Seacor (CKH) 10-Q/A 7 Mar 14 2013 Q1 Quarterly report (amended) Financial data

Document_And_Entity_Informatio

Document And Entity Information	3 Months Ended
	Mar. 31, 2013	Apr. 25, 2013
Document Information [Line Items]	'	'
Document Type	'10-Q	'
Document Period End Date	31-Mar-13	'
Amendment Flag	'false	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q1	'
Entity Registrant Name	'SEACOR HOLDINGS INC /NEW/	'
Entity Central Index Key	'0000859598	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	20,109,172
Entity Well-known Seasoned Issuer	'Yes	'
Entity Voluntary Filers	'No	'
Entity Current Reporting Status	'Yes	'

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Mar. 31, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Current Assets:	'		'
Cash and cash equivalents	$312,977		$248,204
Restricted cash	27,129		28,285
Marketable securities	22,568		21,668
Receivables:	'		'
Trade, net of allowance for doubtful accounts of $1,209 and $1,201 in 2013 and 2012, respectively	172,889		224,944
Other Receivables	41,139		45,334
Inventories	31,966	[1]	25,787
Deferred income taxes	3,530		3,530
Prepaid expenses and other	8,834		12,719
Discontinued operations	384		108,153
Total current assets	621,416		718,624
Property and Equipment:	'		'
Property, Plant and Equipment, Gross	2,186,892		2,238,383
Accumulated depreciation	785,765		763,803
Property, Plant and Equipment, Net In Service	1,401,127		1,474,580
Construction in Progress, Gross	113,381		110,296
Net property and equipment	1,514,508		1,584,876
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	299,778		272,535
Construction Reserve Funds & Title XI Reserve Funds	194,477		195,629
Goodwill	17,978		17,978
Intangible Assets, Net	15,754		15,305
Other Assets	51,576		55,123
Discontinued Operations	0		840,724
Total assets	2,715,487		3,700,794
Current Liabilities:	'		'
Current portion of long-term debt	15,435		21,920
Current portion of capital lease obligations	2,711		2,900
Accounts payable and accrued expenses	69,008		107,892
Other current liabilities	119,414		93,093
Discontinued operations	300		39,836
Total current liabilities	206,868		265,641
Long-Term Debt	655,384		655,309
Capital Lease Obligations	36		59
Deferred Income Taxes	422,719		426,027
Deferred Gains and Other Liabilities	116,572		120,342
Discontinued Operations	2,599		490,741
Total liabilities	1,404,178		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	369		367
Additional paid-in capital	1,340,875		1,330,324
Retained earnings	1,037,312		1,473,509
Shares held in treasury of 15,489,052 and 15,511,323 in 2012 and 2011, respectively, at cost	-1,089,064		-1,088,560
Accumulated Other Comprehensive Income (Loss), Net of Tax	-4,321		-1,986
Stockholders' equity attributable to parent, total	1,285,171		1,713,654
Noncontrolling interests in subsidiaries	26,138		29,021
Total equity	1,311,309		1,742,675
Liabilities and stockholders' equity, total	$2,715,487		$3,700,794
[1]	Inventories includes raw materials of $3.0 million and work in process of $2.4 million.

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Trade receivables, allowance for doubtful accounts	$1,209	$1,201
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
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	36,957,667	36,740,324
Treasury stock, shares	16,851,393	16,852,391

Condensed_Consolidated_Stateme

Condensed Consolidated Statements Of Income (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012
Income Statement [Abstract]	'	'
Operating Revenues	$267,064	$297,849
Costs and Expenses [Abstract]	'	'
Operating	200,913	208,419
Administrative and general	35,645	34,991
Depreciation and amortization	33,548	29,702
Total costs and expenses	270,106	273,112
Gains on Asset Dispositions and Impairments, Net	2,015	3,777
Operating Income (Loss)	-1,027	28,514
Other Income (Expense):	'	'
Interest income	3,167	2,643
Interest expense	-12,840	-9,987
Debt extinguishment losses, net	0	-160
Marketable security gains, net	3,995	3,358
Derivative losses, net	-2,107	-2,958
Foreign currency gains, net	-4,011	1,661
Other, net	3	-84
Total Other Nonoperating Income (Expense)	-11,793	-5,527
Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	-12,820	22,987
Income Tax Expense (Benefit)	-2,653	9,460
Income from Continuing Operations Before Equity in Earnings of 50% or Less Owned Companies	-10,167	13,527
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	-869	7,661
Income from Continuing Operations	-11,036	21,188
Income (Loss) from Discontinued Operations, Net of Tax	-10,325	15,185
Net Income	-21,361	36,373
Net Income (Loss) Attributable to Noncontrolling Interest	-373	-115
Net Income attributable to SEACOR Holdings Inc.	-20,988	36,488
Net Income (Loss) attributable to SEACOR Holdings Inc.:	'	'
Continuing operations	-10,763	21,303
Discontinued operations, net of tax	-10,225	15,185
Net Income attributable to SEACOR Holdings Inc.	($20,988)	$36,488
Basic Earnings Per Common Share of SEACOR Holdings Inc.	'	'
Continuing operations	($0.55)	$1.04
Discontinued operations	($0.51)	$0.74
Earnings Per Share, Basic	($1.06)	$1.78
Diluted Earnings Per Common Share of SEACOR Holdings Inc.	'	'
Continuing operations	($0.55)	$1.02
Discontinued operations	($0.51)	$0.73
Earnings Per Share, Diluted	($1.06)	$1.75
Weighted Average Common Shares Outstanding:	'	'
Basic	19,738,930	20,519,660
Weighted Average Number of Shares Outstanding, Diluted	19,738,930	20,893,210

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements Of Comprehensive Income (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012
Net Income	($21,361)	$36,373
Other Comprehensive Income (Loss):	'	'
Reclassification of net foreign currency translation losses to foreign currency gains, net	-4,198	3,200
Reclassification of foreign currency translation losses to foreign currency gains (losses), net	0	758
Other	0	42
Other Comprehensive Income (Loss), before Tax	-3,982	4,234
Income tax expense	-1,227	1,394
Other Comprehensive Income (Loss), Net of Tax	-2,755	2,840
Comprehensive Income	-24,116	39,213
Comprehensive Income attributable to Noncontrolling Interests in Subsidiaries	-848	136
Comprehensive Income attributable to SEACOR Holdings Inc.	-23,268	39,077
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	167	74
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	636
Interest Rate Swap [Member]	'	'
Other Comprehensive Income (Loss):	'	'
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	$49	($476)

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	975	0	0	0	975	0	0	'
Exercise of stock options	3,720	1	3,719	0	0	0	0	'
Director stock awards	-83	0	-83	0	0	0	0	'
Restricted stock and restricted stock units	-33	1	-34	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	5,935	0	-5,935	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	-1,968	0	0	0	0	0	-1,968	'
Comprehensive income:	'	'	'	'	'	'	'	'
Net Income (Loss) Attributable to Parent	-20,988	0	0	'	0	0	'	'
Net Income (Loss) Attributable to Noncontrolling Interest	-373	'	'	'	'	'	-373	'
Net income	-21,361	'	'	'	'	'	'	-9,233
Other comprehensive income	-2,755	0	0	0	0	-2,280	-475	'
Balance at Mar. 31, 2013	$1,311,309	$369	$1,340,875	$1,037,312	($1,089,064)	($4,321)	$26,138	'

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements Of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012
Statement of Cash Flows [Abstract]	'	'
Net Cash Provided by Operating Activities of Continuing Operations	$56,794	$67,075
Cash Flows from Investing Activities of Continuing Operations:	'	'
Purchases of property and equipment	33,855	65,332
Proceeds from disposition of property and equipment	61,369	2,883
Investments in and advances to 50% or less owned companies	-22,355	-13,546
Return of investments and advances from 50% or less owned companies	510	2,003
Net advances on revolving credit line to 50% or less owned companies	0	-300
Principal payments on third party notes receivable, net	3,079	3,367
Net decrease (increase) in restricted cash	-1,156	4,677
Net decrease in construction reserve funds and title XI reserve funds	-1,152	-48
Repayments on leases, net	-835	-955
Businesses acquisitions, net of cash acquired	0	148,139
Net cash used in investing activities of continuing operations	11,891	-222,738
Cash Flows from Financing Activities of Continuing Operations:	'	'
Payments on long term debt and capital lease obligations	2,665	60,320
Net borrowings (repayments) on inventory financing arrangements	5,519	17,312
Proceeds from issuance of long term debt, net of offering costs	0	69
Cash Received (Paid) For Share Settlements from Spinoff Transactions	-357	0
Proceeds and tax benefits from share award plans	4,658	5,261
Distributions paid to noncontrolling interests, net of issuances	1,928	333
Net cash provided by (used in) financing activities of continuing operations	-5,811	-72,635
Effect of Exchange Rate Changes on Cash and Cash Equivalents	-2,538	1,354
Net Increase (Decrease) in Cash and Cash Equivalents from Continuing Operations	60,336	-226,944
Cash Flows from Discontinued Operations:	'	'
Operating Activities	24,298	20,356
Investing Activities	-5,987	37,882
Financing Activities	-14,017	37,303
Effects of Exchange Rate Changes on Cash and Cash Equivalents	143	858
Net Increase in Cash and Cash Equivalents from Discontinued Operations	4,437	96,399
Net Increase (Decrease) in Cash and Cash Equivalents	64,773	-130,545
Cash and Cash Equivalents, Beginning of Period	248,204	381,482
Cash and Cash Equivalents, End of Period	$312,977	$250,937

Basis_of_Presentation_and_Acco

Basis of Presentation and Accounting Policy	3 Months Ended
	Mar. 31, 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 months ended March 31, 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 March 31, 2013, its results of operations for the three months ended March 31, 2013 and 2012, its comprehensive income (loss) for the three months ended March 31, 2013 and 2012, its changes in equity for the three months ended March 31, 2013, and its cash flows for the three months ended March 31, 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 shareholders 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 three months ended March 31 were as follows (in thousands):
		2013				2012
	Balance at beginning of period	$	6,592			$	9,845
	Revenues deferred during the period	—				1,132
	Revenues recognized during the period	—				(4,623		)
	Balance at end of period	$	6,592			$	6,354
	As of March 31, 2013, deferred revenues included $6.6 million relating 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 Income (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)		(3,723		)		216			—			(3,507		)	(475		)	—			$	(3,982	)
	Income tax (expense) benefit		1,303				(76		)	—			1,227			—			—			1,227
	Three months ended March 31, 2013		$	(3,713	)		$	(592	)	$	(16	)	$	(4,321	)	$	(154	)	$	(10	)	$	(2,755	)
	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 Quarterly 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 three months ended March 31, 2013 of $10.1 million (see Note 15).

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 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 March 31, 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)	$	22,568		$	—		$	—
	Derivative instruments (included in other receivables)	465			6,052			—
	Construction reserve funds and Title XI reserve funds	194,477			—			—
	LIABILITIES
	Short sale of marketable securities (included in other current liabilities)	9,610			—			—
	Derivative instruments (included in other current liabilities)	770			5,478			—
	______________________
	-1	Marketable security gains (losses), net include unrealized gains of $4.0 million and $2.0 million for the three months ended March 31, 2013 and 2012, respectively, related to marketable security positions held by the Company as of March 31, 2013.
	The estimated fair values of the Company’s other financial assets and liabilities as of March 31, 2013 were as follows (in thousands):
					Estimated Fair Value
		Carrying			Level 1			Level 2			Level 3
		Amount
	ASSETS
	Cash, cash equivalents and restricted cash	$	340,106		$	340,106		$	—		$	—
	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	22,990			see below
	receivables and other assets)
	LIABILITIES
	Long-term debt, including current portion	670,819			—			783,655			—
	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 three months ended March 31 were as follows (in thousands):
			Level 1			Level 2			Level 3
	2013
	ASSETS
	Long-lived assets under construction(1)		$	17,494		$	—		$	—
	______________________
	-1	During the three months ended March 31, 2013, the Company recognized impairment charges of $3.0 million related to two of Shipping Services harbor tugs, which are currently under construction and anticipated to be sold and leased back upon completion (see Note 5).

Derivative_Instruments_And_Hed

Derivative Instruments And Hedging Strategies	3 Months Ended
	Mar. 31, 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 March 31, 2013 were as follows (in thousands):
		Derivative			Derivative
		Asset			Liability
	Options on equities and equity indices	$	234		$	182
	Forward currency exchange, option and future contracts	209			886
	Interest rate swap agreements	—			4,561
	Commodity swap, option and future contracts:
	Exchange traded	465			589
	Non-exchange traded	5,609			30
		$	6,517		$	6,248
	Cash Flow Hedges. As of March 31, 2013, the Company had no interest rate swap agreements designated as cash flow hedges. As of March 31, 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 $17.8 million and receive a variable interest rate based on LIBOR on the amortized notional value. As of March 31, 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 $42.2 million and receive a variable interest rate based on LIBOR on the aggregate amortized notional value. Additionally, as of March 31, 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 $38.9 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 three months ended March 31 as follows (in thousands):
		2013			2012
	Interest rate swap agreements, effective portion in other comprehensive income (loss)	$	49		$	(476	)
	Interest rate swap agreements, ineffective portion in derivative losses, net	—			(28		)
		$	49		$	(504	)
	Other Derivative Instruments. The Company recognized gains (losses) on derivative instruments not designated as hedging instruments in derivative losses, net for the three months ended March 31 as follows (in thousands):
		2013			2012
	Options on equities and equity indices	$	(2,284	)	$	(1,212	)
	Forward currency exchange, option and future contracts	(598		)	583
	Interest rate swap agreements	89			(209		)
	Commodity swap, option and future contracts:
	Exchange traded	(744		)	(993		)
	Non-exchange traded	1,430			(1,099		)
	U.S. Treasury notes, rate-locks and bond future and option contracts	—			—
		$	(2,107	)	$	(2,930	)
	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 March 31, 2013, the outstanding forward currency exchange contracts translated into a net purchase of foreign currencies with an aggregate U.S. dollar equivalent of $13.6 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 3.00% on an aggregate amortized notional value of $198.8 million (including an amortized notional value of €11.9 million or $15.3 million) and receive a variable interest rate based on LIBOR on these notional values. In addition, two of the Company’s Offshore Marine Services 50% or less owned companies have entered into interest rate swap agreements maturing in 2014 and 2018 that call for the joint venture to pay fixed interest rates of 3.05% and 1.30%, on the amortized notional values of $24.0 million and $108.0 million, respectively, and receive a variable interest rate based on LIBOR on the amortized notional values. 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 March 31, 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 March 31, 2013, these positions were not material.

Business_Acquisitions

Business Acquisitions	3 Months Ended
	Mar. 31, 2013
Business Combinations [Abstract]	'
Business Acquisitions	'
	BUSINESS ACQUISITIONS
	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 three months ended March 31, 2013 (in thousands):
	Property and Equipment	$	(1,599	)
	Intangible Assets	1,599
	Purchase price	$	—

Equipment_Acquisitions_Disposi

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies	3 Months Ended
	Mar. 31, 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 three months ended March 31, 2013, capital expenditures were $33.9 million. Equipment deliveries during the period included two offshore support vessels, including one wind farm utility vessel, and one liquid tank barge.
	During the three months ended March 31, 2013, the Company sold two offshore support vessels and other property and equipment for net proceeds of $68.4 million ($61.3 million in cash and $7.1 million in seller financing) and gains of $4.3 million, all of which were recognized currently. In addition, the Company recognized previously deferred gains of $0.7 million. The two offshore support vessels were sold to certain of the Company's Offshore Marine Services' joint ventures for $60.5 million (see Note 6).
	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 three months ended March 31 was as follows (in thousands):
		2013			2012
	Balance at beginning of period	$	111,514		$	117,192
	Deferred gains arising from asset sales	—			—
	Amortization of deferred gains included in operating expenses as a reduction to rental expense	(2,801		)	(4,925		)
	Amortization of deferred gains included in gains on asset dispositions and impairments, net	(716		)	(801		)
	Balance at end of period	$	107,997		$	111,466
	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 March 31, 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 three months ended March 31, 2013, the Company recognized impairment charges of $3.0 million related to two of Shipping Services harbor tugs, which are currently under construction and anticipated to be sold and leased back upon completion.

Investments_At_Equity_And_Adva

Investments, At Equity, And Advances To 50% Or Less Owned Companies	3 Months Ended
	Mar. 31, 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
	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 three months ended March 31, 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 three months ended March 31, 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). As of March 31, 2013, $6.1 million was outstanding on the seller financing, inclusive of unpaid accrued interest, all of which was repaid in April 2013.
	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 three months ended March 31, 2013, the Company contributed additional capital of $1.4 million to fund SCFCo’s operations and provided net temporary working capital advances of $0.5 million. As of March 31, 2013, the total outstanding balance of working capital advances by the Company was $2.8 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 three months ended March 31, 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 March 31, 2013, the total outstanding balance of working capital advances was $7.0 million.
	Other. During the three months ended March 31, 2013, the Company made a $0.5 million capital contribution to one of its industrial aviation businesses in Asia.
	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 March 31, 2013, the total amount guaranteed by the Company under these arrangements was $26.6 million. In addition, as of March 31, 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	3 Months Ended
	Mar. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments And Contingencies	'
	COMMITMENTS AND CONTINGENCIES
	As of March 31, 2013, the Company’s unfunded capital commitments were $151.8 million and included: fourteen offshore support vessels for $106.1 million; seven inland river liquid tank barges for $15.0 million; five inland river towboats for $12.7 million; four harbor tugs for $7.4 million and other equipment and improvements for $8.0 million. In addition, the Company notified a lessor of its intent to purchase two harbor tugs currently operating under capital leases for $2.6 million. Of these commitments, $97.8 million is payable during the remainder of 2013 with the balance payable through 2015. Subsequent to March 31, 2013, the Company committed to purchase additional equipment for $49.7 million.
	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 Unites States Court of Appeals for the 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's response is due on April 30, 2013. The Company is unable to estimate the potential exposure, if any, resulting from this matter and intends to vigorously defend the action should it ever proceed. The Company does not expect this matter will have a material effect on the Company's consolidated financial position or its results of operations. In addition, the responsible party has agreed, subject to certain potential limitations, to indemnify and defend the Company in connection with this matter.
	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. 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.
	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.
	Subsequent to the filing of the referenced master complaint, eight additional individual civil actions have been filed in 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). 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. Finally, 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. By court order, all eight 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 they will have a material effect on the Company's 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 provided 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 these matters will have a material effect on the Company's 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. The Company is unable to estimate the potential exposure, if any, resulting from this matter but believes it is without merit and does not expect this matter to have a material effect on the Company's 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. Notices of Appeal to the Fifth Circuit with respect to both class action settlements have been filed by various objectors. 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, but is currently still evaluating 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.
	In the course of the Company's business, it may agree to indemnify a party.  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 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.
	ORM is defending against four 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”); Himmerite et al. v. O'Brien's Response Management Inc. et al. (E.D. La., Case No.: 2:12-cv-01533) (the “Himmerite Action”); and Chann Chavis v. O'Brien's Response Management Inc. et al. (S.D. Tx., Case No.: 4:12-cv-02045) (the “Chavis 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, which has been stayed pending further scheduling by the Court in accordance with the procedures of the MDL. 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 Chavis Action was filed on July 7, 2012 in the United States District Court for the Southern District of Texas. On December 20, 2012, the parties in the Chavis Action entered into a full and final settlement agreement with respect to all of the Plaintiff's individual and class claims, and the Court issued an order approving this settlement on March 11, 2013. 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 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	3 Months Ended
	Mar. 31, 2013
Compensation and Retirement Disclosure [Abstract]	'
Multiemployer Pension Plans	'
	MULTI-EMPLOYER PENSION PLANS
	There has been no material change in the multi-employer pension plans in which the Company participates, except that 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 March 31, 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.

LongTerm_Debt_and_Capital_Leas

Long-Term Debt and Capital Lease Obligations	3 Months Ended
	Mar. 31, 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 March 31, 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 March 31, 2013, the Company had other outstanding letters of credit totaling $29.1 million with various expiration dates through 2016.
	During the three months ended March 31, 2013, the Company made scheduled payments on other long-term debt and capital lease obligations of $2.7 million and made net repayments of $5.5 million on 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 three months ended March 31, 2013, the Company did not repurchase any of its 7.375% Senior Notes due 2019.

Stock_Repurchases

Stock Repurchases	3 Months Ended
	Mar. 31, 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 three months ended March 31, 2013, the Company did not acquire any shares of Common Stock for treasury. As of March 31, 2013, the remaining authority under the repurchase plan was $100.0 million.

Earnings_Per_Common_Share_of_S

Earnings Per Common Share of SEACOR	3 Months Ended
	Mar. 31, 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 for the three months ended March 31, were as follows (in thousands, except share data):
		Net Income (Loss) Attributable to SEACOR			Average O/S Shares	Per Share
		(As Restated)				(As Restated)
	2013
	Basic Weighted Average Common Shares Outstanding	$	(20,988	)	19,738,930	$	(1.06	)
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—			—
	Convertible Securities(2)	—			—
	Diluted Weighted Average Common Shares Outstanding	$	(20,988	)	19,738,930	$	(1.06	)
		Net Income (Loss) Attributable to SEACOR			Average O/S Shares	Per Share
	2012
	Basic Weighted Average Common Shares Outstanding	$	36,488		20,519,660	$	1.78
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—			373,550
	Diluted Weighted Average Common Shares Outstanding	$	36,488		20,893,210	$	1.75
	______________________
	-1	For the three months ended March 31, 2013 and 2012, diluted earnings per common share of SEACOR excluded 1,474,897 and 501,274 of certain share awards, respectively, as the effect of their inclusion in the computation would be anti-dilutive.
	-2	Excludes interest expense of $4.6 million, net of tax, and 4,200,525 shares related to the Company's 2.5% Convertible Senior Notes as the their inclusion would be anti-dilutive.

Share_Based_Compensation

Share Based Compensation	3 Months Ended
	Mar. 31, 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 three months ended March 31, 2013 were as follows:
	Director stock awards granted	1,000
	Employee Stock Purchase Plan (“ESPP”) shares issued	17,998
	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	368,612
	Exercised	(68,543	)
	Forfeited	—
	Expired	(1,576	)
	Outstanding as of March 31, 2013	1,580,314
	Shares available for future grants and ESPP purchases as of March 31, 2013	1,001,595
	______________________
	-1	During the three months ended March 31, 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	3 Months Ended
	Mar. 31, 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 Note 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(1)(2)				Eliminations
		$’000		$’000				$’000				$’000
	For the three months ended
	31-Mar-13
	Operating Revenues:
	External customers	123,992		49,423		46,476		32,849		14,324		—		267,064
	Intersegment	24		654		—		—		—		(678	)	—
		124,016		50,077		46,476		32,849		14,324		(678	)	267,064
	Costs and Expenses:
	Operating	90,031		36,389		26,614		34,045		14,488		(654	)	200,913
	Administrative and general	14,827		4,024		5,177		661		1,656		9,300		35,645
	Depreciation and amortization	16,287		7,084		7,797		1,489		99		792		33,548
		121,145		47,497		39,588		36,195		16,243		9,438		270,106
	Gains (Losses) on Asset Dispositions	2,339		697		(3,069	)	—		1,907		141		2,015
	and Impairments, Net
	Operating Income (Loss)	5,210		3,277		3,819		(3,346	)	(12	)	(9,975	)	(1,027	)
	Other Income (Expense):
	Derivative gains (losses), net	150		—		—		39		842		(3,138	)	(2,107	)
	Foreign currency gains (losses), net	(3,264	)	(137	)	(7	)	—		(167	)	(436	)	(4,011	)
	Other, net	—		—		14		—		54		(65	)	3
	Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,313		(2,387	)	(1,505	)	—		1,710		—		(869	)
	Segment Profit (Loss)	3,409		753		2,321		(3,307	)	2,427
	Other Income (Expense) not included in Segment Profit (Loss)													(5,678	)
	Plus Equity Earnings (Losses) included in Segment Profit (Loss)													869
	Loss Before Taxes, Equity Losses and Discontinued Operations													(12,820	)
	Capital Expenditures	19,920		5,727		6,814		—		357		1,037		33,855
	As of March 31, 2013
	Property and Equipment:
	Historical cost	1,110,480		493,140		506,279		43,788		4,032		29,173		2,186,892
	Accumulated depreciation	(428,766	)	(133,827	)	(206,603	)	(7,146	)	(467	)	(8,956	)	(785,765	)
		681,714		359,313		299,676		36,642		3,565		20,217		1,401,127
	Construction in progress	61,447		15,335		33,444		—		2,063		1,092		113,381
		743,161		374,648		333,120		36,642		5,628		21,309		1,514,508
	Investments, at Equity, and Advances to 50% or Less Owned Companies	85,311		55,105		65,941		—		93,421		—		299,778
	Inventories	6,497		2,297		1,284		19,868		2,020		—		31,966
	Goodwill	13,367		2,759		1,852		—		—		—		17,978
	Intangible Assets	5,105		8,824		1,272		72		481		—		15,754
	Other current and long-term assets, excluding cash and near cash assets(3)	136,661		37,787		18,316		5,947		47,877		31,380		277,968
	Segment Assets	990,102		481,420		421,785		62,529		149,427
	Cash and near cash assets(3)													557,151
	Discontinued operations													384
	Total Assets													2,715,487
	______________________
	-1	Operating revenues includes $32.1 million of tangible product sales and operating expenses includes $34.4 million of costs of goods sold.
	-2	Inventories includes raw materials of $3.0 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.
		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 three months ended
	31-Mar-12
	Operating Revenues:
	External customers	120,951		53,490		45,733		39,619		38,056		—		297,849
	Intersegment	135		—		—		—		52		(187	)	—
		121,086		53,490		45,733		39,619		38,108		(187	)	297,849
	Costs and Expenses:
	Operating	75,340		35,183		27,572		37,405		33,077		(158	)	208,419
Administrative and general	11,856		3,982		4,867		425		4,798		9,063		34,991
Depreciation and amortization	12,882		7,007		7,617		1,052		689		455		29,702
	100,078		46,172		40,056		38,882		38,564		9,360		273,112
Gains on Asset Dispositions, Net	1,845		1,927		—		—		5		—		3,777
Operating Income (Loss)	22,853		9,245		5,677		737		(451	)	(9,547	)	28,514
Other Income (Expense):
Derivative losses, net	—		—		—		(485	)	(1,417	)	(1,056	)	(2,958	)
Foreign currency gains (losses), net	1,123		(22	)	13		—		99		448		1,661
Other, net	—		—		30		—		—		(114	)	(84	)
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,829		250		(217	)	6,154		(355	)	—		7,661
Segment Profit (Loss)	25,805		9,473		5,503		6,406		(2,124	)
Other Income (Expense) not included in Segment Profit (Loss)													(4,146	)
Less Equity Earnings (Losses) included in Segment Profit (Loss)													(7,661	)
Income Before Taxes, Equity Earnings and Discontinued Operations													22,987
Capital Expenditures	42,778		4,884		10,543		—		6,106		1,021		65,332
As of March 31, 2012
Property and Equipment:
Historical cost	1,120,414		474,013		525,497		43,693		22,316		26,226		2,212,159
Accumulated depreciation	(386,583	)	(109,715	)	(183,461	)	(1,038	)	(3,271	)	(10,047	)	(694,115	)
	733,831		364,298		342,036		42,655		19,045		16,179		1,518,044
Construction in progress	92,322		11,670		27,419		—		2,676		4,591		138,678
	826,153		375,968		369,455		42,655		21,721		20,770		1,656,722
Investments, at Equity, and Advances to 50% or Less Owned Companies	68,645		50,758		11,989		—		48,539		—		179,931
Inventories	6,261		2,681		1,476		15,178		6,369		—		31,965
Goodwill	13,367		4,345		1,852		—		37,138		—		56,702
Intangible Assets	5,500		8,755		1,811		157		5,909		—		22,132
Other current and long-term assets, excluding cash and near cash assets(3)	140,019		61,675		15,564		6,726		104,243		17,238		345,465
Segment Assets	1,059,945		504,182		402,147		64,716		223,919
Cash and near cash assets(3)													605,407
Discontinued operations													1,008,629
Total Assets													3,906,953
______________________
-1	Operating revenues includes $38.9 million of tangible product sales and operating expenses includes $38.0 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)	3 Months Ended
	Mar. 31, 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 for the three months ended March 31 were as follows (in thousands):
			2013			2012
			(As Restated)
	SES Business
	Operating Revenues		$	—		$	22,387
	Costs and Expenses:
	Operating		—			18,234
	Administrative and general		—			4,020
	Depreciation and amortization		—			1,428
			—			23,682
	Losses on Asset Dispositions		—			(71		)
	Operating Loss		—			(1,366		)
	Other Income (Expense), Net (including gain on sale of business)		(1,537		)	24,966
	Income Tax Expense (Benefit)		(538		)	4,502
	Equity in Earnings of 50% or Less Owned Companies		—			302
	Net Income (Loss)		$	(999	)	$	19,400
	SEI
	Operating Revenues		$	—		$	162,930
	Costs and Expenses:
	Operating		—			159,963
	Administrative and general		—			1,510
	Depreciation and amortization		—			(5		)
			—			161,468
	Operating Income		—			1,462
	Other Income (Expense), Net (including gain on sale of business)		(143		)	(1,131		)
	Income Tax Expense (Benefit)		(50		)	239
	Net Income (Loss)		$	(93	)	$	92
	Era Group
	Operating Revenues		$	22,892		$	61,052
	Costs and Expenses:
	Operating		14,076			39,676
	Administrative and general		2,653			9,677
	Depreciation and amortization		3,875			9,630
			20,604			58,983
	Gains on Asset Dispositions and Impairments, Net		548			1,765
	Operating Income		2,836			3,834
	Other Income (Expense), Net		(1,316		)	(813		)
	Income Tax Expense(1)		10,818			909
	Equity in Earnings (Losses) of 50% or Less Owned Companies		65			(6,419		)
	Net Income (Loss)		$	(9,233	)	$	(4,307	)
	Eliminations
	Operating Revenues		$	—		$	(23,948	)
	Costs and Expenses:
	Operating		—			(23,948		)
	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 three months ended March 31, 2013 in the table included herein (see Note 15).

Restatement_Notes

Restatement (Notes)	3 Months Ended
	Mar. 31, 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 Quarterly 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 three months ended March 31, 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 three months ended March 31, 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):
			March 31, 2013			March 31, 2013
			(As Restated)			(As Previously Reported)
	Balance Sheet (unaudited):
	Other current liabilities		$	119,414		$	109,300
	Total current liabilities		206,868			196,754
	Total liabilities		1,404,178			1,394,064
	Retained earnings		1,037,312			1,047,426
	SEACOR Holdings Inc. stockholders' equity		1,285,171			1,295,285
	Total equity		1,311,309			1,321,423
			For the Three Months Ended
			March 31, 2013			March 31, 2013
			(As Restated)			(As Previously Reported)
	Statement of Income (Loss) (unaudited):
	Loss from Discontinued Operations, Net of Tax		$	(10,325	)	$	(211	)
	Net Loss		(21,361		)	(11,247		)
	Net Loss attributable to SEACOR Holdings Inc.		(20,988		)	(10,874		)
	Net Loss attributable to SEACOR Holdings Inc.:
	Continuing operations		$	(10,763	)	$	(10,763	)
	Discontinued operations		(10,225		)	(111		)
			$	(20,988	)	$	(10,874	)
	Basic Loss Per Common Share of SEACOR Holdings Inc.:
	Continuing operations		$	(0.55	)	$	(0.55	)
	Discontinued operations		(0.51		)	—
			$	(1.06	)	$	(0.55	)
	Diluted Loss Per Common Share of SEACOR Holdings Inc.:
	Continuing operations		$	(0.55	)	$	(0.55	)
	Discontinued operations		(0.51		)	—
			$	(1.06	)	$	(0.55	)
	Statement of Comprehensive Income (Loss) (unaudited):
	Net Loss		$	(21,361	)	$	(11,247	)
	Comprehensive Loss		(24,116		)	(14,002		)
	Comprehensive Loss attributable to SEACOR Holdings Inc.		(23,268		)	(13,154		)

Basis_of_Presentation_and_Acco1

Basis of Presentation and Accounting Policy (Policy)	3 Months Ended
	Mar. 31, 2013
Nature Of Operations And Accounting Policies [Abstract]	'
Basis Of Consolidation	'
	The condensed consolidated financial information for the three months ended March 31, 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 March 31, 2013, its results of operations for the three months ended March 31, 2013 and 2012, its comprehensive income (loss) for the three months ended March 31, 2013 and 2012, its changes in equity for the three months ended March 31, 2013, and its cash flows for the three months ended March 31, 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 shareholders 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 three months ended March 31 were as follows (in thousands):
		2013				2012
	Balance at beginning of period	$	6,592			$	9,845
	Revenues deferred during the period	—				1,132
	Revenues recognized during the period	—				(4,623		)
	Balance at end of period	$	6,592			$	6,354
	As of March 31, 2013, deferred revenues included $6.6 million relating 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 Quarterly 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 three months ended March 31, 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 three months ended March 31, 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):
			March 31, 2013				March 31, 2013
			(As Restated)				(As Previously Reported)
	Balance Sheet (unaudited):
	Other current liabilities		$	119,414			$	109,300
	Total current liabilities		206,868				196,754
	Total liabilities		1,404,178				1,394,064
	Retained earnings		1,037,312				1,047,426
	SEACOR Holdings Inc. stockholders' equity		1,285,171				1,295,285
	Total equity		1,311,309				1,321,423
			For the Three Months Ended
			March 31, 2013				March 31, 2013
			(As Restated)				(As Previously Reported)
	Statement of Income (Loss) (unaudited):
	Loss from Discontinued Operations, Net of Tax		$	(10,325	)		$	(211	)
	Net Loss		(21,361		)		(11,247		)
	Net Loss attributable to SEACOR Holdings Inc.		(20,988		)		(10,874		)
	Net Loss attributable to SEACOR Holdings Inc.:
	Continuing operations		$	(10,763	)		$	(10,763	)
	Discontinued operations		(10,225		)		(111		)
			$	(20,988	)		$	(10,874	)
	Basic Loss Per Common Share of SEACOR Holdings Inc.:
	Continuing operations		$	(0.55	)		$	(0.55	)
	Discontinued operations		(0.51		)		—
			$	(1.06	)		$	(0.55	)
	Diluted Loss Per Common Share of SEACOR Holdings Inc.:
	Continuing operations		$	(0.55	)		$	(0.55	)
	Discontinued operations		(0.51		)		—
			$	(1.06	)		$	(0.55	)
	Statement of Comprehensive Income (Loss) (unaudited):
	Net Loss		$	(21,361	)		$	(11,247	)
	Comprehensive Loss		(24,116		)		(14,002		)
	Comprehensive Loss attributable to SEACOR Holdings Inc.		(23,268		)		(13,154		)

Basis_of_Presentation_and_Acco2

Basis of Presentation and Accounting Policy (Tables)	3 Months Ended
	Mar. 31, 2013
Nature Of Operations And Accounting Policies [Abstract]	'
Deferred Revenues Included In Other Current Liabilities	'
	Deferred revenues, included in other current liabilities, for the three months ended March 31 were as follows (in thousands):
		2013				2012
	Balance at beginning of period	$	6,592			$	9,845
	Revenues deferred during the period	—				1,132
	Revenues recognized during the period	—				(4,623		)
	Balance at end of period	$	6,592			$	6,354
Comprehensive Income (Loss) Note [Text Block]	'
	Accumulated Other Comprehensive Income (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)		(3,723		)		216			—			(3,507		)	(475		)	—			$	(3,982	)
	Income tax (expense) benefit		1,303				(76		)	—			1,227			—			—			1,227
	Three months ended March 31, 2013		$	(3,713	)		$	(592	)	$	(16	)	$	(4,321	)	$	(154	)	$	(10	)	$	(2,755	)

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 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)	$	22,568		$	—		$	—
	Derivative instruments (included in other receivables)	465			6,052			—
	Construction reserve funds and Title XI reserve funds	194,477			—			—
	LIABILITIES
	Short sale of marketable securities (included in other current liabilities)	9,610			—			—
	Derivative instruments (included in other current liabilities)	770			5,478			—
	______________________
	-1	Marketable security gains (losses), net include unrealized gains of $4.0 million and $2.0 million for the three months ended March 31, 2013 and 2012, respectively, related to marketable security positions held by the Company as of March 31, 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 March 31, 2013 were as follows (in thousands):
					Estimated Fair Value
		Carrying			Level 1			Level 2			Level 3
		Amount
	ASSETS
	Cash, cash equivalents and restricted cash	$	340,106		$	340,106		$	—		$	—
	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	22,990			see below
	receivables and other assets)
	LIABILITIES
	Long-term debt, including current portion	670,819			—			783,655			—
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 three months ended March 31 were as follows (in thousands):
			Level 1			Level 2			Level 3
	2013
	ASSETS
	Long-lived assets under construction(1)		$	17,494		$	—		$	—
	______________________
	-1	During the three months ended March 31, 2013, the Company recognized impairment charges of $3.0 million related to two of Shipping Services harbor tugs, which are currently under construction and anticipated to be sold and leased back upon completion (see Note 5).

Derivative_Instruments_And_Hed1

Derivative Instruments And Hedging Strategies (Tables)	3 Months Ended
	Mar. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Fair Values Of Derivative Instruments	'
	The fair values of the Company’s derivative instruments as of March 31, 2013 were as follows (in thousands):
		Derivative			Derivative
		Asset			Liability
	Options on equities and equity indices	$	234		$	182
	Forward currency exchange, option and future contracts	209			886
	Interest rate swap agreements	—			4,561
	Commodity swap, option and future contracts:
	Exchange traded	465			589
	Non-exchange traded	5,609			30
		$	6,517		$	6,248
Recognized Gains (Losses) On Derivative Instruments Designated As Fair Value Hedges	'
Recognized Gains (Losses) On Derivative Instruments Designated As Cash Flow Hedges	'
	The Company recognized gains (losses) on derivative instruments designated as cash flow hedges for the three months ended March 31 as follows (in thousands):
		2013			2012
	Interest rate swap agreements, effective portion in other comprehensive income (loss)	$	49		$	(476	)
	Interest rate swap agreements, ineffective portion in derivative losses, net	—			(28		)
		$	49		$	(504	)
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 losses, net for the three months ended March 31 as follows (in thousands):
		2013			2012
	Options on equities and equity indices	$	(2,284	)	$	(1,212	)
	Forward currency exchange, option and future contracts	(598		)	583
	Interest rate swap agreements	89			(209		)
	Commodity swap, option and future contracts:
	Exchange traded	(744		)	(993		)
	Non-exchange traded	1,430			(1,099		)
	U.S. Treasury notes, rate-locks and bond future and option contracts	—			—
		$	(2,107	)	$	(2,930	)

Business_Acquisitions_Tables

Business Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2013
Business Combination, Description [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 three months ended March 31, 2013 (in thousands):
	Property and Equipment	$	(1,599	)
	Intangible Assets	1,599
	Purchase price	$	—

Equipment_Acquisitions_Disposi1

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies (Tables)	3 Months Ended
	Mar. 31, 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 three months ended March 31 was as follows (in thousands):
		2013			2012
	Balance at beginning of period	$	111,514		$	117,192
	Deferred gains arising from asset sales	—			—
	Amortization of deferred gains included in operating expenses as a reduction to rental expense	(2,801		)	(4,925		)
	Amortization of deferred gains included in gains on asset dispositions and impairments, net	(716		)	(801		)
	Balance at end of period	$	107,997		$	111,466
Schedule of Estimated Useful Life of Newly Acquired Equipment [Table Text Block]	'
	As of March 31, 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)	3 Months Ended
	Mar. 31, 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 for the three months ended March 31, were as follows (in thousands, except share data):
		Net Income (Loss) Attributable to SEACOR			Average O/S Shares	Per Share
		(As Restated)				(As Restated)
	2013
	Basic Weighted Average Common Shares Outstanding	$	(20,988	)	19,738,930	$	(1.06	)
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—			—
	Convertible Securities(2)	—			—
	Diluted Weighted Average Common Shares Outstanding	$	(20,988	)	19,738,930	$	(1.06	)
		Net Income (Loss) Attributable to SEACOR			Average O/S Shares	Per Share
	2012
	Basic Weighted Average Common Shares Outstanding	$	36,488		20,519,660	$	1.78
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—			373,550
	Diluted Weighted Average Common Shares Outstanding	$	36,488		20,893,210	$	1.75
	______________________
	-1	For the three months ended March 31, 2013 and 2012, diluted earnings per common share of SEACOR excluded 1,474,897 and 501,274 of certain share awards, respectively, as the effect of their inclusion in the computation would be anti-dilutive.
	-2	Excludes interest expense of $4.6 million, net of tax, and 4,200,525 shares related to the Company's 2.5% Convertible Senior Notes as the their inclusion would be anti-dilutive.

Share_Based_Compensation_Table

Share Based Compensation (Tables)	3 Months Ended
	Mar. 31, 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 three months ended March 31, 2013 were as follows:
	Director stock awards granted	1,000
	Employee Stock Purchase Plan (“ESPP”) shares issued	17,998
	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	368,612
	Exercised	(68,543	)
	Forfeited	—
	Expired	(1,576	)
	Outstanding as of March 31, 2013	1,580,314
	Shares available for future grants and ESPP purchases as of March 31, 2013	1,001,595

Segment_Information_Tables

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2013
Segment Reporting [Abstract]	'
Operating Results, Capital Expenditures And Assets By Reporting Segment	'
	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 Note 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(1)(2)				Eliminations
		$’000		$’000				$’000				$’000
	For the three months ended
	31-Mar-13
	Operating Revenues:
	External customers	123,992		49,423		46,476		32,849		14,324		—		267,064
	Intersegment	24		654		—		—		—		(678	)	—
		124,016		50,077		46,476		32,849		14,324		(678	)	267,064
	Costs and Expenses:
	Operating	90,031		36,389		26,614		34,045		14,488		(654	)	200,913
	Administrative and general	14,827		4,024		5,177		661		1,656		9,300		35,645
	Depreciation and amortization	16,287		7,084		7,797		1,489		99		792		33,548
		121,145		47,497		39,588		36,195		16,243		9,438		270,106
	Gains (Losses) on Asset Dispositions	2,339		697		(3,069	)	—		1,907		141		2,015
	and Impairments, Net
	Operating Income (Loss)	5,210		3,277		3,819		(3,346	)	(12	)	(9,975	)	(1,027	)
	Other Income (Expense):
	Derivative gains (losses), net	150		—		—		39		842		(3,138	)	(2,107	)
	Foreign currency gains (losses), net	(3,264	)	(137	)	(7	)	—		(167	)	(436	)	(4,011	)
	Other, net	—		—		14		—		54		(65	)	3
	Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,313		(2,387	)	(1,505	)	—		1,710		—		(869	)
	Segment Profit (Loss)	3,409		753		2,321		(3,307	)	2,427
	Other Income (Expense) not included in Segment Profit (Loss)													(5,678	)
	Plus Equity Earnings (Losses) included in Segment Profit (Loss)													869
	Loss Before Taxes, Equity Losses and Discontinued Operations													(12,820	)
	Capital Expenditures	19,920		5,727		6,814		—		357		1,037		33,855
	As of March 31, 2013
	Property and Equipment:
	Historical cost	1,110,480		493,140		506,279		43,788		4,032		29,173		2,186,892
	Accumulated depreciation	(428,766	)	(133,827	)	(206,603	)	(7,146	)	(467	)	(8,956	)	(785,765	)
		681,714		359,313		299,676		36,642		3,565		20,217		1,401,127
	Construction in progress	61,447		15,335		33,444		—		2,063		1,092		113,381
		743,161		374,648		333,120		36,642		5,628		21,309		1,514,508
	Investments, at Equity, and Advances to 50% or Less Owned Companies	85,311		55,105		65,941		—		93,421		—		299,778
	Inventories	6,497		2,297		1,284		19,868		2,020		—		31,966
	Goodwill	13,367		2,759		1,852		—		—		—		17,978
	Intangible Assets	5,105		8,824		1,272		72		481		—		15,754
	Other current and long-term assets, excluding cash and near cash assets(3)	136,661		37,787		18,316		5,947		47,877		31,380		277,968
	Segment Assets	990,102		481,420		421,785		62,529		149,427
	Cash and near cash assets(3)													557,151
	Discontinued operations													384
	Total Assets													2,715,487
	______________________
	-1	Operating revenues includes $32.1 million of tangible product sales and operating expenses includes $34.4 million of costs of goods sold.
	-2	Inventories includes raw materials of $3.0 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.
		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 three months ended
	31-Mar-12
	Operating Revenues:
	External customers	120,951		53,490		45,733		39,619		38,056		—		297,849
	Intersegment	135		—		—		—		52		(187	)	—
		121,086		53,490		45,733		39,619		38,108		(187	)	297,849
	Costs and Expenses:
	Operating	75,340		35,183		27,572		37,405		33,077		(158	)	208,419
	Administrative and general	11,856		3,982		4,867		425		4,798		9,063		34,991
Depreciation and amortization	12,882		7,007		7,617		1,052		689		455		29,702
	100,078		46,172		40,056		38,882		38,564		9,360		273,112
Gains on Asset Dispositions, Net	1,845		1,927		—		—		5		—		3,777
Operating Income (Loss)	22,853		9,245		5,677		737		(451	)	(9,547	)	28,514
Other Income (Expense):
Derivative losses, net	—		—		—		(485	)	(1,417	)	(1,056	)	(2,958	)
Foreign currency gains (losses), net	1,123		(22	)	13		—		99		448		1,661
Other, net	—		—		30		—		—		(114	)	(84	)
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,829		250		(217	)	6,154		(355	)	—		7,661
Segment Profit (Loss)	25,805		9,473		5,503		6,406		(2,124	)
Other Income (Expense) not included in Segment Profit (Loss)													(4,146	)
Less Equity Earnings (Losses) included in Segment Profit (Loss)													(7,661	)
Income Before Taxes, Equity Earnings and Discontinued Operations													22,987
Capital Expenditures	42,778		4,884		10,543		—		6,106		1,021		65,332
As of March 31, 2012
Property and Equipment:
Historical cost	1,120,414		474,013		525,497		43,693		22,316		26,226		2,212,159
Accumulated depreciation	(386,583	)	(109,715	)	(183,461	)	(1,038	)	(3,271	)	(10,047	)	(694,115	)
	733,831		364,298		342,036		42,655		19,045		16,179		1,518,044
Construction in progress	92,322		11,670		27,419		—		2,676		4,591		138,678
	826,153		375,968		369,455		42,655		21,721		20,770		1,656,722
Investments, at Equity, and Advances to 50% or Less Owned Companies	68,645		50,758		11,989		—		48,539		—		179,931
Inventories	6,261		2,681		1,476		15,178		6,369		—		31,965
Goodwill	13,367		4,345		1,852		—		37,138		—		56,702
Intangible Assets	5,500		8,755		1,811		157		5,909		—		22,132
Other current and long-term assets, excluding cash and near cash assets(3)	140,019		61,675		15,564		6,726		104,243		17,238		345,465
Segment Assets	1,059,945		504,182		402,147		64,716		223,919
Cash and near cash assets(3)													605,407
Discontinued operations													1,008,629
Total Assets													3,906,953
______________________
-1	Operating revenues includes $38.9 million of tangible product sales and operating expenses includes $38.0 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)	3 Months Ended
	Mar. 31, 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 for the three months ended March 31 were as follows (in thousands):
			2013			2012
			(As Restated)
	SES Business
	Operating Revenues		$	—		$	22,387
	Costs and Expenses:
	Operating		—			18,234
	Administrative and general		—			4,020
	Depreciation and amortization		—			1,428
			—			23,682
	Losses on Asset Dispositions		—			(71		)
	Operating Loss		—			(1,366		)
	Other Income (Expense), Net (including gain on sale of business)		(1,537		)	24,966
	Income Tax Expense (Benefit)		(538		)	4,502
	Equity in Earnings of 50% or Less Owned Companies		—			302
	Net Income (Loss)		$	(999	)	$	19,400
	SEI
	Operating Revenues		$	—		$	162,930
	Costs and Expenses:
	Operating		—			159,963
	Administrative and general		—			1,510
	Depreciation and amortization		—			(5		)
			—			161,468
	Operating Income		—			1,462
	Other Income (Expense), Net (including gain on sale of business)		(143		)	(1,131		)
	Income Tax Expense (Benefit)		(50		)	239
	Net Income (Loss)		$	(93	)	$	92
	Era Group
	Operating Revenues		$	22,892		$	61,052
	Costs and Expenses:
	Operating		14,076			39,676
	Administrative and general		2,653			9,677
	Depreciation and amortization		3,875			9,630
			20,604			58,983
	Gains on Asset Dispositions and Impairments, Net		548			1,765
	Operating Income		2,836			3,834
	Other Income (Expense), Net		(1,316		)	(813		)
	Income Tax Expense(1)		10,818			909
	Equity in Earnings (Losses) of 50% or Less Owned Companies		65			(6,419		)
	Net Income (Loss)		$	(9,233	)	$	(4,307	)
	Eliminations
	Operating Revenues		$	—		$	(23,948	)
	Costs and Expenses:
	Operating		—			(23,948		)
	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 three months ended March 31, 2013 in the table included herein (see Note 15).

Restatement_Tables

Restatement (Tables)	3 Months Ended
	Mar. 31, 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):
		March 31, 2013			March 31, 2013
		(As Restated)			(As Previously Reported)
	Balance Sheet (unaudited):
	Other current liabilities	$	119,414		$	109,300
	Total current liabilities	206,868			196,754
	Total liabilities	1,404,178			1,394,064
	Retained earnings	1,037,312			1,047,426
	SEACOR Holdings Inc. stockholders' equity	1,285,171			1,295,285
	Total equity	1,311,309			1,321,423
		For the Three Months Ended
		March 31, 2013			March 31, 2013
		(As Restated)			(As Previously Reported)
	Statement of Income (Loss) (unaudited):
	Loss from Discontinued Operations, Net of Tax	$	(10,325	)	$	(211	)
	Net Loss	(21,361		)	(11,247		)
	Net Loss attributable to SEACOR Holdings Inc.	(20,988		)	(10,874		)
	Net Loss attributable to SEACOR Holdings Inc.:
	Continuing operations	$	(10,763	)	$	(10,763	)
	Discontinued operations	(10,225		)	(111		)
		$	(20,988	)	$	(10,874	)
	Basic Loss Per Common Share of SEACOR Holdings Inc.:
	Continuing operations	$	(0.55	)	$	(0.55	)
	Discontinued operations	(0.51		)	—
		$	(1.06	)	$	(0.55	)
	Diluted Loss Per Common Share of SEACOR Holdings Inc.:
	Continuing operations	$	(0.55	)	$	(0.55	)
	Discontinued operations	(0.51		)	—
		$	(1.06	)	$	(0.55	)
	Statement of Comprehensive Income (Loss) (unaudited):
	Net Loss	$	(21,361	)	$	(11,247	)
	Comprehensive Loss	(24,116		)	(14,002		)
	Comprehensive Loss attributable to SEACOR Holdings Inc.	(23,268		)	(13,154		)

Basis_of_Presentation_and_Acco3

Basis of Presentation and Accounting Policy (Narrative) (Details) (USD $)	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2013	Jun. 30, 2013
					Offshore Marine Services [Member]	Era Group [Member]
Nature of Operations and Accounting Policies [Line Items]	'	'	'	'	'	'
Liability for Uncertain Tax Positions, Current	'	'	'	'	'	$10,100,000
Deferred Revenue	$6,592,000	$6,592,000	$6,354,000	$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 $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012
Nature Of Operations And Accounting Policies [Abstract]	'	'
Balance at beginning of period	$6,592	$9,845
Revenues deferred during the period	0	1,132
Revenues recognized during the period	0	-4,623
Balance at end of period	$6,592	$6,354

Basis_of_Presentation_and_Acco5

Basis of Presentation and Accounting Policy Accumulated Other Comprehensive Income (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Stock Issued During Period, Value, Restricted Stock Award, Gross	($33)	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	-4,321	'	-1,986
Stockholders' Equity Note, Spinoff Transaction	-415,371	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	-3,507	'	'
Other Comprehensive Income (Loss), before Tax	-3,982	4,234	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	1,227	'	'
Income tax expense	-1,227	1,394	'
Other Comprehensive Income (Loss), Net of Tax	-2,755	2,840	'
Accumulated Translation Adjustment [Member]	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	-3,713	'	-1,238
Stockholders' Equity Note, Spinoff Transaction	-55	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	-3,723	'	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	1,303	'	'
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	-592	'	-732
Stockholders' Equity Note, Spinoff Transaction	0	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	216	'	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	-76	'	'
Other Postretirement Benefit Plans, Defined Benefit [Member]	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	-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]	'	'	'
Stock Issued During Period, Value, Restricted Stock Award, Gross	0	'	'
Stockholders' Equity Note, Spinoff Transaction	-107	'	'
Other Comprehensive Income (Loss), Net of Tax	-475	'	'
Non-Controlling Interests In Subsidiaries [Member] | Accumulated Translation Adjustment [Member]	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	-154	'	321
Stockholders' Equity Note, Spinoff Transaction	0	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Noncontrolling Interest	-475	'	'
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
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]	'	'	'
Stock Issued During Period, Value, Restricted Stock Award, Gross	0	'	'
Stockholders' Equity Note, Spinoff Transaction	-55	'	'
Other Comprehensive Income (Loss), Net of Tax	($2,280)	'	'

Fair_Value_Measurements_Financ

Fair Value Measurements (Financial Assets And Liabilities Measured At Fair Value On Recurring Basis) (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Marketable security gains (losses), net include losses	$4,000,000	$2,000,000
Fair Value, Inputs, Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Marketable securities	22,568,000	'
Derivative instruments (included in other receivables)	465,000	'
Short sales of marketable securities	9,610,000	'
Derivative instruments (included in other current liabilities)	770,000	'
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)	6,052,000	'
Construction reserve funds and Title XI reserve funds	0	'
Short sales of marketable securities	0	'
Derivative instruments (included in other current liabilities)	5,478,000	'
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 $)	Mar. 31, 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	$340,106
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)	22,990
Long-term debt, including current portion, Carrying Amount	670,819
Debt Instrument, Fair Value Disclosure	0
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	340,106
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	783,655
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

Fair_Value_Measurements_NonFin

Fair Value Measurements (Non-Financial Assets And Liabilities Measured At Fair Value) (Details) (USD $)	3 Months Ended
	Mar. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Asset Impairment Charges	$3,000,000
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	17,494,000
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

Derivative_Instruments_And_Hed2

Derivative Instruments And Hedging Strategies (Narrative) (Details)	Mar. 31, 2013	Mar. 31, 2013	Mar. 31, 2013	Mar. 31, 2013	Mar. 31, 2013	Mar. 31, 2013	Mar. 31, 2013	Mar. 31, 2013
In Millions, unless otherwise specified	Derivatives Not Designated As Hedging Instruments [Member]	Offshore Marine Services Joint Ventures [Member]	C Lift L L C [Member]	Inland River Joint Venture [Member]	Shipping Services [Member]	Windcat Acquisition [Member]	Windcat Acquisition [Member]	Dynamic Offshore Drilling Ltd [Member]
	USD ($)	Cash Flow Hedging [Member]	USD ($)	Cash Flow Hedging [Member]	Cash Flow Hedging [Member]	USD ($)	EUR (€)	USD ($)
		USD ($)		USD ($)	USD ($)
Derivative [Line Items]	'	'	'	'	'	'	'	'
Fixed interest rate range, minimum	2.25%	'	'	1.53%	'	'	'	'
Fixed interest rate range, maximum	3.00%	'	'	4.16%	'	'	'	'
Fixed interest rate	'	1.48%	3.05%	'	2.79%	'	'	1.30%
Derivative, Notional Amount	$198.80	$17.80	$24	$42.20	$38.90	$15.30	€ 11.90	$108

Derivative_Instruments_And_Hed3

Derivative Instruments And Hedging Strategies (Fair Values Of Derivative Instruments) (Details) (Derivatives Not Designated As Hedging Instruments [Member], USD $)	Mar. 31, 2013
In Thousands, unless otherwise specified
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	$6,517
Derivative Liability	6,248
Foreign Exchange [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	209
Derivative Liability	886
Interest Rate Swap [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	0
Derivative Liability	4,561
Options On Equities And Equity Indices [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	234
Derivative Liability	182
Commodity Swap, Option And Future Contracts, Non-Exchange Traded [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	5,609
Derivative Liability	30
Commodity Contract [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	465
Derivative Liability	$589

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
	Mar. 31, 2013	Mar. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss)	$49,000	($476,000)
Gain (Loss) on Interest Rate Cash Flow Hedge Ineffectiveness	0	-28,000
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	49,000	-504,000
Offshore Marine Services Joint Ventures [Member] | Cash Flow Hedging [Member]	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Derivative, Fixed Interest Rate	1.48%	'
Derivative, Notional Amount	17,800,000	'
Inland River Joint Venture [Member] | Cash Flow Hedging [Member]	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Derivative, Lower Fixed Interest Rate Range	1.53%	'
Derivative, Higher Fixed Interest Rate Range	4.16%	'
Derivative, Notional Amount	$42,200,000	'

Derivative_Instruments_And_Hed5

Derivative Instruments And Hedging Strategies (Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments) (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Derivative [Line Items]	'	'
Derivative gains (losses), net	($2,107,000)	($2,930,000)
Options On Equities And Equity Indices [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	-2,284,000	-1,212,000
Forward Currency Exchange, Option And Future Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	-598,000	583,000
Interest Rate Swap [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	89,000	-209,000
Commodity Contract [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	-744,000	-993,000
Commodity Swap, Option And Future Contracts, Non-Exchange Traded [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	1,430,000	-1,099,000
U.S. Treasury Notes, Rate Locks And Bond Future And Option Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	0	0
Derivatives Not Designated As Hedging Instruments [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Lower Fixed Interest Rate Range	2.25%	'
Derivative, Higher Fixed Interest Rate Range	3.00%	'
Derivative, Notional Amount	198,800,000	'
C Lift L L C [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Notional Amount	24,000,000	'
Derivative, Fixed Interest Rate	3.05%	'
Derivatives Not Designated As Hedging Instruments [Member] | Forward Currency Exchange, Option And Future Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Notional Amount	$13,600,000	'

Business_Acquisitions_Narrativ

Business Acquisitions (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Jun. 25, 2012
Pantagro Acquisition [Member] [Member]	'	'
Business Acquisition [Line Items]	'	'
Business Acquisition, Cost of Acquired Entity, Cash Paid	$0.20	'
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred	0.2	'
Equity Method Investment, Ownership Percentage	'	95.00%
Business Combination, Consideration Transferred	0.4	'
Superior Energy Services, LLC [Member]	'	'
Business Acquisition [Line Items]	'	'
Business Acquisition, Cost of Acquired Entity, Cash Paid	$142.50	'
Superior Energy Services, LLC [Member] | Liftboats [Member]	'	'
Business Acquisition [Line Items]	'	'
Number Of Equipments Delivered	18	'

Business_Acquisitions_Allocati

Business Acquisitions (Allocation Of Purchase Price For Business Acquisitions) (Details) (USD $)	Mar. 31, 2013
In Thousands, unless otherwise specified
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]	'
Property and Equipment	($1,599)
Intangible Assets	1,599
Purchase price	$0	[1]
[1]	Property and Equipment$(1,599)Intangible Assets1,599Purchase price$—

Equipment_Acquisitions_Disposi2

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies (Deferred Gain Activity) (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2011
Movement in Deferred Gain Activity [Roll Forward]	'	'	'	'
Deferred Gains at Beginning of Period	$107,997	$111,514	$117,192	$111,466
Deferred Gain On Sale Of Equipments	'	0	0	'
Amortization Of Deferred Gains Included in Operating Expenses As A Reduction To Rental Expense	'	-2,801	-4,925	'
Amortization Of Deferred Gains Included In Gains On Asset Dispositions And Impairments, Net	700	-716	-801	'
Deferred Gains at End of Period	'	$107,997	$111,514	$111,466

Equipment_Acquisitions_Disposi3

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies (Useful Life) (Details)	3 Months Ended
	Mar. 31, 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
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

Equipment_Acquisitions_Disposi4

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies (Narrative) (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]	'	'	'	'
Purchases of property and equipment	$33,855,000	$65,332,000	'	'
Sales Price Of Equipment	68,400,000	'	'	'
Proceeds from Sale of Property, Plant and Equipment, Excluding Deposits on Future Equipment Sales	61,300,000	'	'	'
Proceeds from disposition of property and equipment	61,369,000	2,883,000	'	'
Proceeds from Issuance of Secured Debt	7,100,000	'	'	'
Gains (Losses) on Sales of Assets	4,300,000	'	'	'
Amortization Of Deferred Gains Included In Gains On Asset Dispositions And Impairments, Net	700,000	'	-716,000	-801,000
Asset Impairment Charges	3,000,000	'	'	'
Offshore Support Vessels [Member]	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'
Number Of Equipments Delivered	2	'	'	'
Number Of Equipments Sold	2	'	'	'
Wind Farm Utility Vessel [Member]	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'
Number Of Equipments Delivered	1	'	'	'
Inland River Liquid Tank Barges [Member]	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'
Number Of Equipments Delivered	1	'	'	'
Mexmar [Member]	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'
Proceeds from disposition of property and equipment	$60,500,000	'	'	'
Mexmar [Member] | Offshore Support Vessels [Member]	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'
Number Of Equipments Delivered	1	'	'	'
Number Of Equipments Sold	2	'	'	'

Investments_At_Equity_And_Adva1

Investments, At Equity, And Advances To 50% Or Less Owned Companies (Narrative) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2013
Schedule Of Equity Method Investments [Line Items]	'
Guarantor Obligations, Maximum Exposure, Undiscounted	$26.60
Allocable Share of Uncalled Capital	2.4
Sea-Cat Crewzer II [Member]	'
Schedule Of Equity Method Investments [Line Items]	'
Partners' Capital Account, Contributions	11.5
Proceeds From Property And Equipment Sales To Fifty Percent Or Less Owned Companies	24.1
Payments to Acquire Machinery and Equipment	23
Secured Debt	1.1
Mexmar [Member]	'
Schedule Of Equity Method Investments [Line Items]	'
Partners' Capital Account, Contributions	5.9
Proceeds From Property And Equipment Sales To Fifty Percent Or Less Owned Companies	36.4
Payments to Acquire Machinery and Equipment	30.4
Secured Debt	6
Loans/notes receivable	6.1
SCFCo Holdings [Member]	'
Schedule Of Equity Method Investments [Line Items]	'
Partners' Capital Account, Contributions	1.4
Temporary Working Capital Advances Provided during the Period	0.5
Outstanding Working Capital Advances At End Of Period	2.8
Bunge Scf Grain [Member]	'
Schedule Of Equity Method Investments [Line Items]	'
Temporary Working Capital Advances Provided during the Period	2.5
Temporary Working Capital Advances Repaid during the Period	0.5
Outstanding Working Capital Advances At End Of Period	7
Corporate Joint Venture [Member]	'
Schedule Of Equity Method Investments [Line Items]	'
Partners' Capital Account, Contributions	$0.50
Offshore Support Vessels [Member]	'
Schedule Of Equity Method Investments [Line Items]	'
Number Of Equipments Delivered	2
Offshore Support Vessels [Member] | Sea-Cat Crewzer II [Member]	'
Schedule Of Equity Method Investments [Line Items]	'
Number Of Equipments Delivered	1
Offshore Support Vessels [Member] | Mexmar [Member]	'
Schedule Of Equity Method Investments [Line Items]	'
Number Of Equipments Delivered	1

Commitments_And_Contingencies_

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

Mar. 31, 2013

Jun. 08, 2011

Jul. 20, 2010

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Mar. 31, 2013

Mar. 31, 2013

Mar. 31, 2013

Mar. 31, 2013

Mar. 31, 2013

Mar. 31, 2013

Mar. 31, 2013

Robins Case [Member]

Wunstell Action [Member]

Darnell Alexander [Member]

Prejean [Member]

Abney Litigation [Member]

HEPACO Litigation [Member]

Inland River Towboats [Member]

Offshore Support Vessels [Member]

Inland River Liquid Tank Barges [Member]

Harbor Tugs [Member]

Other Machinery and Equipment [Member]

Subsequent Event [Member]

Capital Lease Obligations [Member]

claim

plaintiff

claim

claim

claim

equipment

equipment

equipment

equipment

Harbor Tugs [Member]

equipment

Loss Contingencies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total unfunded capital commitments

$151,800,000

'

'

'

'

'

'

$12,700,000

$106,100,000

$15,000,000

$7,400,000

$8,000,000

$49,700,000

$2,600,000

Unrecorded Unconditional Purchase Obligation, Maximum Quantity

'

'

'

'

'

'

'

5

14

7

4

'

'

2

Purchase commitments payable during the period

97,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of claims company did not attempt to dismiss

'

1

'

'

'

'

'

'

'

'

'

'

'

'

Number of plantiffs

'

'

2

'

'

'

'

'

'

'

'

'

'

'

Additional individual civil actions filed

'

'

'

117

4

668

'

'

'

'

'

'

'

'

Loss Contingency, Damages Sought, Value

'

'

'

'

'

'

$20,291,178.92

'

'

'

'

'

'

'

Multiemployer_Pension_Plans_De

Multiemployer Pension Plans (Details) (AMOPP [Member], USD $)	Sep. 30, 2012
In Millions, unless otherwise specified
AMOPP [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Pension and other postretirement benefit plans, withdrawal liability	$45.60

LongTerm_Debt_and_Capital_Leas1

Long-Term Debt and Capital Lease Obligations (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Debt Instrument [Line Items]	'	'	'
Letters of Credit Outstanding, Amount	'	$29,100,000	'
Repayments of Long-term Capital Lease Obligations	'	'	2,700,000
Net borrowings (repayments) on inventory financing arrangements	5,519,000	17,312,000	'
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
7.375% Senior Notes [Member]	'	'	'
Debt Instrument [Line Items]	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	'	7.38%	'

Stock_Repurchases_Details

Stock Repurchases (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012
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
	Mar. 31, 2013	Mar. 31, 2012
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]	'	'
Net Income (Loss) Attributable to Parent	($20,988,000)	$36,488,000
Effect of Dilutive Share Awards:	'	'
Incremental Common Shares Attributable to Share-based Payment Arrangements	0	373,550
Incremental Common Shares Attributable to Conversion of Debt Securities	0	'
Net Income (Loss) Available to Common Stockholders, Diluted	-20,988,000	36,488,000
Weighted Average Number of Shares Outstanding, Basic	19,738,930	20,519,660
Weighted Average Number of Shares Outstanding, Diluted	19,738,930	20,893,210
Earnings Per Share, Basic	($1.06)	$1.78
Earnings Per Share, Diluted	($1.06)	$1.75
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	1,474,897	501,274
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	'
Interest on Convertible Debt, Net of Tax	4,600,000	'
Equity Securities [Member]	'	'
Effect of Dilutive Share Awards:	'	'
Dilutive Securities, Effect on Basic Earnings Per Share	0	0
Convertible Debt Securities [Member]	'	'
Effect of Dilutive Share Awards:	'	'
Dilutive Securities, Effect on Basic Earnings Per Share	$0	'

Share_Based_Compensation_Share

Share Based Compensation (Share Based Compensation Plans) (Details)	3 Months Ended
	Mar. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Director stock awards granted	1,000,000
Employee Stock Purchase Plan shares issued	17,998,000
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, 2011	1,281,821,000
Stock Option, Granted	368,612,000
Stock Option, Exercised	68,543,000
Stock Option, Forfeited	0
Stock Option, Expired	1,576,000
Stock Options, Outstanding as of March 31, 2012	1,580,314,000
Shares available for future grants and ESPP purchases as of March 31, 2012	1,001,595,000
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
	Mar. 31, 2013		Mar. 31, 2012		Dec. 31, 2012
Operating Revenue:	'		'		'
External customers	$267,064,000		$297,849,000		'
Operating Revenues	267,064,000		297,849,000		'
Costs and Expenses [Abstract]	'		'		'
Operating Expenses	200,913,000		208,419,000		'
Administrative and general	35,645,000		34,991,000		'
Depreciation and amortization	33,548,000		29,702,000		'
Total costs and expenses	270,106,000		273,112,000		'
Gains on Asset Dispositions and Impairments Net	2,015,000		3,777,000		'
Operating Income (Loss)	-1,027,000		28,514,000		'
Other Income and Expenses [Abstract]	'		'		'
Derivative gains (losses), net	-2,107,000		-2,958,000		'
Foreign currency gains (losses), net	-4,011,000		1,661,000		'
Other Nonoperating Income (Expense)	3,000		-84,000		'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	-869,000		7,661,000		'
Other Income (Expense) not included in Segment Profit	5,678,000		4,146,000		'
Less Equity Earnings included in Segment Profit	869,000		-7,661,000		'
Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	-12,820,000		22,987,000		'
Capital Expenditures	33,855,000		65,332,000		'
Property, Plant and Equipment, Gross	2,186,892,000		2,212,159,000		2,238,383,000
Accumulated depreciation	785,765,000		694,115,000		763,803,000
Property, Plant and Equipment, Net In Service	1,401,127,000		1,518,044,000		1,474,580,000
Construction in Progress, Gross	113,381,000		138,678,000		110,296,000
Net property and equipment	1,514,508,000		1,656,722,000		1,584,876,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	299,778,000		179,931,000		'
Inventories	31,966,000	[1]	31,965,000		25,787,000
Goodwill	17,978,000		56,702,000		17,978,000
Intangible Assets, Net	15,754,000		22,132,000		15,305,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	277,968,000	[2]	345,465,000	[2]	'
Cash And Near Cash Assets	557,151,000		605,407,000		'
Assets of Disposal Group, Including Discontinued Operation	'		1,008,629,000		'
Discontinued operations	384,000		'		108,153,000
Total assets	2,715,487,000		3,906,953,000		3,700,794,000
Offshore Marine Services [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	123,992,000		120,951,000		'
Operating Revenues	123,992,000		120,951,000		'
Costs and Expenses [Abstract]	'		'		'
Operating Expenses	90,031,000		75,340,000		'
Administrative and general	14,827,000		11,856,000		'
Depreciation and amortization	16,287,000		12,882,000		'
Total costs and expenses	121,145,000		100,078,000		'
Gains on Asset Dispositions and Impairments Net	2,339,000		1,845,000		'
Operating Income (Loss)	5,210,000		22,853,000		'
Other Income and Expenses [Abstract]	'		'		'
Derivative gains (losses), net	150,000		0		'
Foreign currency gains (losses), net	-3,264,000		1,123,000		'
Other Nonoperating Income (Expense)	0		0		'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,313,000		1,829,000		'
Segment Profit (Loss)	3,409,000		25,805,000		'
Capital Expenditures	19,920,000		42,778,000		'
Property, Plant and Equipment, Gross	1,110,480,000		1,120,414,000		'
Accumulated depreciation	428,766,000		386,583,000		'
Property, Plant and Equipment, Net In Service	681,714,000		733,831,000		'
Construction in Progress, Gross	61,447,000		92,322,000		'
Net property and equipment	743,161,000		826,153,000		'
Investments, at Equity, and Advances to 50% or Less Owned Companies	85,311,000		68,645,000		'
Inventories	6,497,000		6,261,000		'
Goodwill	13,367,000		13,367,000		'
Intangible Assets, Net	5,105,000		5,500,000		'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	136,661,000		140,019,000		'
Total segment assets	990,102,000		1,059,945,000		'
Inland River Services [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	49,423,000		53,490,000		'
Operating Revenues	49,423,000		53,490,000		'
Costs and Expenses [Abstract]	'		'		'
Operating Expenses	36,389,000		35,183,000		'
Administrative and general	4,024,000		3,982,000		'
Depreciation and amortization	7,084,000		7,007,000		'
Total costs and expenses	47,497,000		46,172,000		'
Gains on Asset Dispositions and Impairments Net	697,000		1,927,000		'
Operating Income (Loss)	3,277,000		9,245,000		'
Other Income and Expenses [Abstract]	'		'		'
Derivative gains (losses), net	0		0		'
Foreign currency gains (losses), net	-137,000		-22,000		'
Other Nonoperating Income (Expense)	0		0		'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	-2,387,000		250,000		'
Segment Profit (Loss)	753,000		9,473,000		'
Capital Expenditures	5,727,000		4,884,000		'
Property, Plant and Equipment, Gross	493,140,000		474,013,000		'
Accumulated depreciation	133,827,000		109,715,000		'
Property, Plant and Equipment, Net In Service	359,313,000		364,298,000		'
Construction in Progress, Gross	15,335,000		11,670,000		'
Net property and equipment	374,648,000		375,968,000		'
Investments, at Equity, and Advances to 50% or Less Owned Companies	55,105,000		50,758,000		'
Inventories	2,297,000		2,681,000		'
Goodwill	2,759,000		4,345,000		'
Intangible Assets, Net	8,824,000		8,755,000		'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	37,787,000		61,675,000		'
Total segment assets	481,420,000		504,182,000		'
Shipping Services [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	46,476,000		45,733,000		'
Operating Revenues	46,476,000		45,733,000		'
Costs and Expenses [Abstract]	'		'		'
Operating Expenses	26,614,000		27,572,000		'
Administrative and general	5,177,000		4,867,000		'
Depreciation and amortization	7,797,000		7,617,000		'
Total costs and expenses	39,588,000		40,056,000		'
Gains on Asset Dispositions and Impairments Net	-3,069,000		0		'
Operating Income (Loss)	3,819,000		5,677,000		'
Other Income and Expenses [Abstract]	'		'		'
Derivative gains (losses), net	0		0		'
Foreign currency gains (losses), net	-7,000		13,000		'
Other Nonoperating Income (Expense)	14,000		30,000		'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	-1,505,000		-217,000		'
Segment Profit (Loss)	2,321,000		5,503,000		'
Capital Expenditures	6,814,000		10,543,000		'
Property, Plant and Equipment, Gross	506,279,000		525,497,000		'
Accumulated depreciation	206,603,000		183,461,000		'
Property, Plant and Equipment, Net In Service	299,676,000		342,036,000		'
Construction in Progress, Gross	33,444,000		27,419,000		'
Net property and equipment	333,120,000		369,455,000		'
Investments, at Equity, and Advances to 50% or Less Owned Companies	65,941,000		11,989,000		'
Inventories	1,284,000		1,476,000		'
Goodwill	1,852,000		1,852,000		'
Intangible Assets, Net	1,272,000		1,811,000		'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	18,316,000		15,564,000		'
Total segment assets	421,785,000		402,147,000		'
Ethanol and Industrial Alcohol [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	32,849,000		39,619,000		'
Operating Revenues	32,849,000		39,619,000		'
Costs and Expenses [Abstract]	'		'		'
Operating Expenses	34,045,000		37,405,000		'
Administrative and general	661,000		425,000		'
Depreciation and amortization	1,489,000		1,052,000		'
Total costs and expenses	36,195,000		38,882,000		'
Gains on Asset Dispositions and Impairments Net	0		0		'
Operating Income (Loss)	-3,346,000		737,000		'
Other Income and Expenses [Abstract]	'		'		'
Derivative gains (losses), net	39,000		-485,000		'
Foreign currency gains (losses), net	0		0		'
Other Nonoperating Income (Expense)	0		0		'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0		6,154,000		'
Segment Profit (Loss)	-3,307,000		6,406,000		'
Capital Expenditures	0		0		'
Property, Plant and Equipment, Gross	43,788,000		43,693,000		'
Accumulated depreciation	7,146,000		1,038,000		'
Property, Plant and Equipment, Net In Service	36,642,000		42,655,000		'
Construction in Progress, Gross	0		0		'
Net property and equipment	36,642,000		42,655,000		'
Investments, at Equity, and Advances to 50% or Less Owned Companies	0		0		'
Inventories	19,868,000		15,178,000		'
Goodwill	0		0		'
Intangible Assets, Net	72,000		157,000		'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	5,947,000		6,726,000		'
Total segment assets	62,529,000		64,716,000		'
Sales Revenue, Goods, Net	32,100,000		38,900,000		'
Cost of Goods Sold	34,400,000		38,000,000		'
Inventory, Raw Materials	3,000,000		2,800,000		'
Inventory, Work in Process	2,400,000		2,400,000		'
Other Segments [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	14,324,000		38,056,000		'
Operating Revenues	14,324,000		38,056,000		'
Other [Member]	'		'		'
Costs and Expenses [Abstract]	'		'		'
Operating Expenses	14,488,000		33,077,000		'
Administrative and general	1,656,000		4,798,000		'
Depreciation and amortization	99,000		689,000		'
Total costs and expenses	16,243,000		38,564,000		'
Gains on Asset Dispositions and Impairments Net	1,907,000		5,000		'
Operating Income (Loss)	-12,000		-451,000		'
Other Income and Expenses [Abstract]	'		'		'
Derivative gains (losses), net	842,000		-1,417,000		'
Foreign currency gains (losses), net	-167,000		99,000		'
Other Nonoperating Income (Expense)	54,000		0		'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,710,000		-355,000		'
Segment Profit (Loss)	2,427,000		-2,124,000		'
Capital Expenditures	357,000		6,106,000		'
Property, Plant and Equipment, Gross	4,032,000		22,316,000		'
Accumulated depreciation	467,000		3,271,000		'
Property, Plant and Equipment, Net In Service	3,565,000		19,045,000		'
Construction in Progress, Gross	2,063,000		2,676,000		'
Net property and equipment	5,628,000		21,721,000		'
Investments, at Equity, and Advances to 50% or Less Owned Companies	93,421,000		48,539,000		'
Inventories	2,020,000		6,369,000		'
Goodwill	0		37,138,000		'
Intangible Assets, Net	481,000		5,909,000		'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	47,877,000		104,243,000		'
Total segment assets	149,427,000		223,919,000		'
Corporate And Eliminations [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	0		0		'
Operating Revenues	0		0		'
Costs and Expenses [Abstract]	'		'		'
Operating Expenses	-654,000		-158,000		'
Administrative and general	9,300,000		9,063,000		'
Depreciation and amortization	792,000		455,000		'
Total costs and expenses	9,438,000		9,360,000		'
Gains on Asset Dispositions and Impairments Net	141,000		0		'
Operating Income (Loss)	-9,975,000		-9,547,000		'
Other Income and Expenses [Abstract]	'		'		'
Derivative gains (losses), net	-3,138,000		-1,056,000		'
Foreign currency gains (losses), net	-436,000		448,000		'
Other Nonoperating Income (Expense)	-65,000		-114,000		'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0		0		'
Capital Expenditures	1,037,000		1,021,000		'
Property, Plant and Equipment, Gross	29,173,000		26,226,000		'
Accumulated depreciation	8,956,000		10,047,000		'
Property, Plant and Equipment, Net In Service	20,217,000		16,179,000		'
Construction in Progress, Gross	1,092,000		4,591,000		'
Net property and equipment	21,309,000		20,770,000		'
Investments, at Equity, and Advances to 50% or Less Owned Companies	0		0		'
Inventories	0		0		'
Goodwill	0		0		'
Intangible Assets, Net	0		0		'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	31,380,000		17,238,000		'
Operating Segments [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	267,064,000		297,849,000		'
Operating Revenues	267,064,000		297,849,000		'
Operating Segments [Member] | Offshore Marine Services [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	124,016,000		121,086,000		'
Operating Revenues	124,016,000		121,086,000		'
Operating Segments [Member] | Inland River Services [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	50,077,000		53,490,000		'
Operating Revenues	50,077,000		53,490,000		'
Operating Segments [Member] | Shipping Services [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	46,476,000		45,733,000		'
Operating Revenues	46,476,000		45,733,000		'
Operating Segments [Member] | Ethanol and Industrial Alcohol [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	32,849,000		39,619,000		'
Operating Revenues	32,849,000		39,619,000		'
Operating Segments [Member] | Other Segments [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	14,324,000		38,108,000		'
Operating Revenues	14,324,000		38,108,000		'
Operating Segments [Member] | Corporate And Eliminations [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	-678,000		-187,000		'
Operating Revenues	-678,000		-187,000		'
Intersegment Eliminations [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	0		0		'
Operating Revenues	0		0		'
Intersegment Eliminations [Member] | Offshore Marine Services [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	-24,000		-135,000		'
Operating Revenues	-24,000		-135,000		'
Intersegment Eliminations [Member] | Inland River Services [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	-654,000		0		'
Operating Revenues	-654,000		0		'
Intersegment Eliminations [Member] | Shipping Services [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	0		0		'
Operating Revenues	0		0		'
Intersegment Eliminations [Member] | Ethanol and Industrial Alcohol [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	0		0		'
Operating Revenues	0		0		'
Intersegment Eliminations [Member] | Other Segments [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	0		-52,000		'
Operating Revenues	0		-52,000		'
Intersegment Eliminations [Member] | Corporate And Eliminations [Member]	'		'		'
Operating Revenue:	'		'		'
External customers	678,000		187,000		'
Operating Revenues	$678,000		$187,000		'
[1]	Inventories includes raw materials of $3.0 million and work in process of $2.4 million.
[2]	Cash and near cash assets includes cash, cash equivalents, restricted cash, marketable securities, construction reserve funds and Title XI reserve funds.

Discontinued_Operations_Detail

Discontinued Operations (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012
Operating Revenues	$267,064	$297,849
Operating Expenses	200,913	208,419
Administrative and general	35,645	34,991
Depreciation and amortization	33,548	29,702
Total costs and expenses	270,106	273,112
Operating Income (Loss)	-1,027	28,514
Nonoperating Income (Expense)	-11,793	-5,527
Income Tax Expense (Benefit)	-2,653	9,460
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	-869	7,661
Net Income	-21,361	36,373
SES Business [Member]	'	'
Operating Revenues	0	22,387
Operating Expenses	0	18,234
Administrative and general	0	4,020
Depreciation and amortization	0	1,428
Total costs and expenses	0	23,682
Losses (Gains) on Sales of Assets and Asset Impairment Charges	0	71
Operating Income (Loss)	0	-1,366
Nonoperating Income (Expense)	-1,537	24,966
Income Tax Expense (Benefit)	-538	4,502
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	302
Net Income	-999	19,400
SEI [Member]	'	'
Operating Revenues	0	162,930
Operating Expenses	0	159,963
Administrative and general	0	1,510
Depreciation and amortization	0	-5
Total costs and expenses	0	161,468
Operating Income (Loss)	0	1,462
Nonoperating Income (Expense)	-143	-1,131
Income Tax Expense (Benefit)	-50	239
Net Income	-93	92
Era Group [Member]	'	'
Operating Revenues	22,892	61,052
Operating Expenses	14,076	39,676
Administrative and general	2,653	9,677
Depreciation and amortization	3,875	9,630
Total costs and expenses	20,604	58,983
Losses (Gains) on Sales of Assets and Asset Impairment Charges	-548	-1,765
Operating Income (Loss)	2,836	3,834
Nonoperating Income (Expense)	-1,316	-813
Income Tax Expense (Benefit)	10,818	909
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	65	-6,419
Net Income	-9,233	-4,307
Consolidation, Eliminations [Member]	'	'
Operating Revenues	0	-23,948
Operating Expenses	0	-23,948
Operating Income (Loss)	$0	$0

Restatement_Details

Restatement (Details) (USD $)	3 Months Ended			3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Mar. 31, 2013	Mar. 31, 2013	Mar. 31, 2012	Jun. 30, 2013
				Scenario, Previously Reported [Member]	Era Group [Member]	Era Group [Member]	Era Group [Member]
Liability for Uncertain Tax Positions, Current	'	'	'	'	'	'	$10,100,000
Other current liabilities	119,414,000	'	93,093,000	109,300,000	'	'	'
Liabilities, Current	206,868,000	'	265,641,000	196,754,000	'	'	'
Liabilities	1,404,178,000	'	1,958,119,000	1,394,064,000	'	'	'
Retained earnings	1,037,312,000	'	1,473,509,000	1,047,426,000	'	'	'
Stockholders' Equity Attributable to Parent	1,285,171,000	'	1,713,654,000	1,295,285,000	'	'	'
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,311,309,000	'	1,742,675,000	1,321,423,000	'	'	'
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	-10,325,000	15,185,000	'	-211,000	'	'	'
Net Income	-21,361,000	36,373,000	'	-11,247,000	-9,233,000	-4,307,000	'
Net Income attributable to SEACOR Holdings Inc.	-20,988,000	36,488,000	'	-10,874,000	'	'	'
Continuing operations	-10,763,000	21,303,000	'	-10,763,000	'	'	'
Discontinued operations, net of tax	-10,225,000	15,185,000	'	-111,000	'	'	'
Continuing operations	($0.55)	$1.04	'	($0.55)	'	'	'
Discontinued operations	($0.51)	$0.74	'	$0	'	'	'
Earnings Per Share, Basic	($1.06)	$1.78	'	($0.55)	'	'	'
Continuing operations	($0.55)	$1.02	'	($0.55)	'	'	'
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	($0.51)	$0.73	'	$0	'	'	'
Earnings Per Share, Diluted	($1.06)	$1.75	'	($0.55)	'	'	'
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	-24,116,000	39,213,000	'	-14,002,000	'	'	'
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	($23,268,000)	$39,077,000	'	($13,154,000)	'	'	'