(84	)	(511	)	(1,024	)
Other, net	11		—		257		—		—		175		443
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,001		439		(774	)	—		(371	)	—		295
Segment Profit (Loss)	1,469		6,048		3,082		(511	)	(1,222	)
Other Income (Expense) not included in Segment Profit (Loss)													8,976
Less Equity Earnings (Losses) included in Segment Profit (Loss)													(295	)
Income Before Taxes, Equity Earnings and Discontinued Operations													9,450
	Offshore		Inland		Shipping		Ethanol and		Other		Corporate		Total
	Marine		River		Services		Industrial		$’000		and		$’000
	Services		Services		$’000		Alcohol(1)(2)				Eliminations
	$’000		$’000				$’000				$’000
For the six months ended
30-Jun-12
Operating Revenues:
External customers	244,310		106,792		88,449		98,557		68,966		—		607,074
Intersegment	52		—		108		—		35		(195	)	—
	244,362		106,792		88,557		98,557		69,001		(195	)	607,074
Costs and Expenses:
Operating	169,424		72,646		55,786		94,606		60,643		(141	)	452,964
Administrative and general	25,002		7,755		10,372		859		10,697		16,607		71,292
Depreciation and amortization	28,741		14,251		14,979		2,630		1,400		921		62,922
	223,167		94,652		81,137		98,095		72,740		17,387		587,178
Gains on Asset Dispositions	2,469		2,785		1,860		—		5		—		7,119
Operating Income (Loss)	23,664		14,925		9,280		462		(3,734	)	(17,582	)	27,015
Other Income (Expense):
Derivative gains (losses), net	—		—		—		(721	)	1,099		(782	)	(404	)
Foreign currency gains (losses), net	769		(93	)	9		—		15		(63	)	637
Other, net	11		—		287		—		—		61		359
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	2,830		689		(991	)	6,154		(726	)	—		7,956
Segment Profit (Loss)	27,274		15,521		8,585		5,895		(3,346	)
Other Income (Expense) not included in Segment Profit (Loss)													4,830
Less Equity Earnings (Losses) included in Segment Profit (Loss)													(7,956	)
Income Before Taxes, Equity Earnings and Discontinued Operations													32,437
Capital Expenditures	64,383		13,108		12,921		—		6,314		2,781		99,507
As of June 30, 2012
Property and Equipment:
Historical cost	1,075,935		481,045		518,258		43,693		22,704		26,471		2,168,106
Accumulated depreciation	(393,813	)	(116,509	)	(188,148	)	(2,595	)	(3,587	)	(10,078	)	(714,730	)
	682,122		364,536		330,110		41,098		19,117		16,393		1,453,376
Construction in progress	107,709		12,790		14,065		—		2,864		5,672		143,100
	789,831		377,326		344,175		41,098		21,981		22,065		1,596,476
Investments, at Equity, and Advances to 50% or Less Owned Companies	68,081		53,859		90,626		—		69,426		—		281,992
Inventories	5,738		2,038		1,288		12,822		5,362		—		27,248
Goodwill	13,367		4,345		1,852		—		37,138		—		56,702
Intangible Assets	5,029		8,377		1,677		135		5,898		—		21,116
Other current and long-term assets, excluding cash and near cash assets(3)	148,525		49,890		16,410		7,154		83,664		35,858		341,501
Segment Assets	1,030,571		495,835		456,028		61,209		223,469
Cash and near cash assets(3)													533,439
Discontinued operations													987,343
Total Assets													3,845,817
______________________
-1	Operating revenues includes $96.6 million of tangible product sales and operating expenses includes $92.7 million of costs of goods sold.
-2	Inventories includes raw materials of $2.8 million and work in process of $2.4 million.
-3	Cash and near cash assets includes cash, cash equivalents, restricted cash, marketable securities, construction reserve funds and Title XI reserve funds.

Discontinued_Operations_Tables

Discontinued Operations (Tables)	6 Months Ended
	Jun. 30, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]	'
	Summarized selected operating results of the Company's discontinued operations were as follows (in thousands):
			Three Months Ended June 30,					Six Months Ended June 30,
			2013		2012			2013			2012
								(As Restated)
	SES Business
	Operating Revenues		$	—	$	—		$	—		$	22,387
	Costs and Expenses:
	Operating		—		—			—			18,234
	Administrative and general		—		567			—			4,587
	Depreciation and amortization		—		—			—			1,428
			—		567			—			24,249
	Losses on Asset Dispositions		—		—			—			(71		)
	Operating Loss		—		(567		)	—			(1,933		)
	Other Income (Expense), Net (including gain on sale of business)		—		5			(1,537		)	24,971
	Income Tax Expense (Benefit)		—		(197		)	(538		)	4,305
	Equity in Earnings of 50% or Less Owned Companies		—		—			—			302
	Net Income (Loss)		$	—	$	(365	)	$	(999	)	$	19,035
	SEI
	Operating Revenues		$	—	$	153,388		$	—		$	316,318
	Costs and Expenses:
	Operating		—		150,837			—			310,800
	Administrative and general		—		1,626			—			3,136
	Depreciation and amortization		—		1			—			(4		)
			—		152,464			—			313,932
	Operating Income		—		924			—			2,386
	Other Income (Expense), Net (including gain on sale of business)		—		1,136			(143		)	5
	Income Tax Expense (Benefit)		—		864			(50		)	1,103
	Net Income (Loss)		$	—	$	1,196		$	(93	)	$	1,288
	Era Group
	Operating Revenues		$	—	$	62,985		$	22,892		$	124,037
	Costs and Expenses:
	Operating		—		39,002			14,076			78,678
	Administrative and general		—		7,195			2,653			16,872
	Depreciation and amortization		—		10,464			3,875			20,094
			—		56,661			20,604			115,644
	Gains on Asset Dispositions and Impairments, Net		—		1,077			548			2,842
	Operating Income		—		7,401			2,836			11,235
	Other Income (Expense), Net		—		(2,323		)	(1,316		)	(3,136		)
	Income Tax Expense(1)		—		1,861			10,818			2,770
	Equity in Earnings (Losses) of 50% or Less Owned Companies		—		756			65			(5,663		)
	Net Income (Loss)		$	—	$	3,973		$	(9,233	)	$	(334	)
	Eliminations
	Operating Revenues		$	—	$	(31,176	)	$	—		$	(55,124	)
	Costs and Expenses:
	Operating		—		(31,174		)	—			(55,122		)
	Administrative and general		—		(2		)	—			(2		)
			—		(31,176		)	—			(55,124		)
	Operating Income		$	—	$	—		$	—		$	—
	______________________
	-1	In late February 2014, the Company made a determination to provide for income taxes of $10.1 million relating to the Spin-off of Era Group, effective January 31, 2013. As a result, the Company has restated its results from discontinued operations for the six months ended June 30, 2013 in the table included herein (see Note 15).

Restatement_Tables

Restatement (Tables)	6 Months Ended
	Jun. 30, 2013
Restatement [Abstract]	'
Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]	'
	The following table sets forth the effect of the restatement on each impacted financial statement line item (in thousands, except share data):
		June 30, 2013			June 30, 2013
		(As Restated)			(As Previously Reported)
	Balance Sheet (unaudited):
	Other current liabilities	$	122,424		$	112,310
	Total current liabilities	220,728			210,614
	Total liabilities	1,431,897			1,421,783
	Retained earnings	1,056,583			1,066,697
	SEACOR Holdings Inc. stockholders' equity	1,311,558			1,321,672
	Total equity	1,336,436			1,346,550
		For the Six Months Ended
		June 30, 2013			June 30, 2013
		(As Restated)			(As Previously Reported)
	Statement of Income (Loss) (unaudited):
	Loss from Discontinued Operations, Net of Tax	$	(10,325	)	$	(211	)
	Net Income (Loss)	(2,065		)	8,049
	Net Income (Loss) attributable to SEACOR Holdings Inc.	(1,717		)	8,397
	Net Income (Loss) attributable to SEACOR Holdings Inc.:
	Continuing operations	$	8,508		$	8,508
	Discontinued operations	(10,225		)	(111		)
		$	(1,717	)	$	8,397
	Basic Income (Loss) Per Common Share of SEACOR Holdings Inc.:
	Continuing operations	$	0.43		$	0.43
	Discontinued operations	(0.52		)	(0.01		)
		$	(0.09	)	$	0.42
	Diluted Income (Loss) Per Common Share of SEACOR Holdings Inc.:
	Continuing operations	$	0.42		$	0.42
	Discontinued operations	(0.51		)	—
		$	(0.09	)	$	0.42
	Statement of Comprehensive Income (Loss) (unaudited):
	Net Income (Loss)	$	(2,065	)	$	8,049
	Comprehensive Income (Loss)	(4,719		)	5,395
	Comprehensive Income (Loss) attributable to SEACOR Holdings Inc.	(3,919		)	6,195

Basis_of_Presentation_and_Acco3

Basis of Presentation and Accounting Policy (Narrative) (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2013	Dec. 31, 2013	Jun. 30, 2013
					Offshore Marine Services [Member]	Era Group [Member]	Era Group [Member]
Nature of Operations and Accounting Policies [Line Items]	'	'	'	'	'	'	'
Liability for Uncertain Tax Positions, Current	'	'	'	'	'	$10,100,000	$10,100,000
Deferred Revenue	$6,592,000	$6,592,000	$6,518,000	$9,845,000	$6,600,000	'	'

Basis_of_Presentation_and_Acco4

Basis of Presentation and Accounting Policy (Deferred Revenues Included In Other Current Liabilities) (Details) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012
Nature Of Operations And Accounting Policies [Abstract]	'	'
Balance at beginning of period	$6,592	$9,845
Revenues deferred during the period	0	2,600
Revenues recognized during the period	0	-5,927
Balance at end of period	$6,592	$6,518

Basis_of_Presentation_and_Acco5

Basis of Presentation and Accounting Policy Accumulated Other Comprehensive Income (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax	($4,243)	'	($4,243)	'	($1,986)
Stockholders' Equity Note, Spinoff Transaction	'	'	-415,371	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	'	'	-3,388	'	'
Other Comprehensive Income (Loss), before Tax	142	-805	-3,840	3,429	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	'	'	1,186	'	'
Other Comprehensive Income (Loss), Tax	-41	249	1,186	-1,145	'
Other Comprehensive Income (Loss), Net of Tax	101	-556	-2,654	2,284	'
Accumulated Translation Adjustment [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	-3,949	'	-3,949	'	-1,238
Stockholders' Equity Note, Spinoff Transaction	'	'	-55	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	'	'	-4,086	'	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	'	'	1,430	'	'
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	-278	'	-278	'	-732
Stockholders' Equity Note, Spinoff Transaction	'	'	0	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	'	'	698	'	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	'	'	-244	'	'
Other Postretirement Benefit Plans, Defined Benefit [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	-16	'	-16	'	-16
Stockholders' Equity Note, Spinoff Transaction	'	'	0	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	'	'	0	'	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	'	'	0	'	'
Non-Controlling Interests In Subsidiaries [Member]	'	'	'	'	'
Stockholders' Equity Note, Spinoff Transaction	'	'	-107	'	'
Other Comprehensive Income (Loss), Net of Tax	'	'	-452	'	'
Non-Controlling Interests In Subsidiaries [Member] | Accumulated Translation Adjustment [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	-131	'	-131	'	321
Stockholders' Equity Note, Spinoff Transaction	'	'	0	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Noncontrolling Interest	'	'	-452	'	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest	'	'	0	'	'
Non-Controlling Interests In Subsidiaries [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	-10	'	-10	'	-10
Stockholders' Equity Note, Spinoff Transaction	'	'	0	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Noncontrolling Interest	'	'	0	'	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest	'	'	0	'	'
Accumulated Other Comprehensive Income (Loss) [Member]	'	'	'	'	'
Stockholders' Equity Note, Spinoff Transaction	'	'	-55	'	'
Other Comprehensive Income (Loss), Net of Tax	'	'	($2,202)	'	'

Fair_Value_Measurements_Financ

Fair Value Measurements (Financial Assets And Liabilities Measured At Fair Value On Recurring Basis) (Details) (USD $)	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Jun. 30, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'
Construction Reserve Funds & Title XI Reserve Funds	'	'	$150,375,000	$195,629,000
Marketable security gains (losses), net include losses	6,500,000	-2,000,000	10,500,000	'
Fair Value, Inputs, Level 1 [Member]	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'
Marketable securities	'	'	27,264,000	'
Derivative instruments (included in other receivables)	'	'	820,000	'
Construction Reserve Funds & Title XI Reserve Funds	'	'	150,375,000	'
Short sales of marketable securities	'	'	7,809,000	'
Derivative instruments (included in other current liabilities)	'	'	703,000	'
Fair Value, Inputs, Level 2 [Member]	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'
Marketable securities	'	'	0	'
Derivative instruments (included in other receivables)	'	'	5,961,000	'
Construction reserve funds and Title XI reserve funds	'	'	0	'
Short sales of marketable securities	'	'	0	'
Derivative instruments (included in other current liabilities)	'	'	4,770,000	'
Fair Value, Inputs, Level 3 [Member]	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'
Marketable securities	'	'	0	'
Derivative instruments (included in other receivables)	'	'	0	'
Construction reserve funds and Title XI reserve funds	'	'	0	'
Short sales of marketable securities	'	'	0	'
Derivative instruments (included in other current liabilities)	'	'	$0	'

Fair_Value_Measurements_Estima

Fair Value Measurements (Estimated Fair Value Of Other Financial Assets And Liabilities) (Details) (USD $)	Jun. 30, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Cash, cash equivalents and restricted cash, Carrying Amount	$411,559
Investments, at cost, in 50% or less owned companies (included in other assets), Carrying Amount	9,315
Notes receivable from other business ventures (included in other receivables and other assets)	21,674
Long-term debt, including current portion, Carrying Amount	699,553
Fair Value, Inputs, Level 1 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Cash and Cash Equivalents, Fair Value Disclosure	411,559
Debt Instrument, Fair Value Disclosure	0
Fair Value, Inputs, Level 2 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Cash and Cash Equivalents, Fair Value Disclosure	0
Debt Instrument, Fair Value Disclosure	813,568
Fair Value, Inputs, Level 3 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Cash and Cash Equivalents, Fair Value Disclosure	0
Debt Instrument, Fair Value Disclosure	$0
Two Point Five Percentage Convertible Notes [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	2.50%

Fair_Value_Measurements_NonFin

Fair Value Measurements (Non-Financial Assets And Liabilities Measured At Fair Value) (Details) (USD $)	Jun. 30, 2013
In Thousands, unless otherwise specified
Fair Value, Inputs, Level 1 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Assets Held-for-sale, Long Lived	$17,494
Fair Value, Inputs, Level 2 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Assets Held-for-sale, Long Lived	0
Fair Value, Inputs, Level 3 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Assets Held-for-sale, Long Lived	0
C Lift L L C [Member] | Fair Value, Inputs, Level 1 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Equity Method Investments, Fair Value Disclosure	0
C Lift L L C [Member] | Fair Value, Inputs, Level 2 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Equity Method Investments, Fair Value Disclosure	13,290
C Lift L L C [Member] | Fair Value, Inputs, Level 3 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Equity Method Investments, Fair Value Disclosure	$0

Derivative_Instruments_And_Hed2

Derivative Instruments And Hedging Strategies (Narrative) (Details)

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

In Millions, unless otherwise specified

Not Designated as Hedging Instrument [Member]

SEACOR Holdings Inc. [Member]

Offshore Marine Services Joint Ventures [Member]

Offshore Marine Services Joint Ventures [Member]

Inland River Joint Venture [Member]

Inland River Joint Venture [Member]

Shipping Services [Member]

Shipping Services [Member]

Dynamic Offshore Drilling Ltd [Member]

Not Designated as Hedging Instrument [Member]

Not Designated as Hedging Instrument [Member]

Not Designated as Hedging Instrument [Member]

Not Designated as Hedging Instrument [Member]

USD ($)

Not Designated as Hedging Instrument [Member]

USD ($)

Cash Flow Hedging [Member]

USD ($)

Cash Flow Hedging [Member]

USD ($)

Cash Flow Hedging [Member]

Interest Rate Swap Agreements [Member]

Windcat Acquisition [Member]

Windcat Acquisition [Member]

Dynamic Offshore Drilling Ltd [Member]

USD ($)

Interest Rate Swap Agreements [Member]

Interest Rate Swap Agreements [Member]

Interest Rate Swap Agreements [Member]

USD ($)

EUR (€)

USD ($)

Derivative [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Fixed interest rate range, minimum

'

2.25%

'

'

'

1.53%

'

'

'

'

'

'

'

Fixed interest rate range, maximum

'

3.05%

'

'

'

4.16%

'

'

'

'

'

'

'

Derivative, Notional Amount

$13.10

'

$17.50

'

$38.80

'

$38.40

'

'

$221.10

$14.40

€ 10.90

$108

Fixed interest rate

'

'

'

1.48%

'

'

'

2.79%

1.30%

'

'

'

'

Derivative_Instruments_And_Hed3

Derivative Instruments And Hedging Strategies (Fair Values Of Derivative Instruments) (Details) (Not Designated as Hedging Instrument [Member], USD $)	Jun. 30, 2013
In Thousands, unless otherwise specified
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	$6,781
Derivative Liability	5,473
Foreign Exchange [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	298
Derivative Liability	390
Interest Rate Swap Agreements [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	0
Derivative Liability	4,271
Options On Equities And Equity Indices [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	415
Derivative Liability	0
Commodity Swap, Option And Future Contracts, Non-Exchange Traded [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	5,514
Derivative Liability	109
Commodity Contract [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	554
Derivative Liability	$703

Derivative_Instruments_And_Hed4

Derivative Instruments And Hedging Strategies (Recognized Gains (Losses) On Derivative Instruments Designated As Cash Flow Hedges) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	$331,000	($195,000)	'	'
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax	'	'	0	-19,000
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	'	'	380,000	-690,000
Interest Rate Swap Agreements [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	'	'	380,000	-671,000
Offshore Marine Services Joint Ventures [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative, Notional Amount	17,500,000	'	17,500,000	'
Offshore Marine Services Joint Ventures [Member] | Cash Flow Hedging [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative, Fixed Interest Rate	1.48%	'	1.48%	'
Inland River Joint Venture [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative, Notional Amount	$38,800,000	'	$38,800,000	'
Inland River Joint Venture [Member] | Cash Flow Hedging [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative, Lower Fixed Interest Rate Range	1.53%	'	1.53%	'
Derivative, Higher Fixed Interest Rate Range	4.16%	'	4.16%	'

Derivative_Instruments_And_Hed5

Derivative Instruments And Hedging Strategies (Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments) (Details) (USD $)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Derivative [Line Items]	'	'
Derivative gains (losses), net	($2,932,000)	($385,000)
Options On Equities And Equity Indices [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	-3,012,000	-910,000
Forward Currency Exchange, Option And Future Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	-592,000	373,000
Interest Rate Swap Agreements [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	237,000	-237,000
Commodity Contract [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	-821,000	-1,863,000
Commodity Swap, Option And Future Contracts, Non-Exchange Traded [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	1,256,000	2,252,000
Not Designated as Hedging Instrument [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Notional Amount	13,100,000	'
SEACOR Holdings Inc. [Member] | Not Designated as Hedging Instrument [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Lower Fixed Interest Rate Range	2.25%	'
Derivative, Higher Fixed Interest Rate Range	3.05%	'
Offshore Marine Services Joint Ventures [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Notional Amount	17,500,000	'
Not Designated as Hedging Instrument [Member] | Interest Rate Swap Agreements [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Notional Amount	$221,100,000	'

Business_Acquisitions_Narrativ

Business Acquisitions (Narrative) (Details) (USD $)	6 Months Ended				12 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2013	Jun. 06, 2013	Jun. 06, 2013	Dec. 31, 2012	Jun. 25, 2012	Dec. 31, 2012	Mar. 30, 2012
		C Lift L L C [Member]	C Lift L L C [Member]	C Lift L L C [Member]	Pantagro Acquisition [Member] [Member]	Pantagro Acquisition [Member] [Member]	Superior Energy Services, LLC [Member]	Superior Energy Services, LLC [Member]
				Liftboats [Member]				Liftboats [Member]
Business Acquisition [Line Items]	'	'	'	'	'	'	'	'
Business Acquisition, Percentage of Voting Interests Acquired	'	'	50.00%	'	'	'	'	'
Cash Acquired from Acquisition	$2.20	'	'	'	'	'	'	'
Payments to Acquire Businesses, Gross	'	12.7	'	'	0.2	'	142.5	'
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred	'	'	'	'	0.2	'	'	'
Equity Method Investment, Ownership Percentage	'	'	100.00%	'	'	95.00%	'	'
Business Combination, Consideration Transferred	'	'	'	'	$0.40	'	'	'
Number Of Equipments Acquired	'	'	'	2	'	'	'	18

Business_Acquisitions_Allocati

Business Acquisitions (Allocation Of Purchase Price For Business Acquisitions) (Details) (USD $)	Jun. 30, 2013
In Thousands, unless otherwise specified
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]	'
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	$3,250
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other	32
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Investmnets, at Equity, and Advnaces to 50% or Less Owned Companies	-13,290
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant and Equipment	43,521
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangible Assets	1,599
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable	264
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other	1,640
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt	22,668
Purchase price	$10,540	[1]
[1]	Trade and other receivables$3,250Other current assets32Investments, at Equity, and Advances to 50% or Less Owned Companies(13,290)Property and Equipment43,521Intangible Assets1,599Accounts payable(264)Other current liabilities(1,640)Long-Term Debt(22,668)Purchase price(1)$10,540______________________(1)Purchase price is net of cash acquired of $2.2 million.

Equipment_Acquisitions_Disposi2

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies (Deferred Gain Activity) (Details) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012
Movement in Deferred Gain Activity [Roll Forward]	'	'
Deferred Gains at Beginning of Period	$111,514	$117,192
Deferred Gain On Sale Of Equipments	2,289	7,280
Amortization Of Deferred Gains Included in Operating Expenses As A Reduction To Rental Expense	-5,192	-9,526
Amortization Of Deferred Gains Included In Gains On Asset Dispositions And Impairments, Net	-1,431	-2,039
Deferred Gains at End of Period	$107,180	$112,907

Equipment_Acquisitions_Disposi3

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies (Useful Life) (Details)	6 Months Ended
	Jun. 30, 2013
Offshore Support Vessels [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'20 years
Wind Farm Utility Vessel [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'10 years
Inland River Dry Cargo And Deck Barges [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'20 years
Inland River Liquid Tank Barges [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'25 years
Inland River Towboats [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'25 years
U S Flag Tankers [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'25 years
R O R O Vessels [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'20 years	[1]
Harbor And Offshore Tugs [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'25 years
Ocean Liquid Tank Barge [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'25 years
Terminal And Manufacturing Facilities [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'20 years
[1]	Roll on/Roll off ("RORO").

Equipment_Acquisitions_Disposi4

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies (Narrative) (Details) (USD $)

3 Months Ended

6 Months Ended

12 Months Ended

6 Months Ended

12 Months Ended

6 Months Ended

12 Months Ended

6 Months Ended

12 Months Ended

6 Months Ended

12 Months Ended

Mar. 31, 2013

Jun. 30, 2013

Jun. 30, 2012

Jun. 30, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2012

Jun. 30, 2013

Jun. 30, 2013

Dec. 31, 2012

Jun. 30, 2013

Dec. 31, 2012

Jun. 30, 2013

Dec. 31, 2012

Jun. 30, 2013

Jun. 30, 2013

Dec. 31, 2012

Offshore Support Vessels Specialty [Member]

Offshore Support Vessels Specialty [Member]

Offshore Support Vessels Crew [Member]

Offshore Support Vessels Mini Supply [Member]

Offshore Support Vessels Supply [Member]

Liftboats [Member]

Wind Farm Utility Vessel [Member]

Inland River Dry Cargo And Deck Barges [Member]

Inland River Liquid Tank Barges [Member]

Inland River Liquid Tank Barges [Member]

U.S.-flag Harbor Tugs [Member]

U.S.-flag Harbor Tugs [Member]

Mexmar [Member]

Gains on Asset Dispositions and Impariments, Net [Member]

Gains on Asset Dispositions and Impariments, Net [Member]

equipment

equipment

equipment

equipment

equipment

equipment

equipment

equipment

equipment

equipment

equipment

Property, Plant and Equipment [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchases of property and equipment

'

$87,931,000

$99,507,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number Of Equipments Delivered

'

'

'

1

'

'

'

'

2

2

'

2

'

'

3

'

'

'

Number Of Equipments Sold

'

'

'

'

1

2

1

1

3

'

16

'

8

'

2

'

'

'

Sales Price Of Equipment

'

132,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from Sale of Property, Plant and Equipment, Excluding Deposits on Future Equipment Sales

'

125,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Vendor Credits

'

200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from disposition of property and equipment

'

125,432,000

7,394,000

'

'

'

'

'

'

'

'

'

'

'

'

60,500,000

'

'

Proceeds from Issuance of Secured Debt

'

7,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gains (Losses) on Sales of Assets

15,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

12,900,000

Deferred Gains on Asset Sales

'

2,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization Of Deferred Gains Included In Gains On Asset Dispositions And Impairments, Net

'

-1,431,000

-2,039,000

'

'

'

'

'

'

'

'

'

'

'

'

'

1,400,000

'

Proceeds from Other Deposits

'

300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Asset Impairment Charges

'

'

'

'

'

'

'

'

'

'

'

'

'

$3,000,000

'

'

'

'

Investments_At_Equity_And_Adva1

Investments, At Equity, And Advances To 50% Or Less Owned Companies (Narrative) (Details) (USD $)

6 Months Ended

3 Months Ended

6 Months Ended

6 Months Ended

6 Months Ended

Jun. 30, 2013

Jun. 30, 2012

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 06, 2013

Sea-Cat Crewzer II [Member]

Mexmar [Member]

SCFCo Holdings [Member]

Bunge Scf Grain [Member]

Witt O'Brien's LLC [Member]

Corporate Joint Venture [Member]

Offshore Marine Services Joint Ventures [Member]

Offshore Support Vessels [Member]

Offshore Support Vessels [Member]

Offshore Support Vessels [Member]

Very Large Gas Carrier [Member]

Subsequent Event [Member]

C Lift L L C [Member]

C Lift L L C [Member]

equipment

Sea-Cat Crewzer II [Member]

Mexmar [Member]

equipment

Dorian LPG [Member]

equipment

equipment

Schedule Of Equity Method Investments [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Equity Method Investment, Ownership Percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

Equity Method Investment, Ownership Percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

50.00%

Payments to Acquire Businesses, Gross

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$12,700,000

'

Business Acquisition, Preexisting Relationship, Gain (Loss) Recognized

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,200,000

Partners' Capital Account, Contributions, Cash

'

'

11,500,000

5,900,000

2,900,000

'

'

500,000

'

'

'

'

'

42,100,000

'

'

Partners' Capital Account, Contributions, Noncash

'

'

'

'

'

'

'

'

'

'

'

'

'

14,900,000

'

'

Number Of Equipments Delivered

'

'

'

'

'

'

'

'

'

'

1

1

'

'

'

'

Proceeds From Property And Equipment Sales To Fifty Percent Or Less Owned Companies

'

'

24,100,000

36,400,000

'

'

'

'

'

'

'

'

'

'

'

'

Payments to Acquire Machinery and Equipment

'

'

23,000,000

30,400,000

'

'

'

'

'

'

'

'

'

'

'

'

Secured Debt

'

'

1,100,000

6,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Secured Debt, Repayments

'

'

'

6,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Loans/notes receivable

'

'

'

1,700,000

'

'

'

'

'

'

'

'

'

'

'

'

Temporary Working Capital Advances Provided during the Period

'

'

'

'

1,800,000

2,500,000

'

'

'

'

'

'

'

'

'

'

Temporary Working Capital Advances Repaid during the Period

'

'

'

'

1,800,000

500,000

'

'

'

'

'

'

'

'

'

'

Outstanding Working Capital Advances At End Of Period

'

'

'

'

2,300,000

7,000,000

'

'

'

'

'

'

'

'

'

'

Proceeds from Equity Method Investment, Dividends or Distributions

8,315,000

25,641,000

'

'

'

'

1,200,000

'

400,000

'

'

'

'

'

'

'

Unrecorded Unconditional Purchase Obligation, Maximum Quantity

'

'

'

'

'

'

'

'

'

17

'

'

2

'

'

'

Guarantor Obligations, Maximum Exposure, Undiscounted

14,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Allocable Share of Uncalled Capital

$2,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Commitments_And_Contingencies_

Commitments And Contingencies (Narrative) (Details) (USD $)

Jun. 30, 2013

Jun. 08, 2011

Dec. 31, 2010

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2012

Dec. 31, 2012

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Mar. 31, 2012

Robins Case [Member]

Wunstell Action [Member]

Darnell Alexander [Member]

Prejean [Member]

Abney Litigation [Member]

HEPACO Litigation [Member]

Offshore Support Vessels [Member]

Inland River Liquid Tank Barges [Member]

Inland River Towboats [Member]

Harbor Tugs [Member]

U.S.-flag Harbor Tugs [Member]

Very Large Gas Carrier [Member]

Other Machinery and Equipment [Member]

Dorian LPG [Member]

Aviation Services [Member]

claim

plaintiff

claim

claim

claim

equipment

equipment

equipment

equipment

equipment

Subsequent Event [Member]

Loss Contingencies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total unfunded capital commitments

$150,100,000

'

'

'

'

'

'

$128,200,000

$2,900,000

$10,900,000

'

$1,600,000

'

$6,500,000

'

'

Unrecorded Unconditional Purchase Obligation, Maximum Quantity

'

'

'

'

'

'

'

17

2

5

1

'

2

'

'

'

Partners' Capital Account, Contributions, Cash

'

'

'

'

'

'

'

'

'

'

'

'

'

'

42,100,000

'

Partners' Capital Account, Contributions, Noncash

'

'

'

'

'

'

'

'

'

'

'

'

'

'

14,900,000

'

Purchase commitments payable during the period

55,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrecorded Unconditional Purchase Obligation Balance Sheet Amount Potential Amount To Reduce Liability

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

139,400,000

Number of claims company did not attempt to dismiss

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Additional individual civil actions filed

'

'

2

117

3

668

'

'

'

'

'

'

'

'

'

'

Loss Contingency, Damages Sought, Value

'

'

'

'

'

'

$20,291,178.92

'

'

'

'

'

'

'

'

'

Multiemployer_Pension_Plans_De

Multiemployer Pension Plans (Details)	Sep. 30, 2012	Jun. 30, 2013	Jun. 30, 2013
In Millions, unless otherwise specified	American Maritime Officers Pension Plan [Member]	United Kingdom Merchant Navy Officers Pension Fund [Member]	United Kingdom Merchant Navy Officers Pension Fund [Member]
	USD ($)	USD ($)	GBP (£)
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement benefit plans, withdrawal liability	$45.60	'	'
Pension And Other Postretirement Benefit Plans, Total Funding Deficit	'	182.6	120
Pension and Other Postretirement Benefit Plans, Allocated Share of Funding Deficit	'	$2.70	£ 1.8

LongTerm_Debt_and_Capital_Leas1

Long-Term Debt and Capital Lease Obligations (Details) (USD $)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Debt Instrument [Line Items]	'	'
Letters of Credit Outstanding, Amount	$27,100,000	'
Repayments of Debt and Capital Lease Obligations	10,027,000	64,712,000
Net borrowings (repayments) on inventory financing arrangements	-2,365,000	14,798,000
Seacor Revolving Credit Facility [Member]	'	'
Debt Instrument [Line Items]	'	'
Line of Credit Facility, Remaining Borrowing Capacity	359,000,000	'
Letters of Credit Outstanding, Amount	$1,000,000	'
Seven Point Three Seven Five Percentage Senior Notes Due Two Thousand Nineteen Member	'	'
Debt Instrument [Line Items]	'	'
Debt Instrument, Interest Rate, Stated Percentage	7.38%	'

Stock_Repurchases_Details

Stock Repurchases (Details) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013
Stock Repurchases [Abstract]	'
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$100

Earnings_Per_Common_Share_of_S2

Earnings Per Common Share of SEACOR (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]	'	'	'	'
Net Income (Loss) Attributable to Parent	$19,271	$11,249	($1,717)	$47,737
Net Income (Loss) Available to Common Stockholders, Diluted	22,315	11,249	-1,717	47,737
Weighted Average Number of Shares Outstanding, Basic	19,825,229	20,584,567	19,782,318	20,552,114
Incremental Common Shares Attributable to Share-based Payment Arrangements	366,558	286,813	332,586	331,456
Incremental Common Shares Attributable to Conversion of Debt Securities	4,200,525	'	0	'
Weighted Average Number of Shares Outstanding, Diluted	24,392,312	20,871,380	20,114,904	20,883,570
Earnings Per Share, Basic	$0.97	$0.55	($0.09)	$2.32
Earnings Per Share, Diluted	$0.91	$0.54	($0.09)	$2.29
Outstanding Stock Awards [Member]	'	'	'	'
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	355,490	593,344	503,726	531,101
Two Point Five Percentage Convertible Notes [Domain]	'	'	'	'
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	'	'	4,200,525	'
Equity Securities [Member]	'	'	'	'
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]	'	'	'	'
Dilutive Securities, Effect on Basic Earnings Per Share	0	0	0	0
Convertible Debt Securities [Member]	'	'	'	'
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]	'	'	'	'
Dilutive Securities, Effect on Basic Earnings Per Share	$3,044	'	$0	'
Two Point Five Percentage Convertible Notes [Member]	'	'	'	'
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	2.50%	'	2.50%	'

Share_Based_Compensation_Share

Share Based Compensation (Share Based Compensation Plans) (Details)	6 Months Ended
	Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Director stock awards granted	1,500,000
Employee Stock Purchase Plan shares issued	18,056,000
Restricted stock awards granted	147,800,000
Restricted stock awards forfeited	17,000,000
Shares released from Deferred Compensation Plan	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'
Stock Options, Outstanding as of December 31, 2012	1,281,821,000
Stock Option, Granted	431,662,000
Stock Option, Exercised	-145,840,000
Stock Option, Forfeited	0
Stock Option, Expired	-1,576,000
Stock Options, Outstanding as of June 30, 2013	1,566,067,000
Shares available for future grants and ESPP purchases as of June 30, 2013	937,987,000
Era Group [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'
Stock Option, Granted	318,012

Segment_Information_Operating_

Segment Information (Operating Results, Capital Expenditures And Assets By Reportable Segments) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	$315,563,000	$309,225,000	$582,627,000	$607,074,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Administrative and general	34,718,000	36,301,000	70,363,000	71,292,000	'
Depreciation and amortization	33,783,000	33,220,000	67,331,000	62,922,000	'
Total costs and expenses	308,614,000	314,066,000	578,720,000	587,178,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	12,305,000	3,342,000	14,320,000	7,119,000	'
Operating Income (Loss)	19,254,000	-1,499,000	18,227,000	27,015,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	-825,000	2,554,000	-2,932,000	-404,000	'
Foreign currency gains (losses), net	-916,000	-1,024,000	-4,927,000	637,000	'
Other Nonoperating Income (Expense)	195,000	443,000	198,000	359,000	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	7,710,000	295,000	6,841,000	7,956,000	'
Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	19,561,000	9,450,000	6,741,000	32,437,000	'
Capital Expenditures	'	'	87,931,000	99,507,000	'
Property, Plant and Equipment, Gross	2,212,929,000	'	2,212,929,000	'	2,238,383,000
Accumulated depreciation	806,672,000	'	806,672,000	'	763,803,000
Property, Plant and Equipment, Net In Service	1,406,257,000	'	1,406,257,000	'	1,474,580,000
Construction in Progress, Gross	133,985,000	'	133,985,000	'	110,296,000
Net property and equipment	1,540,242,000	'	1,540,242,000	'	1,584,876,000
Inventories	22,955,000	'	22,955,000	'	25,787,000
Goodwill	17,978,000	'	17,978,000	'	17,978,000
Intangible Assets, Net	14,594,000	'	14,594,000	'	15,305,000
Total assets	2,768,333,000	3,845,817,000	2,768,333,000	3,845,817,000	3,700,794,000
Offshore Marine Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	138,650,000	123,359,000	262,642,000	244,310,000	'
Inland River Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	46,780,000	53,302,000	96,203,000	106,792,000	'
Shipping Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	48,103,000	42,716,000	94,579,000	88,449,000	'
Ethanol and Industrial Alcohol [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	61,378,000	58,938,000	94,227,000	98,557,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Sales Revenue, Goods, Net	'	'	92,700,000	96,600,000	'
Cost of Goods Sold	'	'	91,900,000	92,700,000	'
Inventory, Raw Materials	2,800,000	2,800,000	2,800,000	2,800,000	'
Inventory, Work in Process	2,200,000	2,400,000	2,200,000	2,400,000	'
Other Segments [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	20,652,000	30,910,000	34,976,000	68,966,000	'
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	315,563,000	309,225,000	582,627,000	607,074,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Operating Expenses	240,113,000	244,545,000	441,026,000	452,964,000	'
Administrative and general	34,718,000	36,301,000	70,363,000	71,292,000	'
Depreciation and amortization	33,783,000	33,220,000	67,331,000	62,922,000	'
Total costs and expenses	308,614,000	314,066,000	578,720,000	587,178,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	12,305,000	3,342,000	14,320,000	7,119,000	'
Operating Income (Loss)	19,254,000	-1,499,000	18,227,000	27,015,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	-825,000	2,554,000	-2,932,000	-404,000	'
Foreign currency gains (losses), net	-916,000	-1,024,000	-4,927,000	637,000	'
Other Nonoperating Income (Expense)	195,000	443,000	198,000	359,000	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	7,710,000	295,000	6,841,000	7,956,000	'
Capital Expenditures	'	'	87,931,000	99,507,000	'
Property, Plant and Equipment, Gross	2,212,929,000	2,168,106,000	2,212,929,000	2,168,106,000	'
Accumulated depreciation	806,672,000	714,730,000	806,672,000	714,730,000	'
Property, Plant and Equipment, Net In Service	1,406,257,000	1,453,376,000	1,406,257,000	1,453,376,000	'
Construction in Progress, Gross	133,985,000	143,100,000	133,985,000	143,100,000	'
Net property and equipment	1,540,242,000	1,596,476,000	1,540,242,000	1,596,476,000	'
Investments, at Equity, and Advances to 50% or Less Owned Companies	293,793,000	281,992,000	293,793,000	281,992,000	'
Inventories	22,955,000	27,248,000	22,955,000	27,248,000	'
Goodwill	17,978,000	56,702,000	17,978,000	56,702,000	'
Intangible Assets, Net	14,594,000	21,116,000	14,594,000	21,116,000	'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	289,573,000	341,501,000	289,573,000	341,501,000	'
Operating Segments [Member] | Offshore Marine Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	138,678,000	123,276,000	262,694,000	244,362,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Operating Expenses	97,581,000	94,084,000	187,612,000	169,424,000	'
Administrative and general	14,235,000	13,146,000	29,062,000	25,002,000	'
Depreciation and amortization	16,460,000	15,859,000	32,747,000	28,741,000	'
Total costs and expenses	128,276,000	123,089,000	249,421,000	223,167,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	7,895,000	624,000	10,234,000	2,469,000	'
Operating Income (Loss)	18,297,000	811,000	23,507,000	23,664,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	175,000	0	325,000	0	'
Foreign currency gains (losses), net	-833,000	-354,000	-4,097,000	769,000	'
Other Nonoperating Income (Expense)	11,000	11,000	11,000	11,000	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	7,694,000	1,001,000	9,007,000	2,830,000	'
Segment Profit (Loss)	25,344,000	1,469,000	28,753,000	27,274,000	'
Capital Expenditures	'	'	49,764,000	64,383,000	'
Property, Plant and Equipment, Gross	1,151,751,000	1,075,935,000	1,151,751,000	1,075,935,000	'
Accumulated depreciation	439,211,000	393,813,000	439,211,000	393,813,000	'
Property, Plant and Equipment, Net In Service	712,540,000	682,122,000	712,540,000	682,122,000	'
Construction in Progress, Gross	90,847,000	107,709,000	90,847,000	107,709,000	'
Net property and equipment	803,387,000	789,831,000	803,387,000	789,831,000	'
Investments, at Equity, and Advances to 50% or Less Owned Companies	84,418,000	68,081,000	84,418,000	68,081,000	'
Inventories	5,885,000	5,738,000	5,885,000	5,738,000	'
Goodwill	13,367,000	13,367,000	13,367,000	13,367,000	'
Intangible Assets, Net	4,584,000	5,029,000	4,584,000	5,029,000	'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	146,551,000	148,525,000	146,551,000	148,525,000	'
Total assets	1,058,192,000	1,030,571,000	1,058,192,000	1,030,571,000	'
Operating Segments [Member] | Inland River Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	47,357,000	53,302,000	97,434,000	106,792,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Operating Expenses	35,193,000	37,463,000	71,582,000	72,646,000	'
Administrative and general	3,921,000	3,773,000	7,945,000	7,755,000	'
Depreciation and amortization	7,078,000	7,244,000	14,162,000	14,251,000	'
Total costs and expenses	46,192,000	48,480,000	93,689,000	94,652,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	4,296,000	858,000	4,993,000	2,785,000	'
Operating Income (Loss)	5,461,000	5,680,000	8,738,000	14,925,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	0	0	0	0	'
Foreign currency gains (losses), net	219,000	-71,000	82,000	-93,000	'
Other Nonoperating Income (Expense)	0	0	0	0	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,000	439,000	-2,386,000	689,000	'
Segment Profit (Loss)	5,681,000	6,048,000	6,434,000	15,521,000	'
Capital Expenditures	'	'	9,238,000	13,108,000	'
Property, Plant and Equipment, Gross	466,553,000	481,045,000	466,553,000	481,045,000	'
Accumulated depreciation	134,235,000	116,509,000	134,235,000	116,509,000	'
Property, Plant and Equipment, Net In Service	332,318,000	364,536,000	332,318,000	364,536,000	'
Construction in Progress, Gross	17,700,000	12,790,000	17,700,000	12,790,000	'
Net property and equipment	350,018,000	377,326,000	350,018,000	377,326,000	'
Investments, at Equity, and Advances to 50% or Less Owned Companies	55,875,000	53,859,000	55,875,000	53,859,000	'
Inventories	2,260,000	2,038,000	2,260,000	2,038,000	'
Goodwill	2,759,000	4,345,000	2,759,000	4,345,000	'
Intangible Assets, Net	8,416,000	8,377,000	8,416,000	8,377,000	'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	37,260,000	49,890,000	37,260,000	49,890,000	'
Total assets	456,588,000	495,835,000	456,588,000	495,835,000	'
Operating Segments [Member] | Shipping Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	48,103,000	42,824,000	94,579,000	88,557,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Operating Expenses	29,554,000	28,214,000	56,168,000	55,786,000	'
Administrative and general	6,124,000	5,505,000	11,301,000	10,372,000	'
Depreciation and amortization	7,907,000	7,362,000	15,704,000	14,979,000	'
Total costs and expenses	43,585,000	41,081,000	83,173,000	81,137,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	114,000	1,860,000	-2,955,000	1,860,000	'
Operating Income (Loss)	4,632,000	3,603,000	8,451,000	9,280,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	0	0	0	0	'
Foreign currency gains (losses), net	-8,000	-4,000	-15,000	9,000	'
Other Nonoperating Income (Expense)	188,000	257,000	202,000	287,000	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	-403,000	-774,000	-1,908,000	-991,000	'
Segment Profit (Loss)	4,409,000	3,082,000	6,730,000	8,585,000	'
Capital Expenditures	'	'	27,048,000	12,921,000	'
Property, Plant and Equipment, Gross	517,409,000	518,258,000	517,409,000	518,258,000	'
Accumulated depreciation	214,372,000	188,148,000	214,372,000	188,148,000	'
Property, Plant and Equipment, Net In Service	303,037,000	330,110,000	303,037,000	330,110,000	'
Construction in Progress, Gross	22,037,000	14,065,000	22,037,000	14,065,000	'
Net property and equipment	325,074,000	344,175,000	325,074,000	344,175,000	'
Investments, at Equity, and Advances to 50% or Less Owned Companies	66,786,000	90,626,000	66,786,000	90,626,000	'
Inventories	1,427,000	1,288,000	1,427,000	1,288,000	'
Goodwill	1,852,000	1,852,000	1,852,000	1,852,000	'
Intangible Assets, Net	1,134,000	1,677,000	1,134,000	1,677,000	'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	16,021,000	16,410,000	16,021,000	16,410,000	'
Total assets	412,294,000	456,028,000	412,294,000	456,028,000	'
Operating Segments [Member] | Ethanol and Industrial Alcohol [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	61,378,000	58,938,000	94,227,000	98,557,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Operating Expenses	59,402,000	57,201,000	93,447,000	94,606,000	'
Administrative and general	477,000	434,000	1,138,000	859,000	'
Depreciation and amortization	1,489,000	1,578,000	2,978,000	2,630,000	'
Total costs and expenses	61,368,000	59,213,000	97,563,000	98,095,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	0	0	0	'
Operating Income (Loss)	10,000	-275,000	-3,336,000	462,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	473,000	-236,000	512,000	-721,000	'
Foreign currency gains (losses), net	0	0	0	0	'
Other Nonoperating Income (Expense)	0	0	0	0	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	0	0	6,154,000	'
Segment Profit (Loss)	483,000	-511,000	-2,824,000	5,895,000	'
Capital Expenditures	'	'	217,000	0	'
Property, Plant and Equipment, Gross	44,006,000	43,693,000	44,006,000	43,693,000	'
Accumulated depreciation	8,614,000	2,595,000	8,614,000	2,595,000	'
Property, Plant and Equipment, Net In Service	35,392,000	41,098,000	35,392,000	41,098,000	'
Construction in Progress, Gross	0	0	0	0	'
Net property and equipment	35,392,000	41,098,000	35,392,000	41,098,000	'
Investments, at Equity, and Advances to 50% or Less Owned Companies	0	0	0	0	'
Inventories	12,164,000	12,822,000	12,164,000	12,822,000	'
Goodwill	0	0	0	0	'
Intangible Assets, Net	50,000	135,000	50,000	135,000	'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	10,925,000	7,154,000	10,925,000	7,154,000	'
Total assets	58,531,000	61,209,000	58,531,000	61,209,000	'
Operating Segments [Member] | Other Segments [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	20,652,000	30,893,000	34,976,000	69,001,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Operating Expenses	18,960,000	27,566,000	33,448,000	60,643,000	'
Administrative and general	1,323,000	5,899,000	2,979,000	10,697,000	'
Depreciation and amortization	96,000	711,000	195,000	1,400,000	'
Total costs and expenses	20,379,000	34,176,000	36,622,000	72,740,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	0	1,907,000	5,000	'
Operating Income (Loss)	273,000	-3,283,000	261,000	-3,734,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	-450,000	2,516,000	392,000	1,099,000	'
Foreign currency gains (losses), net	-169,000	-84,000	-336,000	15,000	'
Other Nonoperating Income (Expense)	0	0	54,000	0	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	418,000	-371,000	2,128,000	-726,000	'
Segment Profit (Loss)	72,000	-1,222,000	2,499,000	-3,346,000	'
Capital Expenditures	'	'	357,000	6,314,000	'
Property, Plant and Equipment, Gross	3,989,000	22,704,000	3,989,000	22,704,000	'
Accumulated depreciation	531,000	3,587,000	531,000	3,587,000	'
Property, Plant and Equipment, Net In Service	3,458,000	19,117,000	3,458,000	19,117,000	'
Construction in Progress, Gross	2,087,000	2,864,000	2,087,000	2,864,000	'
Net property and equipment	5,545,000	21,981,000	5,545,000	21,981,000	'
Investments, at Equity, and Advances to 50% or Less Owned Companies	86,714,000	69,426,000	86,714,000	69,426,000	'
Inventories	1,219,000	5,362,000	1,219,000	5,362,000	'
Goodwill	0	37,138,000	0	37,138,000	'
Intangible Assets, Net	410,000	5,898,000	410,000	5,898,000	'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	56,591,000	83,664,000	56,591,000	83,664,000	'
Total assets	150,479,000	223,469,000	150,479,000	223,469,000	'
Operating Segments [Member] | Corporate And Eliminations [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	-605,000	-8,000	-1,283,000	-195,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Operating Expenses	-577,000	17,000	-1,231,000	-141,000	'
Administrative and general	8,638,000	7,544,000	17,938,000	16,607,000	'
Depreciation and amortization	753,000	466,000	1,545,000	921,000	'
Total costs and expenses	8,814,000	8,027,000	18,252,000	17,387,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	0	141,000	0	'
Operating Income (Loss)	-9,419,000	-8,035,000	-19,394,000	-17,582,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	-1,023,000	274,000	-4,161,000	-782,000	'
Foreign currency gains (losses), net	-125,000	-511,000	-561,000	-63,000	'
Other Nonoperating Income (Expense)	-4,000	175,000	-69,000	61,000	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	0	0	0	'
Capital Expenditures	'	'	1,307,000	2,781,000	'
Property, Plant and Equipment, Gross	29,221,000	26,471,000	29,221,000	26,471,000	'
Accumulated depreciation	9,709,000	10,078,000	9,709,000	10,078,000	'
Property, Plant and Equipment, Net In Service	19,512,000	16,393,000	19,512,000	16,393,000	'
Construction in Progress, Gross	1,314,000	5,672,000	1,314,000	5,672,000	'
Net property and equipment	20,826,000	22,065,000	20,826,000	22,065,000	'
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	22,225,000	35,858,000	22,225,000	35,858,000	'
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	-28,000	-83,000	52,000	52,000	'
Intersegment Eliminations [Member] | Inland River Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	-577,000	0	1,231,000	0	'
Intersegment Eliminations [Member] | Shipping Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	0	108,000	0	108,000	'
Intersegment Eliminations [Member] | Ethanol and Industrial Alcohol [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	0	0	0	0	'
Intersegment Eliminations [Member] | Other Segments [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	0	-17,000	0	35,000	'
Intersegment Eliminations [Member] | Corporate And Eliminations [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	605,000	-8,000	-1,283,000	-195,000	'
Segment Reconciling Items [Member]	'	'	'	'	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Other Income (Expense) not included in Segment Profit	-1,853,000	-8,976,000	3,825,000	-4,830,000	'
Less Equity Earnings included in Segment Profit	-7,710,000	-295,000	-6,841,000	-7,956,000	'
Cash And Near Cash Assets	589,198,000	533,439,000	589,198,000	533,439,000	'
Assets of Disposal Group, Including Discontinued Operation	'	$987,343,000	'	$987,343,000	'

Discontinued_Operations_Detail

Discontinued Operations (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Operating Revenues	$315,563	$309,225	$582,627	$607,074
Administrative and general	34,718	36,301	70,363	71,292
Depreciation and amortization	33,783	33,220	67,331	62,922
Total costs and expenses	308,614	314,066	578,720	587,178
Gain (Loss) on Sale of Assets and Asset Impairment Charges	12,305	3,342	14,320	7,119
Operating Income (Loss)	19,254	-1,499	18,227	27,015
Nonoperating Income (Expense)	307	10,949	-11,486	5,422
Income Tax Expense (Benefit)	7,975	3,250	5,322	12,710
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	7,710	295	6,841	7,956
Net Income	19,296	11,299	-2,065	47,672
SES Business [Member]	'	'	'	'
Operating Revenues	0	0	0	22,387
Operating Expenses	0	0	0	18,234
Administrative and general	0	567	0	4,587
Depreciation and amortization	0	0	0	1,428
Total costs and expenses	0	567	0	24,249
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	0	0	-71
Operating Income (Loss)	0	-567	0	-1,933
Nonoperating Income (Expense)	0	5	-1,537	24,971
Income Tax Expense (Benefit)	0	-197	-538	4,305
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	0	0	302
Net Income	0	-365	-999	19,035
SEI [Member]	'	'	'	'
Operating Revenues	0	153,388	0	316,318
Operating Expenses	0	150,837	0	310,800
Administrative and general	0	1,626	0	3,136
Depreciation and amortization	0	1	0	-4
Total costs and expenses	0	152,464	0	313,932
Operating Income (Loss)	0	924	0	2,386
Nonoperating Income (Expense)	0	1,136	-143	5
Income Tax Expense (Benefit)	0	864	-50	1,103
Net Income	0	1,196	-93	1,288
Era Group [Member]	'	'	'	'
Operating Revenues	0	62,985	22,892	124,037
Operating Expenses	0	39,002	14,076	78,678
Administrative and general	0	7,195	2,653	16,872
Depreciation and amortization	0	10,464	3,875	20,094
Total costs and expenses	0	56,661	20,604	115,644
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	1,077	548	2,842
Operating Income (Loss)	0	7,401	2,836	11,235
Nonoperating Income (Expense)	0	-2,323	-1,316	-3,136
Income Tax Expense (Benefit)	0	1,861	10,818	2,770
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	756	65	-5,663
Net Income	0	3,973	-9,233	-334
Consolidation, Eliminations [Member]	'	'	'	'
Operating Revenues	0	-31,176	0	-55,124
Operating Expenses	0	-31,174	0	-55,122
Administrative and general	0	-2	0	-2
Total costs and expenses	0	-31,176	0	-55,124
Operating Income (Loss)	$0	$0	$0	$0

Restatement_Details

Restatement (Details) (USD $)	3 Months Ended		6 Months Ended			6 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Jun. 30, 2013	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2013
						Scenario, Previously Reported [Member]	Era Group [Member]	Era Group [Member]	Era Group [Member]	Era Group [Member]	Era Group [Member]
Liability for Uncertain Tax Positions, Current	'	'	'	'	'	'	$10,100,000	'	$10,100,000	'	$10,100,000
Other current liabilities	122,424,000	'	122,424,000	'	93,093,000	112,310,000	'	'	'	'	'
Total current liabilities	220,728,000	'	220,728,000	'	265,641,000	210,614,000	'	'	'	'	'
Total liabilities	1,431,897,000	'	1,431,897,000	'	1,958,119,000	1,421,783,000	'	'	'	'	'
Retained earnings	1,056,583,000	'	1,056,583,000	'	1,473,509,000	1,066,697,000	'	'	'	'	'
Stockholders' equity attributable to parent, total	1,311,558,000	'	1,311,558,000	'	1,713,654,000	1,321,672,000	'	'	'	'	'
Total equity	1,336,436,000	'	1,336,436,000	'	1,742,675,000	1,346,550,000	'	'	'	'	'
Income (Loss) from Discontinued Operations, Net of Tax	0	4,804,000	-10,325,000	19,989,000	'	-211,000	'	'	'	'	'
Net Income	19,296,000	11,299,000	-2,065,000	47,672,000	'	8,049,000	0	3,973,000	-9,233,000	-334,000	'
Net Income attributable to SEACOR Holdings Inc.	19,271,000	11,249,000	-1,717,000	47,737,000	'	8,397,000	'	'	'	'	'
Income (Loss) from Continuing Operations Attributable to Parent	19,271,000	6,445,000	8,508,000	27,748,000	'	8,508,000	'	'	'	'	'
Discontinued operations, net of tax	0	4,804,000	-10,225,000	19,989,000	'	-111,000	'	'	'	'	'
Continuing operations	$0.97	$0.31	$0.43	$1.35	'	$0.43	'	'	'	'	'
Discontinued operations	$0	$0.24	($0.52)	$0.97	'	($0.01)	'	'	'	'	'
Earnings Per Share, Basic	$0.97	$0.55	($0.09)	$2.32	'	$0.42	'	'	'	'	'
Continuing operations	$0.91	$0.31	$0.42	$1.33	'	$0.42	'	'	'	'	'
Discontinued operations	$0	$0.23	($0.51)	$0.96	'	$0	'	'	'	'	'
Earnings Per Share, Diluted	$0.91	$0.54	($0.09)	$2.29	'	$0.42	'	'	'	'	'
Comprehensive Income	19,397,000	10,743,000	-4,719,000	49,956,000	'	5,395,000	'	'	'	'	'
Comprehensive Income attributable to SEACOR Holdings Inc.	$19,349,000	$10,787,000	($3,919,000)	$49,864,000	'	$6,195,000	'	'	'	'	'