Seacor (CKH) 10-Q/A 7 Mar 14 2013 Q3 Quarterly report (amended) Financial data

Document_And_Entity_Informatio

Document And Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 25, 2013
Document Information [Line Items]	'	'
Entity Registrant Name	'SEACOR HOLDINGS INC /NEW/	'
Entity Central Index Key	'0000859598	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	20,331,865
Entity Well-known Seasoned Issuer	'Yes	'
Entity Voluntary Filers	'No	'
Entity Current Reporting Status	'Yes	'

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current Assets:	'	'
Cash and cash equivalents	$332,767	$248,204
Restricted cash	20,893	28,285
Marketable securities	25,660	21,668
Receivables:	'	'
Trade, net of allowance for doubtful accounts	211,853	224,944
Other Receivables	39,774	45,334
Inventories	25,442	25,787
Deferred income taxes	3,530	3,530
Prepaid expenses and other	10,746	12,719
Discontinued operations	0	108,153
Total current assets	670,665	718,624
Property and Equipment:	'	'
Property, Plant and Equipment, Gross	2,208,315	2,238,383
Accumulated depreciation	835,604	763,803
Property, Plant and Equipment, Net In Service	1,372,711	1,474,580
Construction in Progress, Gross	129,481	110,296
Net property and equipment	1,502,192	1,584,876
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	365,891	272,535
Construction Reserve Funds & Title XI Reserve Funds	229,021	195,629
Goodwill	17,978	17,978
Intangible Assets, Net	13,583	15,305
Other Assets	52,394	55,123
Discontinued Operations	0	840,724
Total assets	2,851,724	3,700,794
Current Liabilities:	'	'
Current portion of long-term debt	26,973	21,920
Current portion of capital lease obligations	11	2,900
Accounts payable and accrued expenses	73,063	107,892
Other current liabilities	124,777	93,093
Discontinued operations	0	39,836
Total current liabilities	224,824	265,641
Long-Term Debt	675,206	655,309
Capital Lease Obligations	22	59
Deferred Income Taxes	437,436	426,027
Deferred Gains and Other Liabilities	133,503	120,342
Discontinued Operations	0	490,741
Total liabilities	1,470,991	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; 37,168,978 and 36,740,324 shares issued in 2012 and 2011, respectively	372	367
Additional paid-in capital	1,358,273	1,330,324
Retained earnings	1,086,874	1,473,509
Treasury Stock, Value	1,088,219	1,088,560
Accumulated Other Comprehensive Income (Loss), Net of Tax	-1,809	-1,986
Stockholders' equity attributable to parent, total	1,355,491	1,713,654
Noncontrolling interests in subsidiaries	25,242	29,021
Total equity	1,380,733	1,742,675
Liabilities and stockholders' equity, total	$2,851,724	$3,700,794

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Trade receivables, allowance for doubtful accounts	$920	$1,201
Common Stock, Par or Stated Value Per Share	$0.01	$0.01
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	37,168,978	36,740,324
Treasury stock, shares	16,837,113	16,852,391
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Condensed_Consolidated_Stateme

Condensed Consolidated Statements Of Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement [Abstract]	'	'	'	'
Operating Revenues	$336,784	$338,855	$919,411	$945,929
Costs and Expenses [Abstract]	'	'	'	'
Operating	239,540	254,005	680,566	706,969
Administrative and general	31,463	39,509	101,826	110,801
Depreciation and amortization	33,503	34,347	100,834	97,269
Total costs and expenses	304,506	327,861	883,226	915,039
Gain (Loss) on Sale of Assets and Asset Impairment Charges	19,230	9,064	33,550	16,183
Operating Income (Loss)	51,508	20,058	69,735	47,073
Other Income (Expense):	'	'	'	'
Interest income	4,280	3,890	10,665	13,925
Interest expense	10,520	10,076	31,282	30,075
Debt extinguishment losses, net	0	0	0	-160
Marketable security gains, net	-1,149	-1,730	9,403	13,224
Derivative losses, net	-303	-2,030	-3,235	-2,434
Foreign currency gains, net	2,230	1,028	-2,697	1,665
Other, net	477	7,098	675	7,457
Total Other Nonoperating Income (Expense)	-4,985	-1,820	-16,471	3,602
Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	46,523	18,238	53,264	50,675
Income Tax Expense (Benefit)	15,984	7,702	21,306	20,412
Income from Continuing Operations Before Equity in Earnings of 50% or Less Owned Companies	30,539	10,536	31,958	30,263
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	230	-1,297	7,071	6,659
Income from Continuing Operations	30,769	9,239	39,029	36,922
Income (Loss) from Discontinued Operations, Net of Tax	0	6,265	-10,325	26,254
Net Income	30,769	15,504	28,704	63,176
Net Income (Loss) Attributable to Noncontrolling Interest	478	-598	130	-663
Net Income attributable to SEACOR Holdings Inc.	30,291	16,102	28,574	63,839
Net Income (Loss) attributable to SEACOR Holdings Inc.:	'	'	'	'
Continuing operations	30,291	9,837	38,799	37,585
Discontinued operations, net of tax	0	6,265	-10,225	26,254
Net Income attributable to SEACOR Holdings Inc.	$30,291	$16,102	$28,574	$63,839
Basic Earnings Per Common Share of SEACOR Holdings Inc.	'	'	'	'
Continuing operations	$1.52	$0.48	$1.96	$1.83
Discontinued operations	$0	$0.31	($0.52)	$1.28
Earnings Per Share, Basic	$1.52	$0.79	$1.44	$3.11
Diluted Earnings Per Common Share of SEACOR Holdings Inc.	'	'	'	'
Continuing operations	$1.36	$0.47	$1.92	$1.80
Discontinued operations	$0	$0.31	($0.51)	$1.26
Earnings Per Share, Diluted	$1.36	$0.78	$1.41	$3.06
Weighted Average Common Shares Outstanding:	'	'	'	'
Basic	19,964,695	20,432,997	19,843,778	20,512,118
Weighted Average Number of Shares Outstanding, Diluted	24,601,584	20,740,456	20,198,449	20,838,468

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements Of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net Income	$30,769	$15,504	$28,704	$63,176
Other Comprehensive Income (Loss):	'	'	'	'
Reclassification of net foreign currency translation losses to foreign currency gains, net	4,050	2,123	-488	3,908
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	0	0	0	758
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	192	-619	'	'
Reclassification of net derivative losses on cash flow hedges to interest expense or equity in earnings of 50% or less owned companies	0	1,330	0	1,330
Other	0	0	0	42
Other Comprehensive Income (Loss), before Tax	4,177	3,656	337	7,085
Income tax expense	1,311	1,200	125	2,345
Other Comprehensive Income (Loss), Net of Tax	2,866	2,456	212	4,740
Comprehensive Income	33,635	17,960	28,916	67,916
Comprehensive Income attributable to Noncontrolling Interests in Subsidiaries	910	-369	110	-277
Comprehensive Income attributable to SEACOR Holdings Inc.	32,725	18,329	28,806	68,193
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	-65	167	253	386
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	$655	$0	$1,951

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]
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	1,770	0	0	0	1,770	0	0
Exercise of stock options	15,449	3	15,446	0	0	0	0
Director stock awards	-168	0	-168	0	0	0	0
Restricted stock and restricted stock units	113	2	-24	0	135	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	11,426	0	-11,426	0	0	0	0
Stock Issued During Period, Value, Restricted Stock Award, Forfeitures	0	0	1,564	0	-1,564	0	0
Issuance of noncontrolling interests	40	0	0	0	0	0	40
Dividends paid to noncontrolling interests	-3,822	0	0	0	0	0	-3,822
Comprehensive income:	'	'	'	'	'	'	'
Net Income attributable to SEACOR Holdings Inc.	28,574	0	0	'	0	0	'
Net Income (Loss) Attributable to Noncontrolling Interest	130	'	'	'	'	'	130
Net income	28,704	'	'	'	'	'	'
Other comprehensive income	212	0	0	0	0	232	-20
Balance at Sep. 30, 2013	$1,380,733	$372	$1,358,273	$1,086,874	($1,088,219)	($1,809)	$25,242

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements Of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Statement of Cash Flows [Abstract]	'	'
Net Cash Provided by Operating Activities of Continuing Operations	$134,698	$98,633
Cash Flows from Investing Activities of Continuing Operations:	'	'
Purchases of property and equipment	146,483	165,044
Proceeds from disposition of property and equipment	205,735	14,715
Investments in and advances to 50% or less owned companies	91,492	34,507
Return of investments and advances from 50% or less owned companies	10,642	77,981
Net advances on revolving credit line to 50% or less owned companies	0	300
Principal payments on third party notes receivable, net	-63	17,751
Net increase in restricted cash	-7,392	170,501
Net (increase) decrease in construction reserve funds and title XI reserve funds	33,392	-80,042
Repayments on leases, net	2,667	2,586
Businesses acquisitions, net of cash acquired	10,540	148,088
Net cash used in investing activities of continuing operations	-55,534	-325,365
Cash Flows from Financing Activities of Continuing Operations:	'	'
Repayments of Debt and Capital Lease Obligations	13,129	67,178
Net borrowings (repayments) on inventory financing arrangements	-4,183	13,368
Proceeds from issuance of long term debt, net of offering costs	10	115,134
Common stock acquired for treasury	0	28,726
Cash Received (Paid) For Share Settlements from Spinoff Transactions	-357	0
Proceeds and tax benefits from share award plans	17,195	8,400
Cash received from (dividends paid to) noncontrolling interests, net	-3,782	-1,895
Net cash provided by (used in) financing activities of continuing operations	4,120	12,367
Effect of Exchange Rate Changes on Cash and Cash Equivalents	-643	1,944
Net Increase (Decrease) in Cash and Cash Equivalents from Continuing Operations	82,641	-212,421
Cash Flows from Discontinued Operations:	'	'
Operating Activities	24,298	99,629
Investing Activities	-8,502	-7,219
Financing Activities	-14,017	-64,090
Effects of Exchange Rate Changes on Cash and Cash Equivalents	143	687
Net Increase in Cash and Cash Equivalents from Discontinued Operations	1,922	29,007
Net Increase (Decrease) in Cash and Cash Equivalents	84,563	-183,414
Cash and Cash Equivalents, Beginning of Period	248,204	381,482
Cash and Cash Equivalents, End of Period	$332,767	$198,068

Basis_of_Presentation_and_Acco

Basis of Presentation and Accounting Policy	9 Months Ended
	Sep. 30, 2013
Nature Of Operations And Accounting Policies [Abstract]	'
Basis of Presentation and Accounting Policy	'
	BASIS OF PRESENTATION AND ACCOUNTING POLICY
	The condensed consolidated financial information for the three and nine months ended September 30, 2013 and 2012 has been prepared by the Company and has not been audited by its independent registered public accounting firm. The condensed consolidated financial statements include the accounts of SEACOR Holdings Inc. and its consolidated subsidiaries. In the opinion of management, all adjustments (consisting of normal recurring adjustments) have been made to fairly present the Company’s financial position as of September 30, 2013, its results of operations for the three and nine months ended September 30, 2013 and 2012, its comprehensive income for the three and nine months ended September 30, 2013 and 2012, its changes in equity for the nine months ended September 30, 2013, and its cash flows for the nine months ended September 30, 2013 and 2012. Results of operations for the interim periods presented are not necessarily indicative of operating results for the full year or any future periods.
	Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States have been condensed or omitted. These condensed consolidated financial statements should be read in conjunction with the financial statements and related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.
	Unless the context otherwise indicates, any reference in this Quarterly Report on Form 10-Q to the “Company” refers to SEACOR Holdings Inc. and its consolidated subsidiaries and any reference in this Quarterly Report on Form 10-Q to “SEACOR” refers to SEACOR Holdings Inc.
	Discontinued Operations. On January 31, 2013, the Company completed the spin-off ("Spin-off") of Era Group Inc. (“Era Group”), the company that operated SEACOR's Aviation Services business segment, by means of a dividend to SEACOR's stockholders of all the issued and outstanding common stock of Era Group. Era Group filed a Registration Statement on Form 10 with the Securities and Exchange Commission, describing the Spin-off, that was declared effective on January 14, 2013. Era Group is now an independent company whose common stock is listed on the New York Stock Exchange under the symbol "ERA." Discontinued operations includes the historical financial position, results of operations and cash flows of Era Group as well as the operations previously reported as discontinued in the Company's Annual Report on Form 10-K for the year ended December 31, 2012 (see Note 14).
	Revenue Recognition. The Company recognizes revenue when it is realized or realizable and earned. Revenue is realized or realizable and earned when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price to the buyer is fixed or determinable, and collectability is reasonably assured. Revenue that does not meet these criteria is deferred until the criteria are met. Deferred revenues, included in other current liabilities, for the nine months ended September 30 were as follows (in thousands):
		2013				2012
	Balance at beginning of period	$	6,592			$	9,845
	Revenues deferred during the period	—				2,827
	Revenues recognized during the period	—				(7,007		)
	Balance at end of period	$	6,592			$	5,665
	As of September 30, 2013, deferred revenues of $6.6 million were related to the time charter of several offshore support vessels scheduled to be paid through the conveyance of an overriding royalty interest (the "Conveyance") in developmental oil and gas producing properties operated by a customer in the U.S. Gulf of Mexico. Payments under the Conveyance, and the timing of such payments, are contingent upon production and energy sale prices. On August 17, 2012, the customer filed a voluntary petition for Chapter 11 bankruptcy. The Company is vigorously defending its interest in connection with the bankruptcy filing; however, payments received under the Conveyance subsequent to August 17, 2012 are subject to bankruptcy court approval. The Company will continue to recognize revenues as cash is received and approved by the bankruptcy court or earlier should future collection become reasonably assured. All costs and expenses related to these charters were recognized as incurred.
	Accumulated Other Comprehensive 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)		(468		)		825			—			357			(20		)	—			$	337
	Income tax (expense) benefit		164				(289		)	—			(125		)	—			—			(125		)
	Nine months ended September 30, 2013		$	(1,597	)		$	(196	)	$	(16	)	$	(1,809	)	$	301		$	(10	)	$	212
	Reclassifications. Certain reclassifications of prior period information have been made to conform to the presentation of the current period information. These reclassifications had no effect on net income as previously reported.
	Restatement of Interim Financial Results. In late February 2014, in connection with the Company’s year-end accounting review and preparation of its year-end financial statements, an error was discovered in the accounting for taxes related to the Spin-off of Era Group. The restatement of the Company's unaudited condensed consolidated financial statements in this Amendment No. 1 to the Original Filing is solely related to this error in accounting for taxes, the principal effect of which is an increase in the net loss from discontinued operations for the nine months ended September 30, 2013 of $10.1 million (see Note 15).

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	FAIR VALUE MEASUREMENTS
	The fair value of an asset or liability is the price that would be received to sell an asset or transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company utilizes a fair value hierarchy that maximizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value and defines three levels of inputs that may be used to measure fair value. Level 1 inputs are quoted prices in active markets for identical assets or liabilities. Level 2 inputs are observable inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly, including quoted prices for similar assets or liabilities in active markets, quoted prices in markets that are not active, inputs other than quoted prices that are observable for the asset or liability, or inputs derived from observable market data. Level 3 inputs are unobservable inputs that are supported by little or no market activity and are significant to the fair value of the assets or liabilities.
	The Company’s financial assets and liabilities as of September 30, 2013 that are measured at fair value on a recurring basis were as follows (in thousands):
		Level 1			Level 2			Level 3
	ASSETS
	Marketable securities(1)	$	25,660		$	—		$	—
	Derivative instruments (included in other receivables)	177			5,238			—
	Construction reserve funds and Title XI reserve funds	229,021			—			—
	LIABILITIES
	Short sale of marketable securities (included in other current liabilities)	8,837			—			—
	Derivative instruments (included in other current liabilities)	384			3,299			—
	______________________
	-1	Marketable security gains (losses), net include unrealized losses of $1.2 million and unrealized losses of $0.4 million for the three months ended September 30, 2013 and 2012, respectively, related to marketable security positions held by the Company as of September 30, 2013. Marketable security gains (losses), net include unrealized gains of $9.4 million and unrealized losses of $0.4 million for the nine months ended September 30, 2013 and 2012, respectively, related to marketable security positions held by the Company as of September 30, 2013.
	The estimated fair values of the Company’s other financial assets and liabilities as of September 30, 2013 were as follows (in thousands):
					Estimated Fair Value
		Carrying			Level 1			Level 2			Level 3
		Amount
	ASSETS
	Cash, cash equivalents and restricted cash	$	353,660		$	353,660		$	—		$	—
	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	26,462			see below
	assets)
	LIABILITIES
	Long-term debt, including current portion(1)	702,179			—			838,218			—
	______________________
	-1	The estimated fair value includes the conversion option on the Company's 2.5% Convertible Notes.
	The carrying value of cash, cash equivalents and restricted cash approximates fair value. The fair value of the Company’s long-term debt was estimated based upon quoted market prices or by using discounted cash flow analyses based on estimated current rates for similar types of arrangements. It was not practicable to estimate the fair value of the Company’s investments, at cost, in 50% or less owned companies because of the lack of quoted market prices and the inability to estimate fair value without incurring excessive costs. It was not practicable to estimate the fair value of the Company’s notes receivable from other business ventures as the overall returns are uncertain due to certain provisions for additional payments contingent upon future events. Considerable judgment was required in developing certain of the estimates of fair value and, accordingly, the estimates presented herein are not necessarily indicative of the amounts that the Company could realize in a current market exchange.
	The Company’s non-financial assets and liabilities that were measured at fair value during the nine months ended September 30, 2013 were as follows (in thousands):
			Level 1			Level 2			Level 3
	ASSETS
	Long-lived assets under construction(1)		$	17,494		$	—		$	—
	Investment in C-Lift LLC(2)		—			13,290			—
	Contribution of non-cash consideration to Dorian LPG Ltd. (3)		—			14,989			—
	______________________
	-1	During the nine months ended September 30, 2013, the Company recognized impairment charges of $3.0 million related to two of Shipping Services' harbor tugs while under construction, which were sold and leased back upon their completion (see Note 5).
	-2	During the nine months ended September 30, 2013, the Company marked its equity investment in C-Lift LLC ("C-Lift") to fair value following its acquisition of a controlling interest (see Note 4). The investment's fair value was determined based on the Company's purchase price of the acquired interest.
	-3	During the nine months ended September 30, 2013, the Company marked to fair value the non-cash consideration contributed to Dorian LPG Ltd. ("Dorian") in exchange for an equity investment (see Note 6). The fair value was determined based on the value of the equity investment the Company received.

Derivative_Instruments_And_Hed

Derivative Instruments And Hedging Strategies	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments And Hedging Strategies	'
	DERIVATIVE INSTRUMENTS AND HEDGING STRATEGIES
	Derivative instruments are classified as either assets or liabilities based on their individual fair values. Derivative assets and liabilities are included in other receivables and other current liabilities, respectively, in the accompanying condensed consolidated balance sheets. The fair values of the Company’s derivative instruments as of September 30, 2013 were as follows (in thousands):
		Derivative			Derivative
		Asset			Liability
	Options on equities and equity indices	$	269		$	—
	Forward currency exchange, option and future contracts	197			215
	Interest rate swap agreements	—			3,071
	Commodity swap, option and future contracts:
	Exchange traded	71			383
	Non-exchange traded	4,878			14
		$	5,415		$	3,683
	Cash Flow Hedges. As of September 30, 2013, the Company had no interest rate swap agreements designated as cash flow hedges. As of September 30, 2013, one of the Company’s Offshore Marine Services 50% or less owned companies had an interest rate swap agreement maturing in 2015 that has been designated as a cash flow hedge. This instrument calls for this company to pay a fixed interest rate of 1.48% on the amortized notional value of $17.1 million and receive a variable interest rate based on LIBOR on the amortized notional value. As of September 30, 2013, one of the Company’s Inland River Services 50% or less owned companies had four interest rate swap agreements with maturities ranging from 2013 through 2015 that have been designated as cash flow hedges. These instruments call for this company to pay fixed rates of interest ranging from 1.53% to 4.16% on the aggregate amortized notional value of $35.4 million and receive a variable interest rate based on LIBOR on the aggregate amortized notional value. As of September 30, 2013, one of the Company’s Shipping Services 50% or less owned companies had an interest rate swap agreement maturing in 2017 that has been designated as a cash flow hedge. The instrument calls for this company to pay a fixed interest rate of 2.79% on the amortized notional value of $37.8 million and received a variable interest rate based on LIBOR on the amortized notional value. As of September 30, 2013, another of the Company's Shipping Services 50% or less owned companies had five interest rate swap agreements with maturities ranging from 2018 to 2020 that have been designated as cash flow hedges. These instruments call for this company to pay fixed rates of interest ranging from 2.96% to 5.40% on the aggregate amortized notional value of $131.7 million and receive a variable interest rate based on LIBOR on the aggregate amortized notional value. By entering into these interest rate swap agreements, the Company's 50% or less owned companies 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 nine months ended September 30 as follows (in thousands):
		2013			2012
	Interest rate swap agreements, effective portion in other comprehensive income (loss)	$	572		$	(1,290	)
	Interest rate swap agreements, ineffective portion in derivative losses, net	—			(56		)
		$	572		$	(1,346	)
	Other Derivative Instruments. The Company recognized gains (losses) on derivative instruments not designated as hedging instruments in derivative losses, net for the nine months ended September 30 as follows (in thousands):
		2013			2012
	Options on equities and equity indices	$	(4,132	)	$	(734	)
	Forward currency exchange, option and future contracts	(439		)	884
	Interest rate swap agreements	253			(1,641		)
	Commodity swap, option and future contracts:
	Exchange traded	368			(2,847		)
	Non-exchange traded	715			1,960
		$	(3,235	)	$	(2,378	)
	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 September 30, 2013, the outstanding forward currency exchange contracts translated into a net purchase of foreign currencies with an aggregate U.S. dollar equivalent of $13.0 million. These contracts enable the Company to buy currencies in the future at fixed exchange rates, which could offset possible consequences of changes in currency exchange rates with respect to the Company’s business conducted outside of the United States. The Company generally does not enter into contracts with forward settlement dates beyond twelve to eighteen months.
	The Company has entered into various interest rate swap agreements with maturities ranging from 2013 through 2018 that call for the Company to pay fixed interest rates ranging from 2.25% to 3.05% on an aggregate amortized notional value of $221.5 million (including an amortized notional value of €10.9 million or $14.8 million) and receive a variable interest rate based on LIBOR or Euribor on these notional values. As of September 30, 2013, one of the Company’s Offshore Marine Services 50% or less owned companies has entered into an interest rate swap agreement maturing in 2018 that calls for this company to pay a fixed interest rate of 1.30% on the amortized notional value of $105.6 million and receive a variable interest rate based on LIBOR on the amortized notional value. In addition, one of the Company's Shipping Services 50% or less owned companies has entered into an interest rate swap agreement maturing in 2020 that calls for this company to pay a fixed interest rate of 4.35% on the amortized notional value of $0.3 million and receive a variable interest rate based on LIBOR on the amortized notional value. The general purpose of these interest rate swap agreements is to provide protection against increases in interest rates, which might lead to higher interest costs for the Company or its 50% or less owned companies.
	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 September 30, 2013, the net market exposure to corn and sugar under these contracts was not material. The Company also enters into exchange traded positions (primarily natural gas, heating oil, crude oil, gasoline, corn and sugar) to provide value to the Company should there be a sustained decline in the price of commodities that could lead to a reduction in the market values and cash flows of the Company’s Offshore Marine Services, Inland River Services and Shipping Services businesses. As of September 30, 2013, these positions were not material.

Business_Acquisitions

Business Acquisitions	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]	'
Business Acquisitions	'
	BUSINESS ACQUISITIONS
	C-Lift Acquisition. On June 6, 2013, the Company acquired a 100% controlling interest in C-Lift through the acquisition of its partner's 50% interest for $12.7 million in cash subject to certain working capital adjustments (see Note 6). C-Lift owns and operates two liftboats in the U.S. Gulf of Mexico. The Company performed a fair value analysis and the purchase price was allocated to the acquired assets and liabilities based on their fair values resulting in no goodwill being recorded. The preliminary fair value analysis is pending completion of a final valuation for the acquired assets and liabilities.
	Pantagro Acquisition. On June 25, 2012, the Company acquired a 95% controlling interest in Pantagro-Pantanal Produtos Agropecuarious Ltda. ("Pantagro") for $0.4 million ($0.2 million in cash and $0.2 million in a note payable). Pantagro is an Argentine agricultural trading company focusing primarily on salt. The Company performed a fair value analysis and the purchase price was allocated to the acquired assets and liabilities based on their fair values resulting in no goodwill being recorded. The fair value analysis was finalized in March 2013.
	Superior Lift Boats Acquisition. On March 30, 2012, the Company acquired 18 lift boats, real property and working capital from Superior Energy Inc. (“Superior”) for $142.5 million. The Company performed a fair value analysis and the purchase price was allocated to the acquired assets and liabilities based on their fair values resulting in no goodwill being recorded. The fair value analysis was finalized in March 2013.
	Purchase Price Allocation. The following table summarizes the allocation of the purchase price for the Company’s business acquisitions during the nine months ended September 30, 2013 (in thousands):
	Trade and other receivables	$	3,250
	Other current assets	32
	Investments, at Equity, and Advances to 50% or Less Owned Companies	(13,290		)
	Property and Equipment	43,521
	Intangible Assets	1,599
	Accounts payable	(264		)
	Other current liabilities	(1,640		)
	Long-Term Debt	(22,668		)
	Purchase price(1)	$	10,540
	______________________
	-1	Purchase price is net of cash acquired of $2.2 million.

Equipment_Acquisitions_Disposi

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies	9 Months Ended
	Sep. 30, 2013
Equipment Acquisitions, Dispositions And Depreciation And Impairment Policies [Abstract]	'
Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies	'
	EQUIPMENT ACQUISITIONS, DISPOSITIONS AND DEPRECIATION AND IMPAIRMENT POLICIES
	During the nine months ended September 30, 2013, capital expenditures were $146.5 million. Equipment deliveries during the period included two specialty offshore support vessels, two liftboats, three wind farm utility vessels, two inland river liquid tank barges and four U.S.-flag harbor tugs.
	During the nine months ended September 30, 2013, the Company sold four crew boats, one mini-supply vessel, one supply vessel, three specialty offshore support vessels, five liftboats, 16 inland river dry cargo barges, eight inland river liquid tank barges, eight U.S.-flag harbor tugs and other property and equipment for net proceeds of $214.7 million ($205.7 million in cash, $0.2 million in vendor credits and $8.8 million in seller financing) and gains of $49.0 million, of which $34.4 million were recognized currently and $14.6 million were deferred. In addition, the Company recognized previously deferred gains of $2.1 million. Two of the specialty offshore support vessels and the supply vessel were sold to certain of the Company's Offshore Marine Services' 50% or less owned companies for $83.7 million (see Note 6).
	The Company has sold certain equipment to its 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 nine months ended September 30 was as follows (in thousands):
		2013			2012
	Balance at beginning of period	$	111,514		$	117,192
	Deferred gains arising from asset sales	14,609			7,280
	Amortization of deferred gains included in operating expenses as a reduction to rental expense	(7,707		)	(13,573		)
	Amortization of deferred gains included in gains on asset dispositions and impairments, net	(2,146		)	(7,872		)
	Balance at end of period	$	116,270		$	103,027
	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 September 30, 2013, the estimated useful life (in years) of each of the Company’s major categories of new equipment was as follows:
	Offshore support vessels (excluding wind farm utility)	20
	Wind farm utility vessels	10
	Inland river dry cargo and deck barges	20
	Inland river liquid tank barges	25
	Inland river towboats	25
	U.S.-flag product tankers	25
	RORO(1) vessels	20
	Harbor tugs	25
	Ocean liquid tank barges	25
	Terminal and manufacturing facilities	20
	______________________
	-1	Roll on/Roll off ("RORO").
	The Company performs an impairment analysis of long-lived assets used in operations, including intangible assets, when indicators of impairment are present. If the carrying value of the assets is not recoverable, as determined by the estimated undiscounted cash flows, the carrying value of the assets is reduced to fair value. Generally, fair value is determined using valuation techniques, such as expected discounted cash flows or appraisals, as appropriate. During the nine months ended September 30, 2013, the Company recognized impairment charges of $3.0 million related to two of Shipping Services' harbor tugs while under construction, which were sold and leased back upon their completion.

Investments_At_Equity_And_Adva

Investments, At Equity, And Advances To 50% Or Less Owned Companies	9 Months Ended
	Sep. 30, 2013
Equity Method Investment, Summarized Financial Information [Abstract]	'
Investments, At Equity, And Advances To 50% Or Less Owned Companies	'
	INVESTMENTS, AT EQUITY, AND ADVANCES TO 50% OR LESS OWNED COMPANIES
	OSV Partners. On August 13, 2013, the Company and Breem Transportation Services LLC formed SEACOR OSV Partners GP LLC and SEACOR OSV Partners I LP (collectively "OSV Partners") to own and operate six offshore support vessels, one of which was acquired during the third quarter. During the nine months ended September 30, 2013, the Company contributed $1.8 million in capital and provided financing of $7.6 million. During the fourth quarter, OSV Partners anticipates closing on a private placement equity offering with third party limited partner members and a bank financing arrangement.
	Dorian. On July 25, 2013, the Company contributed $57.0 million to Dorian in exchange for a 25% noncontrolling ownership interest. The contribution included $42.1 million in net cash and other consideration valued at $14.9 million that included certain progress payments made toward the construction of the two liquefied petroleum gas tankers (Very Large Gas Carriers, otherwise known as VLGCs), the construction contracts for the two VLGCs and the options to construct additional VLGCs. In addition to the VLGC construction contracts, Dorian currently operates a fleet of three VLGCs in international trade.
	C-Lift. C-Lift was a 50% or less owned company established to construct and operate liftboats. On June 6, 2013, the Company acquired a 100% controlling interest in C-Lift through the acquisition of its partner's 50% interest for $12.7 million in cash subject to certain working capital adjustments (see Note 4). Upon the acquisition, the Company adjusted its investment in C-Lift to fair value resulting in the recognition of a gain of $4.2 million, net of tax, which is included in equity in earnings (losses) of 50% or less owned companies in the accompanying condensed consolidated statements of income.
	Sea-Cat Crewzer II. On January 23, 2013, the Company and another offshore support vessel operator formed Sea-Cat Crewzer II LLC (“Sea-Cat Crewzer II”) to own and operate two high speed offshore catamaran crew boats. The Company and its partner each contributed capital of $23.0 million in cash. Sea-Cat Crewzer II then purchased two high speed offshore catamaran crew boats from the Company for $47.3 million ($44.5 million in cash and $2.8 million in seller financing).
	MexMar. During the nine months ended September 30, 2013, the Company made an additional cash investment of $5.9 million in Mantenimiento Express Maritimo, S.A.P.I. de C.V. ("MexMar"), an Offshore Marine Services 50% or less owned company. During the nine months ended September 30, 2013, MexMar purchased one offshore support vessel from the Company for $36.4 million ($30.4 million in cash and $6.0 million in seller financing). During the nine months ended September 30, 2013, MexMar repaid the $6.0 million of seller financing and the Company provided an additional $1.7 million advance for the purchase of another offshore support vessel from a third party, which was repaid.
	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 nine months ended September 30, 2013, the Company contributed additional capital of $4.0 million to fund SCFCo’s operations, provided net temporary working capital advances of $2.3 million and received working capital repayments of $1.8 million. As of September 30, 2013, the Company had outstanding loans to SCFCo Holdings of $3.4 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 nine months ended September 30, 2013, the Company and its partner each made a working capital advance of $2.5 million to Bunge-SCF Grain and received $0.5 million of repayments on working capital advances. As of September 30, 2013, the total outstanding balance of working capital advances was $7.0 million.
	Witt O'Brien's. During the nine months ended September 30, 2013, the Company received dividends of $1.5 million from Witt O'Brien's LLC.
	Other. During the nine months ended September 30, 2013, the Company made a $0.5 million capital contribution to one of its industrial aviation businesses in Asia. During the nine months ended September 30, 2013, the Company received a $1.0 million repayment on advances made to one of its industrial aviation businesses in Asia and dividends of $6.5 million from certain Offshore Marine Services 50% or less owned companies.
	Guarantees. The Company has guaranteed the payment of amounts owed by one of its 50% or less owned companies under a vessel charter and has guaranteed amounts owed under banking facilities by certain of its 50% or less owned companies. As of September 30, 2013, the total amount guaranteed by the Company under these arrangements was $15.3 million. In addition, as of September 30, 2013, the Company had uncalled capital commitments to two of its 50% or less owned companies for a total of $2.4 million.

Commitments_And_Contingencies

Commitments And Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments And Contingencies	'
	COMMITMENTS AND CONTINGENCIES
	As of September 30, 2013, the Company’s unfunded capital commitments were $366.5 million and included: 15 offshore support vessels for $100.6 million; two inland river liquid tank barges for $1.7 million; five inland river towboats for $6.3 million; two U.S.-flag product tankers for $250.5 million and other equipment and improvements for $7.4 million. Of these commitments, $25.0 million is payable during the remainder of 2013, $300.5 million is payable during 2014-2015 and $41.0 million is payable during 2016-2017. Subsequent to September 30, 2013, the Company committed to purchase two offshore support vessels and one inland river towboat for a total of $39.2 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 U.S. Court of Appeals for the Fifth Circuit ("Fifth Circuit"). The claimants' opening brief was submitted on May 7, 2012, and the claimants filed a reply brief on June 1, 2012. Oral argument was not requested by the Fifth Circuit. On December 13, 2012, the Fifth Circuit affirmed the judgment of the district court. The claimants have not petitioned the United States Supreme Court for a writ of certiorari and their deadline to do so has expired.
	With respect to the one claim filed by a Company employee, that individual also commenced a separate action in the MDL entitled DuWayne Mason v. Seacor Marine, LLC, No. 2:11-CV-00826 (E.D. La.), in which he alleges sustaining personal injuries not only in connection with responding to the explosion and fire, but also in the months thereafter in connection with the clean-up of oil and dispersants while a member of the crew of the M/V Seacor Vanguard. Although the case is subject to the MDL Court's stay of individual proceedings, on July 16, 2012 the employee sought to sever his case from the MDL. On March 5, 2013, the Court denied the motion, and on April 2, 2013, the employee filed a motion asking the Court to reconsider. The Company filed its response opposing the employee's motion on April 30, 2013, and on May 3, 2013, the Court denied the motion.  On May 22, 2013, the employee filed a Notice of Appeal to the Fifth Circuit.  On July 24, 2013, the Company filed a motion to dismiss for lack of appellate jurisdiction. The Fifth Circuit granted the Company's motion to dismiss on August 16, 2013.
	On July 20, 2010, two individuals purporting to represent a class commenced a civil action in the Civil District Court for the Parish of Orleans in the State of Louisiana, John Wunstell, Jr. and Kelly Blanchard v. BP, et al., No. 2010-7437 (Division K) (the “Wunstell Action”), in which they assert, among other theories, that Mr. Wunstell suffered injuries as a result of his exposure to certain noxious fumes and chemicals in connection with the provision of remediation, containment and response services by O'Brien's Response Management Inc. ("ORM"), a subsidiary of the Company prior to the ORM Transaction (as defined in the Company's Annual Report on Form 10-K for the year ended December 31, 2012). The action now is part of the overall MDL. The complaint also seeks to establish a “class-wide court-supervised medical monitoring program” for all individuals “participating in BP's Deepwater Horizon Vessels of Opportunity Program and/or Horizon Response Program” who allegedly experienced injuries similar to those of Mr. Wunstell. The Company believes this lawsuit has no merit and will continue to vigorously defend the action and pursuant to contractual agreements with the responsible party, the responsible party has agreed, subject to certain potential limitations, to indemnify and defend ORM in connection with the Wunstell Action and claims asserted in the MDL, discussed further below. Although the Company is unable to estimate the potential exposure, if any, resulting from this matter, the Company does not expect it will have a material effect on the Company's consolidated financial position or its results of operations.
	On December 15, 2010, ORM and National Response Corporation ("NRC"), subsidiaries of the Company prior to the ORM Transaction and SES Business Transaction (as defined in the Company's Annual Report on Form 10-K for the year ended December 31, 2012), respectively, were named as defendants in one of the several consolidated “master complaints” that have been filed in the overall MDL. The master complaint naming ORM and NRC asserts various claims on behalf of a putative class against multiple defendants concerning the clean-up activities generally, and the use of dispersants specifically. By court order, the Wunstell Action has been stayed as a result of the filing of the referenced master complaint. The Company believes that the claims asserted against ORM and NRC in the master complaint have no merit and on February 28, 2011, ORM and NRC moved to dismiss all claims against them in the master complaint on legal grounds. On September 30, 2011, the Court granted in part and denied in part the motion to dismiss that ORM and NRC had filed (an amended decision was issued on October 4, 2011 that corrected several grammatical errors and non-substantive oversights in the original order). Although the Court refused to dismiss the referenced master complaint in its entirety at that time, the Court did recognize the validity of the “derivative immunity” and “implied preemption” arguments that ORM and NRC advanced and directed ORM and NRC to (i) conduct limited discovery to develop evidence to support those arguments and (ii) then re-assert the arguments. The Court did, however, dismiss all state-law claims and certain other claims that had been asserted in the referenced master complaint, and dismissed the claims of all plaintiffs that have failed to allege a legally-sufficient injury. A schedule for limited discovery and motion practice was established by the Court and, in accordance with that schedule, ORM and NRC filed for summary judgment re-asserting their derivative immunity and implied preemption arguments on May 18, 2012. Those motions were argued on July 13, 2012 and are still pending decision. In addition to the indemnity provided to ORM, pursuant to contractual agreements with the responsible party, the responsible party has agreed, subject to certain potential limitations, to indemnify and defend ORM and NRC in connection with these claims in the MDL. Although the Company is unable to estimate the potential exposure, if any, resulting from this matter, the Company does not expect it will have a material effect on the Company's consolidated financial position or its results of operations.
	Subsequent to the filing of the referenced master complaint, nine additional individual civil actions have been filed in or removed to the U.S. District Court for the Eastern District of Louisiana concerning the clean-up activities generally, which name the Company, ORM and/or NRC as defendants or third-party defendants and are part of the overall MDL. On April 8, 2011, ORM was named as a defendant in Johnson Bros. Corporation of Louisiana v. BP, PLC, et al., No. 2:11-CV-00781 (E.D. La.), which is a suit by an individual business seeking damages allegedly caused by a delay on a construction project alleged to have resulted from the clean-up operations. On April 15, 2011, ORM and NRC were named as defendants in James and Krista Pearson v. BP Exploration & Production, Inc. ("BP Exploration"), et al., No. 2:11-CV-00863 (E.D. La.), which is a suit by a husband and wife, who allegedly participated in the clean-up effort and are seeking damages for personal injury, property damage to their boat, and amounts allegedly due under contract. On April 15, 2011, ORM and NRC were named as defendants in Thomas Edward Black v. BP Exploration, et al., No. 2:11-CV-00867 (E.D. La.), which is a suit by an individual who is seeking damages for lost income because he allegedly could not find work in the fishing industry after the oil spill. On April 20, 2011, a complaint was filed in Darnell Alexander, et al. v. BP, PLC, et al., No. 2:11-CV-00951 (E.D. La.) on behalf of 117 individual plaintiffs that seek to adopt the allegations made in the referenced master complaint against ORM and NRC (and the other defendants). Plaintiffs in this matter have since been granted leave to amend their complaint to include 410 additional individual plaintiffs. On October 3, 2012, ORM and NRC were served with a Rule 14(c) Third-Party Complaint by Jambon Supplier II, L.L.C. and Jambon Marine Holdings L.L.C. in their Limitation of Liability action, In the Matter of Jambon Supplier II, L.L.C., et al., No. 2:12-CV-00426 (E.D. La.). This Third-Party Complaint alleges that if claimant David Dinwiddie, who served as a clean-up crewmember aboard the M/V JAMBON SUPPLIER II vessel during the clean-up efforts, was injured as a result of his exposure to dispersants and chemicals during the course and scope of his employment, then said injuries were caused by the third-party defendants. On November 25, 2012, ORM was named as a defendant in Victoria Sanchez v. American Pollution Control Corp. et al., No. 2:12-CV-00164 (E.D. La.), a maritime suit filed by an individual who allegedly participated in the clean-up effort and sustained personal injuries during the course of such employment. On December 17, 2012, the Court unsealed a False Claims Act lawsuit naming ORM as a defendant, Dillon v. BP, PLC et al., No. 2:12-CV-00987 (E.D. La.)., which is a suit by an individual seeking damages and penalties arising from alleged false reports and claims made to the federal government with respect to the amount of oil burned and dispersed during the clean-up. The federal government has declined to intervene in this suit. On April 8, 2013, the Company, ORM, and NRC were named as defendants in William and Dianna Fitzgerald v. BP Exploration et al., No. 2:13-CV-00650 (E.D. La.), which is a suit by a husband and wife whose son allegedly participated in the clean-up effort and became ill as a result of his exposure to oil and dispersants. Finally, on April 17, 2013, ORM was named as a defendant in Danos et al. v. BP America Production Co. et al., No. 2:13-CV-03747 (removed to E.D. La.), which is a suit by eight individuals seeking damages for dispersant exposure either as a result of their work during clean-up operations or as a result of their residence in the Gulf. By court order, all nine of these additional individual cases have been stayed until further notice. The Company is unable to estimate the potential exposure, if any, resulting from these matters but believes they are without merit and does not expect that they will have a material effect on its consolidated financial position or its results of operations.
	On February 18, 2011, Triton Asset Leasing GmbH, Transocean Holdings LLC, Transocean Offshore Deepwater Drilling Inc., and Transocean Deepwater Inc. (collectively “Transocean”) named ORM and NRC as third-party defendants in a Rule 14(c) Third-Party Complaint in Transocean's own Limitation of Liability Act action, which is part of the overall MDL, tendering to ORM and NRC the claims in the referenced master complaint that have already been asserted against ORM and NRC. Transocean, Cameron International Corporation, Halliburton Energy Services, Inc., and M-I L.L.C. also filed cross-claims against ORM and NRC for contribution and tort indemnity should they be found liable for any damages in Transocean's Limitation of Liability Act action and ORM and NRC have asserted counterclaims against those same parties for identical relief. Weatherford U.S., L.P. and Weatherford International, Inc. (collectively "Weatherford") had also filed cross-claims against ORM and NRC, but moved to voluntarily dismiss these cross-claims without prejudice on February 8, 2013. The Court granted Weatherford's motion that same day. As indicated above, the Company is unable to estimate the potential exposure, if any, resulting from these actions but believes they are without merit and does not expect that these matters will have a material effect on its consolidated financial position or its results of operations.
	On November 16, 2012, 668 individuals who served as beach clean-up workers in Escambia County, Florida during the Deepwater Horizon oil spill response commenced a civil action in the Circuit Court for the First Judicial Circuit of Florida, in and for Escambia County, Abney et al. v. Plant Performance Services, LLC et al., No. 2012-CA-002947, in which they allege, among other things, that ORM and other defendants engaged in the contamination of Florida waters and beaches in violation of Florida Statutes Chapter 376 and injured the plaintiffs by exposing them to dispersants during the course and scope of their employment. The case was removed to the U.S. District Court for the Northern District of Florida on January 13, 2013, Abney et al. v. Plant Performance Services, LLC et la., No. 3:13-CV-00024 (N.D. Fla.), and on January 16, 2013, the United States Judicial Panel on Multidistrict Litigation (“JPML”) issued a Conditional Transfer Order (“CTO”) transferring the case to the MDL, subject to any timely-filed notice of objection from the plaintiffs. Upon receipt of a notice of objection from the plaintiffs, a briefing schedule was set by the JPML, and so a stay of proceedings and suspension of deadlines was sought and obtained by the Court in the U.S. District Court for the Northern District of Florida. Following briefing before the JPML, the case was transferred to the U.S. District Court for the Eastern District of Louisiana and consolidated with the MDL on April 2, 2013. On April 22, 2013, a companion case to this matter was filed in the U.S. District Court for the Northern District of Florida, Abood et al. v. Plant Performance Services, LLC et al., No. 3:13-CV-00284 (N.D. Fla.), which alleges identical allegations against the same parties but names an additional 174 plaintiffs, all of whom served as clean-up workers in various Florida counties during the Deepwater Horizon oil spill response.  A CTO was issued by the JPML on May 2, 2013, no objection was filed by the plaintiffs, and the case was transferred to the U.S. District Court for the Eastern District of Louisiana and consolidated with the MDL on May 10, 2013.  By court order, both of these matters have been stayed until further notice. The Company is unable to estimate the potential exposure, if any, resulting from these matters but believes they are without merit and does not expect that these matters will have a material effect on its consolidated financial position or its results of operations.
	Separately, on March 2, 2012, the Court announced that BP Exploration and BP America Production Company ("BP America") (collectively "BP") and the plaintiffs had reached an agreement on the terms of two proposed class action settlements that will resolve, among other things, plaintiffs' economic loss claims and clean-up related claims against BP. The parties filed their proposed settlement agreements on April 18, 2012 along with motions seeking preliminary approval of the settlements. The Court held a hearing on April 25, 2012 to consider those motions and preliminarily approved both settlements on May 2, 2012. A final fairness hearing took place on November 8, 2012. The Court granted final approval to the Economic and Property Damages Class Action Settlement on December 21, 2012, and granted final approval to the Medical Benefits Class Action Settlement on January 11, 2013. Both class action settlements are currently on appeal to the Fifth Circuit. Although neither the Company, ORM, or NRC are parties to the settlement agreements, the Company, ORM, and NRC are listed as released parties on the releases accompanying both settlement agreements. As the releases for both settlements have been deemed valid and enforceable by the district court, if the Fifth Circuit affirms these decisions, class members who did not file timely requests for exclusion will be barred from pursuing economic loss, property damage, personal injury, medical monitoring, and/or other released claims against the Company, ORM, and NRC. At this time, the Company expects these settlements to reduce ORM's potential exposure, if any, from some of the pending actions described above, and continues to evaluate the settlements' impacts on these cases.
	On January 29, 2013, HEPACO, LLC ("HEPACO"), served a demand for arbitration upon ORM, in which HEPACO claims that ORM owes HEPACO an additional fee of $20,291,178.92 under the parties' Management Services Agreement (“MSA”), dated June 1, 2010.  According to HEPACO, the MSA requires ORM to pay HEPACO an additional fee of 30% of total charges paid under the MSA ("Surcharge") to compensate HEPACO for U.S. Longshoremen's and Harbor Workers' insurance or Jones Act insurance and related risks attendant to the work when contract requires labor to be performed over, adjoining and/or in water. ORM denies liability for the Surcharge, intends to vigorously defend against the claim, and has sought indemnity for any resulting judgment and related attorneys fees from BP America and BP Exploration. ORM has advised BP that, pursuant to the Bridge Agreement HOU-WL4-3066 between BP and ORM, effective as of June 1, 2010, under which ORM managed and oversaw, for BP, subcontractors, such as HEPACO, in connection with on-shore services related to the BP Deepwater Horizon oil spill, BP ultimately is responsible for the payment of the Surcharge should HEPACO be determined to be entitled to recover it under the MSA.
	ORM is defending against three collective action lawsuits, each asserting failure to pay overtime with respect to individuals who provided service on the Deepwater Horizon oil spill response (the “DPH FLSA Actions”) under the Fair Labor Standards Act (“FLSA”).  These cases - Dennis Prejean v. O'Brien's Response Management Inc. (E.D. La., Case No.: 2:12-cv-01045) (the “Prejean Action”); Baylor Singleton et. al. v. O'Brien's Response Management Inc. et. al. (E.D. La., Case No.: 2:12-cv-01716) (the “Singleton Action”); and Himmerite et al. v. O'Brien's Response Management Inc. et al. (E.D. La., Case No.: 2:12-cv-01533) (the “Himmerite Action”) - were each brought on behalf of certain individuals who worked on the Deepwater Horizon oil spill response and who were classified as independent contractors.  The Prejean, Himmerite and Singleton Actions were each filed in the United States District Court for the Eastern District of Louisiana and then subsequently consolidated with the overall MDL, in which the Himmerite and Singleton Actions were stayed pursuant to procedures of the MDL.  However, all three cases were severed from the MDL on September 19, 2013, and referred to a Magistrate Judge for pretrial case management, including issuing a scheduling order, overseeing discovery, and any other preliminary matters. The Himmerite and Singleton Actions are still pre-answer. 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 is fully briefed and submitted. The pending Motion for Conditional Certification was referred by order dated September 19, 2013 to the Magistrate Judge for his report and recommendation.  The limitations periods for potential plaintiffs to opt-in to the Prejean, Himmerite and Singleton Actions have all been tolled pending further action by the Court.  The Company is unable to estimate the potential exposure, if any, resulting from any of these DWH FLSA Actions, but believes they are without merit and will continue to vigorously defend against them.
	In the course of the Company's business, it may agree to indemnify the counterparty to an agreement.  If the indemnified party makes a successful claim for indemnification, the Company would be required to reimburse that party in accordance with the terms of the indemnification agreement.  Indemnification agreements generally are subject to threshold amounts, specified claim periods and other restrictions and limitations.
	In connection with the SES Business Transaction and the ORM Transaction, the Company remains contingently liable for certain indemnification obligations, including potential liabilities relating to work performed in connection with the Deepwater Horizon oil spill response. In the case of the SES Business Transaction, such potential liabilities may not exceed the purchase consideration received by the Company for the SES Business Transaction and in the case of the ORM Transaction, are subject to a negotiated cap. The Company currently is indemnified under contractual agreements with BP with respect to such potential liabilities.
	In the normal course of its business, the Company becomes involved in various other litigation matters including, among other things, claims by third parties for alleged property damages and personal injuries. Management has used estimates in determining the Company's potential exposure to these matters and has recorded reserves in its financial statements related thereto where appropriate. It is possible that a change in the Company's estimates of that exposure could occur, but the Company does not expect such changes in estimated costs would have a material effect on the Company's consolidated financial position or its results of operations.

Multiemployer_Pension_Plans

Multiemployer Pension Plans	9 Months Ended
	Sep. 30, 2013
Compensation and Retirement Disclosure [Abstract]	'
Multiemployer Pension Plans	'
	MULTI-EMPLOYER PENSION PLANS
	During the nine months ended September 30, 2013, the Company received notification from the American Maritime Officers Pension Plan (the "AMOPP”) that based on an actuarial valuation performed as of September 30, 2012, if the Company chooses to withdraw from the AMOPP, its withdrawal liability will be $45.6 million. That liability may change in future years based on various factors, primarily employee census. As of September 30, 2013, the Company has no intention to withdraw from the AMOPP and no deficit amounts have been invoiced. Depending upon the results of the future actuarial valuations and the ten-year rehabilitation plan, it is possible that the AMOPP will experience further funding deficits, requiring the Company to recognize additional payroll related operating expenses in the periods invoices are received or contribution levels are increased.
	During the nine months ended September 30, 2013, the Company also received notification from the United Kingdom Merchant Navy Officers Pension Fund ("MNOPF") that the results of a 2012 actuarial valuation indicated that an additional net funding deficit of £120.0 million had developed since the previous actuarial valuation in 2009 and the Company's allocable share of the additional deficit was £1.7 million. During the nine months ended September 30, 2013, the Company received the invoice for the additional funding deficit and recognized additional payroll related operating expenses of $2.7 million. Depending upon the results of the future actuarial valuations, it is possible that the MNOPF will experience further funding deficits, requiring the Company to recognize additional payroll related operating expenses in the periods invoices are received.

LongTerm_Debt_and_Capital_Leas

Long-Term Debt and Capital Lease Obligations	9 Months Ended
	Sep. 30, 2013
Long-term Debt and Capital Lease Obligations [Abstract]	'
Long-Term Debt and Capital Lease Obligations	'
	LONG-TERM DEBT AND CAPITAL LEASE OBLIGATIONS
	On August 9, 2013, the Company voluntarily terminated the SEACOR revolving credit facility.
	As of September 30, 2013, the Company had outstanding letters of credit totaling $28.1 million with various expiration dates through 2016.
	During the nine months ended September 30, 2013, the Company made scheduled payments on long-term debt and capital lease obligations of $13.1 million and had net borrowings of $4.2 million under inventory financing arrangements.
	SEACOR’s Board of Directors has previously authorized the Company to purchase any or all of its 7.375% Senior Notes due 2019, which may be acquired through open market purchases, privately negotiated transactions or otherwise, depending on market conditions. During the nine months ended September 30, 2013, the Company did not repurchase any of its 7.375% Senior Notes due 2019.

Stock_Repurchases

Stock Repurchases	9 Months Ended
	Sep. 30, 2013
Stock Repurchases [Abstract]	'
Stock Repurchases	'
	STOCK REPURCHASES
	SEACOR’s Board of Directors previously approved a securities repurchase plan that authorizes the Company to acquire shares of SEACOR common stock, par value $0.01 per share (“Common Stock”), which may be acquired through open market purchases, privately negotiated transactions or otherwise, depending on market conditions. During the nine months ended September 30, 2013, the Company did not acquire any shares of Common Stock for treasury. As of September 30, 2013, the remaining authority under the repurchase plan was $100.0 million.

Earnings_Per_Common_Share_of_S

Earnings Per Common Share of SEACOR	9 Months Ended
	Sep. 30, 2013
Earnings Per Common Share of SEACOR [Abstract]	'
Earnings Per Common Share of SEACOR	'
	EARNINGS PER COMMON SHARE OF SEACOR
	Basic earnings per common share of SEACOR are computed based on the weighted average number of common shares issued and outstanding during the relevant periods. Diluted earnings per common share of SEACOR are computed based on the weighted average number of common shares issued and outstanding plus the effect of potentially dilutive securities through the application of the treasury stock and if-converted methods. Dilutive securities for this purpose assumes restricted stock grants have vested, common shares have been issued pursuant to the exercise of outstanding stock options and common shares have been issued pursuant to the conversion of all outstanding convertible notes.
	Computations of basic and diluted earnings per common share of SEACOR were as follows (in thousands, except share data):
		Three Months Ended September 30,					Nine Months Ended September 30,
		Net Income Attributable to SEACOR		Average O/S Shares	Per Share		Net Income Attributable to SEACOR		Average O/S Shares	Per Share
							(As Restated)			(As Restated)
	2013
	Basic Weighted Average Common Shares Outstanding	$	30,291	19,964,695	$	1.52	$	28,574	19,843,778	$	1.44
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—		436,364			—		354,671
	Convertible Notes(2)	3,086		4,200,525			—		—
	Diluted Weighted Average Common Shares Outstanding	$	33,377	24,601,584	$	1.36	$	28,574	20,198,449	$	1.41
		Three Months Ended September 30,					Nine Months Ended September 30,
		Net Income Attributable to SEACOR		Average O/S Shares	Per Share		Net Income Attributable to SEACOR		Average O/S Shares	Per Share
	2012
	Basic Weighted Average Common Shares Outstanding	$	16,102	20,432,997	$	0.79	$	63,839	20,512,118	$	3.11
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—		307,459			—		326,350
	Diluted Weighted Average Common Shares Outstanding	$	16,102	20,740,456	$	0.78	$	63,839	20,838,468	$	3.06
	______________________
	-1	For the three months ended September 30, 2013 and 2012, diluted earnings per common share of SEACOR excluded 115,832 and 655,168 of certain share awards, respectively, as the effect of their inclusion in the computation would be anti-dilutive. For the nine months ended September 30, 2013 and 2012, diluted earnings per share of SEACOR excluded 303,313 and 555,768 of certain share awards, respectively, as the effect of their inclusion in the computation would be anti-dilutive.
	-2	For the nine months ended September 30, 2013, diluted earnings per common share of SEACOR excluded 4,200,525 common shares issuable pursuant to the Company's 2.5% Convertible Senior Notes as the effect of their inclusion in the computation would be anti-dilutive.

Share_Based_Compensation

Share Based Compensation	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Share Based Compensation	'
	SHARE BASED COMPENSATION
	Transactions in connection with the Company’s share based compensation plans during the nine months ended September 30, 2013 were as follows:
	Director stock awards granted	2,000
	Employee Stock Purchase Plan (“ESPP”) shares issued	31,586
	Restricted stock awards granted	148,300
	Restricted stock awards canceled	18,000
	Shares released from Deferred Compensation Plan	1,692
	Stock Option Activities:
	Outstanding as of December 31, 2012	1,281,821
	Granted(1)	480,762
	Exercised	(278,354	)
	Forfeited	(800	)
	Expired	(1,576	)
	Outstanding as of September 30, 2013	1,481,853
	Shares available for future grants and ESPP purchases as of September 30, 2013	558,145
	______________________
	-1	During the nine months ended September 30, 2013, the Company granted 318,012 stock options to existing option holders under make-whole provisions upon the Spin-off of Era Group.

Segment_Information

Segment Information	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Segment Information	'
	SEGMENT INFORMATION
	Accounting standards require public business enterprises to report information about each of their operating business segments that exceed certain quantitative thresholds or meet certain other reporting requirements. Operating business segments have been defined as components of an enterprise about which separate financial information is available and is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. Certain reclassifications of prior period information have been made to conform to the current period's reportable segment presentation as a result of the Company's presentation of discontinued operations (see Notes 1 and 14). The Company’s basis of measurement of segment profit or loss is as previously described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.
	The following tables summarize the operating results, capital expenditures and assets of the Company's reportable segments.
		Offshore		Inland		Shipping		Ethanol and		Other		Corporate		Total
		Marine		River		Services		Industrial		$’000		and		$’000
		Services		Services		$’000		Alcohol				Eliminations
		$’000		$’000				$’000				$’000
	For the three months ended
	30-Sep-13
	Operating Revenues:
	External customers	156,173		51,950		48,200		52,580		27,881		—		336,784
	Intersegment	25		792		—		—		—		(817	)	—
		156,198		52,742		48,200		52,580		27,881		(817	)	336,784
	Costs and Expenses:
	Operating	95,113		38,473		28,215		52,390		26,141		(792	)	239,540
	Administrative and general	14,132		3,431		5,133		428		1,429		6,910		31,463
	Depreciation and amortization	16,470		6,869		7,841		1,489		92		742		33,503
		125,715		48,773		41,189		54,307		27,662		6,860		304,506
	Gains on Asset Dispositions	15,343		783		3,104		—		—		—		19,230
	Operating Income (Loss)	45,826		4,752		10,115		(1,727	)	219		(7,677	)	51,508
	Other Income (Expense):
	Derivative gains (losses), net	32		—		—		1,129		(380	)	(1,084	)	(303	)
	Foreign currency (gains) losses, net	1,937		(89	)	6		—		15		361		2,230
	Other, net	—		—		540		—		(3	)	(60	)	477
	Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,527		80		(1,413	)	—		36		—		230
	Segment Profit (Loss)	49,322		4,743		9,248		(598	)	(113	)
	Other Income (Expense) not included in Segment Profit (Loss)													(7,389	)
	Less Equity Earnings (Losses) included in Segment Profit (Loss)													(230	)
	Income Before Taxes, Equity Earnings and Discontinued Operations													46,523
		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 nine months ended
	30-Sep-13
	Operating Revenues:
	External customers	418,815		148,153		142,779		146,807		62,857		—		919,411
	Intersegment	77		2,023		—		—		—		(2,100	)	—
		418,892		150,176		142,779		146,807		62,857		(2,100	)	919,411
	Costs and Expenses:
	Operating	282,725		110,055		84,383		145,837		59,589		(2,023	)	680,566
	Administrative and general	43,194		11,376		16,434		1,566		4,408		24,848		101,826
	Depreciation and amortization	49,217		21,031		23,545		4,467		287		2,287		100,834
		375,136		142,462		124,362		151,870		64,284		25,112		883,226
	Gains on Asset Dispositions	25,577		5,776		149		—		1,907		141		33,550
	and Impairments, Net
	Operating Income (Loss)	69,333		13,490		18,566		(5,063	)	480		(27,071	)	69,735
	Other Income (Expense):
	Derivative gains (losses), net	357		—		—		1,641		12		(5,245	)	(3,235	)
	Foreign currency losses, net	(2,160	)	(7	)	(9	)	—		(321	)	(200	)	(2,697	)
	Other, net	11		—		742		—		51		(129	)	675
	Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	10,534		(2,306	)	(3,321	)	—		2,164		—		7,071
	Segment Profit (Loss)	78,075		11,177		15,978		(3,422	)	2,386
	Other Income (Expense) not included in Segment Profit (Loss)													(11,214	)
	Less Equity Earnings (Losses) included in Segment Profit (Loss)													(7,071	)
	Income Before Taxes, Equity Earnings and Discontinued Operations													53,264
	Capital Expenditures	85,324		22,138		36,218		656		384		1,763		146,483
	As of September 30, 2013
	Property and Equipment:
	Historical cost	1,160,334		473,349		495,877		43,812		3,992		30,951		2,208,315
	Accumulated depreciation	(457,454	)	(140,747	)	(216,270	)	(10,081	)	(600	)	(10,452	)	(835,604	)
		702,880		332,602		279,607		33,731		3,392		20,499		1,372,711
	Construction in progress	95,552		23,814		7,323		632		2,119		41		129,481
	798,432		356,416		286,930		34,363		5,511		20,540		1,502,192
Investments, at Equity, and Advances to 50% or Less Owned Companies	99,191		57,445		123,354		—		85,901		—		365,891
Inventories	6,187		2,277		1,794		12,856		2,328		—		25,442
Goodwill	13,367		2,759		1,852		—		—		—		17,978
Intangible Assets	4,116		8,049		1,002		29		387		—		13,583
Other current and long-term assets, excluding cash and near cash assets(3)	160,248		45,881		19,480		6,765		62,863		23,060		318,297
Segment Assets	1,081,541		472,827		434,412		54,013		156,990
Cash and near cash assets(3)													608,341
Total Assets													2,851,724
______________________
-1	Operating revenues includes $144.2 million of tangible product sales and operating expenses includes $143.3 million of costs of goods sold.
-2	Inventories includes raw materials of $2.7 million and work in process of $2.1 million.
-3	Cash and near cash assets includes cash, cash equivalents, restricted cash, marketable securities, construction reserve funds and Title XI reserve funds.
	Offshore		Inland		Shipping		Ethanol and		Other		Corporate		Total
	Marine		River		Services		Industrial		$’000		and		$’000
	Services		Services		$’000		Alcohol				Eliminations
	$’000		$’000				$’000				$’000
For the three months ended
September 30, 2012
Operating Revenues:
External customers	134,296		53,293		45,157		47,813		58,296		—		338,855
Intersegment	26		—		—		—		40		(66	)	—
	134,322		53,293		45,157		47,813		58,336		(66	)	338,855
Costs and Expenses:
Operating	88,842		38,320		28,089		45,472		53,287		(5	)	254,005
Administrative and general	14,795		3,480		6,567		545		5,635		8,487		39,509
Depreciation and amortization	16,051		7,335		7,776		1,578		753		854		34,347
	119,688		49,135		42,432		47,595		59,675		9,336		327,861
Gains (Losses) on Asset Dispositions and Impairments, Net	6,585		3,503		145		—		(1,169	)	—		9,064
Operating Income (Loss)	21,219		7,661		2,870		218		(2,508	)	(9,402	)	20,058
Other Income (Expense):
Derivative losses, net	—		—		—		(1,035	)	(838	)	(157	)	(2,030	)
Foreign currency gains (losses), net	717		33		8		—		(25	)	295		1,028
Other, net	—		—		7,145		—		—		(47	)	7,098
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,238		(2,227	)	(551	)	—		243		—		(1,297	)
Segment Profit (Loss)	23,174		5,467		9,472		(817	)	(3,128	)
Other Income (Expense) not included in Segment Profit (Loss)													(7,916	)
Less Equity Earnings (Losses) included in Segment Profit (Loss)													1,297
Income Before Taxes, Equity Earnings and Discontinued Operations													18,238
	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 nine months ended
30-Sep-12
Operating Revenues:
External customers	378,606		160,085		133,606		146,370		127,262		—		945,929
Intersegment	78		—		108		—		75		(261	)	—
	378,684		160,085		133,714		146,370		127,337		(261	)	945,929
Costs and Expenses:
Operating	258,266		110,966		83,875		140,078		113,930		(146	)	706,969
Administrative and general	39,797		11,235		16,939		1,404		16,332		25,094		110,801
Depreciation and amortization	44,792		21,586		22,755		4,208		2,153		1,775		97,269
	342,855		143,787		123,569		145,690		132,415		26,723		915,039
Gains (Losses) on Asset Dispositions and Impairments, Net	9,054		6,288		2,005		—		(1,164	)	—		16,183
Operating Income (Loss)	44,883		22,586		12,150		680		(6,242	)	(26,984	)	47,073
Other Income (Expense):
Derivative gains (losses), net	—		—		—		(1,756	)	261		(939	)	(2,434	)
Foreign currency gains (losses), net	1,486		(60	)	17		—		(10	)	232		1,665
Other, net	11		—		7,432		—		—		14		7,457
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	4,068		(1,538	)	(1,542	)	6,154		(483	)	—		6,659
Segment Profit (Loss)	50,448		20,988		18,057		5,078		(6,474	)
Other Income (Expense) not included in Segment Profit (Loss)													(3,086	)
Less Equity Earnings (Losses) included in Segment Profit (Loss)													(6,659	)
Income Before Taxes, Equity Earnings and Discontinued Operations													50,675
Capital Expenditures	112,527		22,296		20,207		—		6,410		3,604		165,044
As of September 30, 2012
Property and Equipment:
Historical cost	1,119,381		488,669		517,281		43,693		21,630		29,834		2,220,488
Accumulated depreciation	(412,625	)	(120,995	)	(195,494	)	(4,151	)	(3,943	)	(8,295	)	(745,503	)
	706,756		367,674		321,787		39,542		17,687		21,539		1,474,985
Construction in progress	115,698		10,519		20,927		—		2,937		439		150,520
	822,454		378,193		342,714		39,542		20,624		21,978		1,625,505
Investments, at Equity, and Advances to 50% or Less Owned Companies	68,003		54,250		70,413		—		38,168		—		230,834
Inventories	6,249		2,435		1,533		8,810		3,329		—		22,356
Goodwill	13,367		4,345		1,852		—		37,138		—		56,702
Intangible Assets	4,557		7,996		1,544		114		5,720		—		19,931
Other current and long-term assets, excluding cash and near cash assets(3)	155,387		50,049		16,390		7,382		92,019		43,618		364,845
Segment Assets	1,070,017		497,268		434,446		55,848		196,998
Cash and near cash assets(3)													591,916
Discontinued operations													1,005,147
Total Assets													3,917,236
______________________
-1	Operating revenues includes $143.6 million of tangible product sales and operating expenses includes $137.3 million of costs of goods sold.
-2	Inventories includes raw materials of $3.6 million and work in process of $1.9 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)	9 Months Ended
	Sep. 30, 2013
Discontinued Operations [Abstract]	'
Disposal Groups, Including Discontinued Operations, Disclosure	'
	DISCONTINUED OPERATIONS
	Summarized selected operating results of the Company's discontinued operations were as follows (in thousands):
			Three Months Ended September 30,					Nine Months Ended September 30,
			2013		2012			2013			2012
	SES Business
	Operating Revenues		$	—	$	—		$	—		$	22,387
	Costs and Expenses:
	Operating		—		—			—			18,234
	Administrative and general		—		—			—			4,587
	Depreciation and amortization		—		—			—			1,428
			—		—			—			24,249
	Losses on Asset Dispositions		—		—			—			(71		)
	Operating Loss		—		—			—			(1,933		)
	Other Income (Expense), Net (including gain on sale of business)		—		—			(1,537		)	24,971
	Income Tax (Expense) Benefit		—		—			538			(4,305		)
	Equity in Earnings (Losses) of 50% or Less Owned Companies		—		—			—			302
	Net Income (Loss)		$	—	$	—		$	(999	)	$	19,035
	SEI
	Operating Revenues		$	—	$	76,296		$	—		$	392,614
	Costs and Expenses:
	Operating		—		71,789			—			382,589
	Administrative and general		—		613			—			3,749
	Depreciation and amortization		—		1			—			(3		)
			—		72,403			—			386,335
	Operating Income		—		3,893			—			6,279
	Other Income (Expense), Net (including gain on sale of business)		—		(2,545		)	(143		)	(2,540		)
	Income Tax (Expense) Benefit		—		(608		)	50			(1,711		)
	Net Income (Loss)		$	—	$	740		$	(93	)	$	2,028
	Era Group
	Operating Revenues		$	—	$	77,989		$	22,892		$	202,026
	Costs and Expenses:
	Operating		—		46,235			14,076			124,913
	Administrative and general		—		10,338			2,653			27,210
	Depreciation and amortization		—		10,937			3,875			31,031
			—		67,510			20,604			183,154
	Gains on Asset Dispositions and Impairments, Net		—		613			548			3,455
	Operating Income		—		11,092			2,836			22,327
	Other Income (Expense), Net		—		(2,819		)	(1,316		)	(5,955		)
	Income Tax (Expense)(1)		—		(2,967		)	(10,818		)	(5,737		)
	Equity in Earnings (Losses) of 50% or Less Owned Companies		—		219			65			(5,444		)
	Net Income		$	—	$	5,525		$	(9,233	)	$	5,191
	Eliminations
	Operating Revenues		$	—	$	(31,082	)	$	—		$	(86,206	)
	Costs and Expenses:
	Operating		—		(31,082		)	—			(86,204		)
	Administrative and general		—		—			—			(2		)
			—		(31,082		)	—			(86,206		)
	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, 2103. As a result, the Company has restated its results from discontinued operations for the nine months ended September 30, 2013 in the table included herein (see Note 15).

Restatement_Notes

Restatement (Notes)	9 Months Ended
	Sep. 30, 2013
Restatement [Abstract]	'
Accounting Changes and Error Corrections [Text Block]	'
	Restatement of Interim Financial Results. In late February 2014, in connection with the Company’s year-end accounting review and preparation of its year-end financial statements, an error was discovered in the accounting for taxes related to the Spin-off of Era Group. The restatement of the Company's unaudited condensed consolidated financial statements in this Amendment No. 1 to the Original Filing is solely related to this error in accounting for taxes, the principal effect of which is an increase in the net loss from discontinued operations for the nine months ended September 30, 2013 of $10.1 million (see Note 15).
	15	RESTATEMENT
	The restatement of the Company's unaudited condensed consolidated financial statements in this Amendment No. 1 to the Original Filing is solely related to an error in the accounting for taxes related to the Spin-off of Era Group, the principal effect of which is an increase in the net loss from discontinued operations for the nine months ended September 30, 2013 of $10.1 million. The following table sets forth the effect of the restatement on each impacted financial statement line item (in thousands, except share data):
			September 30, 2013			September 30, 2013
			(As Restated)			(As Previously Reported)
	Balance Sheet (unaudited):
	Other current liabilities		$	124,777		$	114,663
	Total current liabilities		224,824			214,710
	Total liabilities		1,470,991			1,460,877
	Retained earnings		1,086,874			1,096,988
	SEACOR Holdings Inc. stockholders' equity		1,355,491			1,365,605
	Total equity		1,380,733			1,390,847
			For the Nine Months Ended
			September 30, 2013			September 30, 2013
			(As Restated)			(As Previously Reported)
	Statement of Income (unaudited):
	Loss from Discontinued Operations, Net of Tax		$	(10,325	)	$	(211	)
	Net Income		28,704			38,818
	Net Income attributable to SEACOR Holdings Inc.		28,574			38,688
	Net Income (Loss) attributable to SEACOR Holdings Inc.:
	Continuing operations		$	38,799		$	38,799
	Discontinued operations		(10,225		)	(111		)
			$	28,574		$	38,688
	Basic Income (Loss) Per Common Share of SEACOR Holdings Inc.:
	Continuing operations		$	1.96		$	1.96
	Discontinued operations		(0.52		)	(0.01		)
			$	1.44		$	1.95
	Diluted Income (Loss) Per Common Share of SEACOR Holdings Inc.:
	Continuing operations		$	1.92		$	1.92
	Discontinued operations		(0.51		)	—
			$	1.41		$	1.92
	Statement of Comprehensive Income (unaudited):
	Net Income		$	28,704		$	38,818
	Comprehensive Income		28,916			39,030
	Comprehensive Income attributable to SEACOR Holdings Inc.		28,806			38,920

Basis_of_Presentation_and_Acco1

Basis of Presentation and Accounting Policy (Policy)	9 Months Ended
	Sep. 30, 2013
Nature Of Operations And Accounting Policies [Abstract]	'
Basis Of Consolidation	'
	The condensed consolidated financial information for the three and nine months ended September 30, 2013 and 2012 has been prepared by the Company and has not been audited by its independent registered public accounting firm. The condensed consolidated financial statements include the accounts of SEACOR Holdings Inc. and its consolidated subsidiaries. In the opinion of management, all adjustments (consisting of normal recurring adjustments) have been made to fairly present the Company’s financial position as of September 30, 2013, its results of operations for the three and nine months ended September 30, 2013 and 2012, its comprehensive income for the three and nine months ended September 30, 2013 and 2012, its changes in equity for the nine months ended September 30, 2013, and its cash flows for the nine months ended September 30, 2013 and 2012. Results of operations for the interim periods presented are not necessarily indicative of operating results for the full year or any future periods.
	Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States have been condensed or omitted. These condensed consolidated financial statements should be read in conjunction with the financial statements and related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.
	Unless the context otherwise indicates, any reference in this Quarterly Report on Form 10-Q to the “Company” refers to SEACOR Holdings Inc. and its consolidated subsidiaries and any reference in this Quarterly Report on Form 10-Q to “SEACOR” refers to SEACOR Holdings Inc.
Discontinued Operations, Policy	'
	Discontinued Operations. On January 31, 2013, the Company completed the spin-off ("Spin-off") of Era Group Inc. (“Era Group”), the company that operated SEACOR's Aviation Services business segment, by means of a dividend to SEACOR's stockholders of all the issued and outstanding common stock of Era Group. Era Group filed a Registration Statement on Form 10 with the Securities and Exchange Commission, describing the Spin-off, that was declared effective on January 14, 2013. Era Group is now an independent company whose common stock is listed on the New York Stock Exchange under the symbol "ERA." Discontinued operations includes the historical financial position, results of operations and cash flows of Era Group as well as the operations previously reported as discontinued in the Company's Annual Report on Form 10-K for the year ended December 31, 2012 (see Note 14).
Revenue Recognition	'
	Revenue Recognition. The Company recognizes revenue when it is realized or realizable and earned. Revenue is realized or realizable and earned when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price to the buyer is fixed or determinable, and collectability is reasonably assured. Revenue that does not meet these criteria is deferred until the criteria are met. Deferred revenues, included in other current liabilities, for the nine months ended September 30 were as follows (in thousands):
		2013				2012
	Balance at beginning of period	$	6,592			$	9,845
	Revenues deferred during the period	—				2,827
	Revenues recognized during the period	—				(7,007		)
	Balance at end of period	$	6,592			$	5,665
	As of September 30, 2013, deferred revenues of $6.6 million were related to the time charter of several offshore support vessels scheduled to be paid through the conveyance of an overriding royalty interest (the "Conveyance") in developmental oil and gas producing properties operated by a customer in the U.S. Gulf of Mexico. Payments under the Conveyance, and the timing of such payments, are contingent upon production and energy sale prices. On August 17, 2012, the customer filed a voluntary petition for Chapter 11 bankruptcy. The Company is vigorously defending its interest in connection with the bankruptcy filing; however, payments received under the Conveyance subsequent to August 17, 2012 are subject to bankruptcy court approval. The Company will continue to recognize revenues as cash is received and approved by the bankruptcy court or earlier should future collection become reasonably assured. All costs and expenses related to these charters were recognized as incurred.
Reclassifications	'
	Reclassifications. Certain reclassifications of prior period information have been made to conform to the presentation of the current period information. These reclassifications had no effect on net income as previously reported.
Accounting Changes and Error Corrections [Text Block]	'
	Restatement of Interim Financial Results. In late February 2014, in connection with the Company’s year-end accounting review and preparation of its year-end financial statements, an error was discovered in the accounting for taxes related to the Spin-off of Era Group. The restatement of the Company's unaudited condensed consolidated financial statements in this Amendment No. 1 to the Original Filing is solely related to this error in accounting for taxes, the principal effect of which is an increase in the net loss from discontinued operations for the nine months ended September 30, 2013 of $10.1 million (see Note 15).
	15	RESTATEMENT
	The restatement of the Company's unaudited condensed consolidated financial statements in this Amendment No. 1 to the Original Filing is solely related to an error in the accounting for taxes related to the Spin-off of Era Group, the principal effect of which is an increase in the net loss from discontinued operations for the nine months ended September 30, 2013 of $10.1 million. The following table sets forth the effect of the restatement on each impacted financial statement line item (in thousands, except share data):
			September 30, 2013				September 30, 2013
			(As Restated)				(As Previously Reported)
	Balance Sheet (unaudited):
	Other current liabilities		$	124,777			$	114,663
	Total current liabilities		224,824				214,710
	Total liabilities		1,470,991				1,460,877
	Retained earnings		1,086,874				1,096,988
	SEACOR Holdings Inc. stockholders' equity		1,355,491				1,365,605
	Total equity		1,380,733				1,390,847
			For the Nine Months Ended
			September 30, 2013				September 30, 2013
			(As Restated)				(As Previously Reported)
	Statement of Income (unaudited):
	Loss from Discontinued Operations, Net of Tax		$	(10,325	)		$	(211	)
	Net Income		28,704				38,818
	Net Income attributable to SEACOR Holdings Inc.		28,574				38,688
	Net Income (Loss) attributable to SEACOR Holdings Inc.:
	Continuing operations		$	38,799			$	38,799
	Discontinued operations		(10,225		)		(111		)
			$	28,574			$	38,688
	Basic Income (Loss) Per Common Share of SEACOR Holdings Inc.:
	Continuing operations		$	1.96			$	1.96
	Discontinued operations		(0.52		)		(0.01		)
			$	1.44			$	1.95
	Diluted Income (Loss) Per Common Share of SEACOR Holdings Inc.:
	Continuing operations		$	1.92			$	1.92
	Discontinued operations		(0.51		)		—
			$	1.41			$	1.92
	Statement of Comprehensive Income (unaudited):
	Net Income		$	28,704			$	38,818
	Comprehensive Income		28,916				39,030
	Comprehensive Income attributable to SEACOR Holdings Inc.		28,806				38,920

Basis_of_Presentation_and_Acco2

Basis of Presentation and Accounting Policy (Tables)	9 Months Ended
	Sep. 30, 2013
Nature Of Operations And Accounting Policies [Abstract]	'
Deferred Revenues Included In Other Current Liabilities	'
	Deferred revenues, included in other current liabilities, for the nine months ended September 30 were as follows (in thousands):
		2013				2012
	Balance at beginning of period	$	6,592			$	9,845
	Revenues deferred during the period	—				2,827
	Revenues recognized during the period	—				(7,007		)
	Balance at end of period	$	6,592			$	5,665
Comprehensive Income (Loss) Note	'
	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)		(468		)		825			—			357			(20		)	—			$	337
	Income tax (expense) benefit		164				(289		)	—			(125		)	—			—			(125		)
	Nine months ended September 30, 2013		$	(1,597	)		$	(196	)	$	(16	)	$	(1,809	)	$	301		$	(10	)	$	212

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	'
	The Company’s financial assets and liabilities as of September 30, 2013 that are measured at fair value on a recurring basis were as follows (in thousands):
		Level 1			Level 2			Level 3
	ASSETS
	Marketable securities(1)	$	25,660		$	—		$	—
	Derivative instruments (included in other receivables)	177			5,238			—
	Construction reserve funds and Title XI reserve funds	229,021			—			—
	LIABILITIES
	Short sale of marketable securities (included in other current liabilities)	8,837			—			—
	Derivative instruments (included in other current liabilities)	384			3,299			—
	______________________
	-1	Marketable security gains (losses), net include unrealized losses of $1.2 million and unrealized losses of $0.4 million for the three months ended September 30, 2013 and 2012, respectively, related to marketable security positions held by the Company as of September 30, 2013.
Estimated Fair Value Of Other Financial Assets And Liabilities	'
	The estimated fair values of the Company’s other financial assets and liabilities as of September 30, 2013 were as follows (in thousands):
					Estimated Fair Value
		Carrying			Level 1			Level 2			Level 3
		Amount
	ASSETS
	Cash, cash equivalents and restricted cash	$	353,660		$	353,660		$	—		$	—
	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	26,462			see below
	assets)
	LIABILITIES
	Long-term debt, including current portion(1)	702,179			—			838,218			—
	______________________
	-1	The estimated fair value includes the conversion option on the Company's 2.5% Convertible Notes.
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis	'
	The Company’s non-financial assets and liabilities that were measured at fair value during the nine months ended September 30, 2013 were as follows (in thousands):
			Level 1			Level 2			Level 3
	ASSETS
	Long-lived assets under construction(1)		$	17,494		$	—		$	—
	Investment in C-Lift LLC(2)		—			13,290			—
	Contribution of non-cash consideration to Dorian LPG Ltd. (3)		—			14,989			—
	______________________
	-1	During the nine months ended September 30, 2013, the Company recognized impairment charges of $3.0 million related to two of Shipping Services' harbor tugs while under construction, which were sold and leased back upon their completion (see Note 5).
	-2	During the nine months ended September 30, 2013, the Company marked its equity investment in C-Lift LLC ("C-Lift") to fair value following its acquisition of a controlling interest (see Note 4). The investment's fair value was determined based on the Company's purchase price of the acquired interest.
	-3	During the nine months ended September 30, 2013, the Company marked to fair value the non-cash consideration contributed to Dorian LPG Ltd. ("Dorian") in exchange for an equity investment (see Note 6). The fair value was determined based on the value of the equity investment the Company received.

Derivative_Instruments_And_Hed1

Derivative Instruments And Hedging Strategies (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative [Line Items]	'
Fair Values Of Derivative Instruments	'
	The fair values of the Company’s derivative instruments as of September 30, 2013 were as follows (in thousands):
		Derivative			Derivative
		Asset			Liability
	Options on equities and equity indices	$	269		$	—
	Forward currency exchange, option and future contracts	197			215
	Interest rate swap agreements	—			3,071
	Commodity swap, option and future contracts:
	Exchange traded	71			383
	Non-exchange traded	4,878			14
		$	5,415		$	3,683
Cash Flow Hedging [Member]	'
Derivative [Line Items]	'
Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments	'
	The Company recognized gains (losses) on derivative instruments designated as cash flow hedges for the nine months ended September 30 as follows (in thousands):
		2013			2012
	Interest rate swap agreements, effective portion in other comprehensive income (loss)	$	572		$	(1,290	)
	Interest rate swap agreements, ineffective portion in derivative losses, net	—			(56		)
		$	572		$	(1,346	)
Not Designated as Hedging Instrument [Member]	'
Derivative [Line Items]	'
Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments	'
	The Company recognized gains (losses) on derivative instruments not designated as hedging instruments in derivative losses, net for the nine months ended September 30 as follows (in thousands):
		2013			2012
	Options on equities and equity indices	$	(4,132	)	$	(734	)
	Forward currency exchange, option and future contracts	(439		)	884
	Interest rate swap agreements	253			(1,641		)
	Commodity swap, option and future contracts:
	Exchange traded	368			(2,847		)
	Non-exchange traded	715			1,960
		$	(3,235	)	$	(2,378	)

Business_Acquisitions_Tables

Business Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]	'
Allocation Of Purchase Price For Business Acquisitions	'
	The following table summarizes the allocation of the purchase price for the Company’s business acquisitions during the nine months ended September 30, 2013 (in thousands):
	Trade and other receivables	$	3,250
	Other current assets	32
	Investments, at Equity, and Advances to 50% or Less Owned Companies	(13,290		)
	Property and Equipment	43,521
	Intangible Assets	1,599
	Accounts payable	(264		)
	Other current liabilities	(1,640		)
	Long-Term Debt	(22,668		)
	Purchase price(1)	$	10,540
	______________________
	-1	Purchase price is net of cash acquired of $2.2 million.

Equipment_Acquisitions_Disposi1

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies (Tables)	9 Months Ended
	Sep. 30, 2013
Equipment Acquisitions, Dispositions And Depreciation And Impairment Policies [Abstract]	'
Schedule Of Deferred Gain Activity	'
	Deferred gain activity related to these transactions for the nine months ended September 30 was as follows (in thousands):
		2013			2012
	Balance at beginning of period	$	111,514		$	117,192
	Deferred gains arising from asset sales	14,609			7,280
	Amortization of deferred gains included in operating expenses as a reduction to rental expense	(7,707		)	(13,573		)
	Amortization of deferred gains included in gains on asset dispositions and impairments, net	(2,146		)	(7,872		)
	Balance at end of period	$	116,270		$	103,027
Schedule of Estimated Useful Life of Newly Acquired Equipment	'
	As of September 30, 2013, the estimated useful life (in years) of each of the Company’s major categories of new equipment was as follows:
	Offshore support vessels (excluding wind farm utility)	20
	Wind farm utility vessels	10
	Inland river dry cargo and deck barges	20
	Inland river liquid tank barges	25
	Inland river towboats	25
	U.S.-flag product tankers	25
	RORO(1) vessels	20
	Harbor tugs	25
	Ocean liquid tank barges	25
	Terminal and manufacturing facilities	20
	______________________
	-1	Roll on/Roll off ("RORO").

Earnings_Per_Common_Share_of_S1

Earnings Per Common Share of SEACOR (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Common Share of SEACOR [Abstract]	'
Schedule of Weighted Average Number of Shares	'
	Computations of basic and diluted earnings per common share of SEACOR were as follows (in thousands, except share data):
		Three Months Ended September 30,					Nine Months Ended September 30,
		Net Income Attributable to SEACOR		Average O/S Shares	Per Share		Net Income Attributable to SEACOR		Average O/S Shares	Per Share
							(As Restated)			(As Restated)
	2013
	Basic Weighted Average Common Shares Outstanding	$	30,291	19,964,695	$	1.52	$	28,574	19,843,778	$	1.44
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—		436,364			—		354,671
	Convertible Notes(2)	3,086		4,200,525			—		—
	Diluted Weighted Average Common Shares Outstanding	$	33,377	24,601,584	$	1.36	$	28,574	20,198,449	$	1.41
		Three Months Ended September 30,					Nine Months Ended September 30,
		Net Income Attributable to SEACOR		Average O/S Shares	Per Share		Net Income Attributable to SEACOR		Average O/S Shares	Per Share
	2012
	Basic Weighted Average Common Shares Outstanding	$	16,102	20,432,997	$	0.79	$	63,839	20,512,118	$	3.11
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—		307,459			—		326,350
	Diluted Weighted Average Common Shares Outstanding	$	16,102	20,740,456	$	0.78	$	63,839	20,838,468	$	3.06
	______________________
	-1	For the three months ended September 30, 2013 and 2012, diluted earnings per common share of SEACOR excluded 115,832 and 655,168 of certain share awards, respectively, as the effect of their inclusion in the computation would be anti-dilutive. For the nine months ended September 30, 2013 and 2012, diluted earnings per share of SEACOR excluded 303,313 and 555,768 of certain share awards, respectively, as the effect of their inclusion in the computation would be anti-dilutive.
	-2	For the nine months ended September 30, 2013, diluted earnings per common share of SEACOR excluded 4,200,525 common shares issuable pursuant to the Company's 2.5% Convertible Senior Notes as the effect of their inclusion in the computation would be anti-dilutive.

Share_Based_Compensation_Table

Share Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Share Based Compensation Plans	'
	Transactions in connection with the Company’s share based compensation plans during the nine months ended September 30, 2013 were as follows:
	Director stock awards granted	2,000
	Employee Stock Purchase Plan (“ESPP”) shares issued	31,586
	Restricted stock awards granted	148,300
	Restricted stock awards canceled	18,000
	Shares released from Deferred Compensation Plan	1,692
	Stock Option Activities:
	Outstanding as of December 31, 2012	1,281,821
	Granted(1)	480,762
	Exercised	(278,354	)
	Forfeited	(800	)
	Expired	(1,576	)
	Outstanding as of September 30, 2013	1,481,853
	Shares available for future grants and ESPP purchases as of September 30, 2013	558,145
	______________________
	-1	During the nine months ended September 30, 2013, the Company granted 318,012 stock options to existing option holders under make-whole provisions upon the Spin-off of Era Group.

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Operating Results, Capital Expenditures And Assets By Reporting Segment	'
	The following tables summarize the operating results, capital expenditures and assets of the Company's reportable segments.
		Offshore		Inland		Shipping		Ethanol and		Other		Corporate		Total
		Marine		River		Services		Industrial		$’000		and		$’000
		Services		Services		$’000		Alcohol				Eliminations
		$’000		$’000				$’000				$’000
	For the three months ended
	30-Sep-13
	Operating Revenues:
	External customers	156,173		51,950		48,200		52,580		27,881		—		336,784
	Intersegment	25		792		—		—		—		(817	)	—
		156,198		52,742		48,200		52,580		27,881		(817	)	336,784
	Costs and Expenses:
	Operating	95,113		38,473		28,215		52,390		26,141		(792	)	239,540
	Administrative and general	14,132		3,431		5,133		428		1,429		6,910		31,463
	Depreciation and amortization	16,470		6,869		7,841		1,489		92		742		33,503
		125,715		48,773		41,189		54,307		27,662		6,860		304,506
	Gains on Asset Dispositions	15,343		783		3,104		—		—		—		19,230
	Operating Income (Loss)	45,826		4,752		10,115		(1,727	)	219		(7,677	)	51,508
	Other Income (Expense):
	Derivative gains (losses), net	32		—		—		1,129		(380	)	(1,084	)	(303	)
	Foreign currency (gains) losses, net	1,937		(89	)	6		—		15		361		2,230
	Other, net	—		—		540		—		(3	)	(60	)	477
	Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,527		80		(1,413	)	—		36		—		230
	Segment Profit (Loss)	49,322		4,743		9,248		(598	)	(113	)
	Other Income (Expense) not included in Segment Profit (Loss)													(7,389	)
	Less Equity Earnings (Losses) included in Segment Profit (Loss)													(230	)
	Income Before Taxes, Equity Earnings and Discontinued Operations													46,523
		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 nine months ended
	30-Sep-13
	Operating Revenues:
	External customers	418,815		148,153		142,779		146,807		62,857		—		919,411
	Intersegment	77		2,023		—		—		—		(2,100	)	—
		418,892		150,176		142,779		146,807		62,857		(2,100	)	919,411
	Costs and Expenses:
	Operating	282,725		110,055		84,383		145,837		59,589		(2,023	)	680,566
	Administrative and general	43,194		11,376		16,434		1,566		4,408		24,848		101,826
	Depreciation and amortization	49,217		21,031		23,545		4,467		287		2,287		100,834
		375,136		142,462		124,362		151,870		64,284		25,112		883,226
	Gains on Asset Dispositions	25,577		5,776		149		—		1,907		141		33,550
	and Impairments, Net
	Operating Income (Loss)	69,333		13,490		18,566		(5,063	)	480		(27,071	)	69,735
	Other Income (Expense):
	Derivative gains (losses), net	357		—		—		1,641		12		(5,245	)	(3,235	)
	Foreign currency losses, net	(2,160	)	(7	)	(9	)	—		(321	)	(200	)	(2,697	)
	Other, net	11		—		742		—		51		(129	)	675
	Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	10,534		(2,306	)	(3,321	)	—		2,164		—		7,071
	Segment Profit (Loss)	78,075		11,177		15,978		(3,422	)	2,386
	Other Income (Expense) not included in Segment Profit (Loss)													(11,214	)
	Less Equity Earnings (Losses) included in Segment Profit (Loss)													(7,071	)
	Income Before Taxes, Equity Earnings and Discontinued Operations													53,264
	Capital Expenditures	85,324		22,138		36,218		656		384		1,763		146,483
	As of September 30, 2013
	Property and Equipment:
	Historical cost	1,160,334		473,349		495,877		43,812		3,992		30,951		2,208,315
	Accumulated depreciation	(457,454	)	(140,747	)	(216,270	)	(10,081	)	(600	)	(10,452	)	(835,604	)
		702,880		332,602		279,607		33,731		3,392		20,499		1,372,711
	Construction in progress	95,552		23,814		7,323		632		2,119		41		129,481
		798,432		356,416		286,930		34,363		5,511		20,540		1,502,192
	Investments, at Equity, and Advances to 50% or Less Owned Companies	99,191		57,445		123,354		—		85,901		—		365,891
Inventories	6,187		2,277		1,794		12,856		2,328		—		25,442
Goodwill	13,367		2,759		1,852		—		—		—		17,978
Intangible Assets	4,116		8,049		1,002		29		387		—		13,583
Other current and long-term assets, excluding cash and near cash assets(3)	160,248		45,881		19,480		6,765		62,863		23,060		318,297
Segment Assets	1,081,541		472,827		434,412		54,013		156,990
Cash and near cash assets(3)													608,341
Total Assets													2,851,724
______________________
-1	Operating revenues includes $144.2 million of tangible product sales and operating expenses includes $143.3 million of costs of goods sold.
-2	Inventories includes raw materials of $2.7 million and work in process of $2.1 million.
-3	Cash and near cash assets includes cash, cash equivalents, restricted cash, marketable securities, construction reserve funds and Title XI reserve funds.
	Offshore		Inland		Shipping		Ethanol and		Other		Corporate		Total
	Marine		River		Services		Industrial		$’000		and		$’000
	Services		Services		$’000		Alcohol				Eliminations
	$’000		$’000				$’000				$’000
For the three months ended
September 30, 2012
Operating Revenues:
External customers	134,296		53,293		45,157		47,813		58,296		—		338,855
Intersegment	26		—		—		—		40		(66	)	—
	134,322		53,293		45,157		47,813		58,336		(66	)	338,855
Costs and Expenses:
Operating	88,842		38,320		28,089		45,472		53,287		(5	)	254,005
Administrative and general	14,795		3,480		6,567		545		5,635		8,487		39,509
Depreciation and amortization	16,051		7,335		7,776		1,578		753		854		34,347
	119,688		49,135		42,432		47,595		59,675		9,336		327,861
Gains (Losses) on Asset Dispositions and Impairments, Net	6,585		3,503		145		—		(1,169	)	—		9,064
Operating Income (Loss)	21,219		7,661		2,870		218		(2,508	)	(9,402	)	20,058
Other Income (Expense):
Derivative losses, net	—		—		—		(1,035	)	(838	)	(157	)	(2,030	)
Foreign currency gains (losses), net	717		33		8		—		(25	)	295		1,028
Other, net	—		—		7,145		—		—		(47	)	7,098
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,238		(2,227	)	(551	)	—		243		—		(1,297	)
Segment Profit (Loss)	23,174		5,467		9,472		(817	)	(3,128	)
Other Income (Expense) not included in Segment Profit (Loss)													(7,916	)
Less Equity Earnings (Losses) included in Segment Profit (Loss)													1,297
Income Before Taxes, Equity Earnings and Discontinued Operations													18,238
	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 nine months ended
30-Sep-12
Operating Revenues:
External customers	378,606		160,085		133,606		146,370		127,262		—		945,929
Intersegment	78		—		108		—		75		(261	)	—
	378,684		160,085		133,714		146,370		127,337		(261	)	945,929
Costs and Expenses:
Operating	258,266		110,966		83,875		140,078		113,930		(146	)	706,969
Administrative and general	39,797		11,235		16,939		1,404		16,332		25,094		110,801
Depreciation and amortization	44,792		21,586		22,755		4,208		2,153		1,775		97,269
	342,855		143,787		123,569		145,690		132,415		26,723		915,039
Gains (Losses) on Asset Dispositions and Impairments, Net	9,054		6,288		2,005		—		(1,164	)	—		16,183
Operating Income (Loss)	44,883		22,586		12,150		680		(6,242	)	(26,984	)	47,073
Other Income (Expense):
Derivative gains (losses), net	—		—		—		(1,756	)	261		(939	)	(2,434	)
Foreign currency gains (losses), net	1,486		(60	)	17		—		(10	)	232		1,665
Other, net	11		—		7,432		—		—		14		7,457
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	4,068		(1,538	)	(1,542	)	6,154		(483	)	—		6,659
Segment Profit (Loss)	50,448		20,988		18,057		5,078		(6,474	)
Other Income (Expense) not included in Segment Profit (Loss)													(3,086	)
Less Equity Earnings (Losses) included in Segment Profit (Loss)													(6,659	)
Income Before Taxes, Equity Earnings and Discontinued Operations													50,675
Capital Expenditures	112,527		22,296		20,207		—		6,410		3,604		165,044
As of September 30, 2012
Property and Equipment:
Historical cost	1,119,381		488,669		517,281		43,693		21,630		29,834		2,220,488
Accumulated depreciation	(412,625	)	(120,995	)	(195,494	)	(4,151	)	(3,943	)	(8,295	)	(745,503	)
	706,756		367,674		321,787		39,542		17,687		21,539		1,474,985
Construction in progress	115,698		10,519		20,927		—		2,937		439		150,520
	822,454		378,193		342,714		39,542		20,624		21,978		1,625,505
Investments, at Equity, and Advances to 50% or Less Owned Companies	68,003		54,250		70,413		—		38,168		—		230,834
Inventories	6,249		2,435		1,533		8,810		3,329		—		22,356
Goodwill	13,367		4,345		1,852		—		37,138		—		56,702
Intangible Assets	4,557		7,996		1,544		114		5,720		—		19,931
Other current and long-term assets, excluding cash and near cash assets(3)	155,387		50,049		16,390		7,382		92,019		43,618		364,845
Segment Assets	1,070,017		497,268		434,446		55,848		196,998
Cash and near cash assets(3)													591,916
Discontinued operations													1,005,147
Total Assets													3,917,236
______________________
-1	Operating revenues includes $143.6 million of tangible product sales and operating expenses includes $137.3 million of costs of goods sold.
-2	Inventories includes raw materials of $3.6 million and work in process of $1.9 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)	9 Months Ended
	Sep. 30, 2013
Discontinued Operations [Abstract]	'
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	'
	Summarized selected operating results of the Company's discontinued operations were as follows (in thousands):
			Three Months Ended September 30,					Nine Months Ended September 30,
			2013		2012			2013			2012
	SES Business
	Operating Revenues		$	—	$	—		$	—		$	22,387
	Costs and Expenses:
	Operating		—		—			—			18,234
	Administrative and general		—		—			—			4,587
	Depreciation and amortization		—		—			—			1,428
			—		—			—			24,249
	Losses on Asset Dispositions		—		—			—			(71		)
	Operating Loss		—		—			—			(1,933		)
	Other Income (Expense), Net (including gain on sale of business)		—		—			(1,537		)	24,971
	Income Tax (Expense) Benefit		—		—			538			(4,305		)
	Equity in Earnings (Losses) of 50% or Less Owned Companies		—		—			—			302
	Net Income (Loss)		$	—	$	—		$	(999	)	$	19,035
	SEI
	Operating Revenues		$	—	$	76,296		$	—		$	392,614
	Costs and Expenses:
	Operating		—		71,789			—			382,589
	Administrative and general		—		613			—			3,749
	Depreciation and amortization		—		1			—			(3		)
			—		72,403			—			386,335
	Operating Income		—		3,893			—			6,279
	Other Income (Expense), Net (including gain on sale of business)		—		(2,545		)	(143		)	(2,540		)
	Income Tax (Expense) Benefit		—		(608		)	50			(1,711		)
	Net Income (Loss)		$	—	$	740		$	(93	)	$	2,028
	Era Group
	Operating Revenues		$	—	$	77,989		$	22,892		$	202,026
	Costs and Expenses:
	Operating		—		46,235			14,076			124,913
	Administrative and general		—		10,338			2,653			27,210
	Depreciation and amortization		—		10,937			3,875			31,031
			—		67,510			20,604			183,154
	Gains on Asset Dispositions and Impairments, Net		—		613			548			3,455
	Operating Income		—		11,092			2,836			22,327
	Other Income (Expense), Net		—		(2,819		)	(1,316		)	(5,955		)
	Income Tax (Expense)(1)		—		(2,967		)	(10,818		)	(5,737		)
	Equity in Earnings (Losses) of 50% or Less Owned Companies		—		219			65			(5,444		)
	Net Income		$	—	$	5,525		$	(9,233	)	$	5,191
	Eliminations
	Operating Revenues		$	—	$	(31,082	)	$	—		$	(86,206	)
	Costs and Expenses:
	Operating		—		(31,082		)	—			(86,204		)
	Administrative and general		—		—			—			(2		)
			—		(31,082		)	—			(86,206		)
	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, 2103. As a result, the Company has restated its results from discontinued operations for the nine months ended September 30, 2013 in the table included herein (see Note 15).

Restatement_Tables

Restatement (Tables)	9 Months Ended
	Sep. 30, 2013
Restatement [Abstract]	'
Restatement to Prior Year Income [Table Text Block]	'
	g table sets forth the effect of the restatement on each impacted financial statement line item (in thousands, except share data):
		September 30, 2013			September 30, 2013
		(As Restated)			(As Previously Reported)
	Balance Sheet (unaudited):
	Other current liabilities	$	124,777		$	114,663
	Total current liabilities	224,824			214,710
	Total liabilities	1,470,991			1,460,877
	Retained earnings	1,086,874			1,096,988
	SEACOR Holdings Inc. stockholders' equity	1,355,491			1,365,605
	Total equity	1,380,733			1,390,847
		For the Nine Months Ended
		September 30, 2013			September 30, 2013
		(As Restated)			(As Previously Reported)
	Statement of Income (unaudited):
	Loss from Discontinued Operations, Net of Tax	$	(10,325	)	$	(211	)
	Net Income	28,704			38,818
	Net Income attributable to SEACOR Holdings Inc.	28,574			38,688
	Net Income (Loss) attributable to SEACOR Holdings Inc.:
	Continuing operations	$	38,799		$	38,799
	Discontinued operations	(10,225		)	(111		)
		$	28,574		$	38,688
	Basic Income (Loss) Per Common Share of SEACOR Holdings Inc.:
	Continuing operations	$	1.96		$	1.96
	Discontinued operations	(0.52		)	(0.01		)
		$	1.44		$	1.95
	Diluted Income (Loss) Per Common Share of SEACOR Holdings Inc.:
	Continuing operations	$	1.92		$	1.92
	Discontinued operations	(0.51		)	—
		$	1.41		$	1.92
	Statement of Comprehensive Income (unaudited):
	Net Income	$	28,704		$	38,818
	Comprehensive Income	28,916			39,030
	Comprehensive Income attributable to SEACOR Holdings Inc.	28,806			38,920

Basis_of_Presentation_and_Acco3

Basis of Presentation and Accounting Policy (Narrative) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2013
					Offshore Marine Services [Member]	Era Group [Member]	Era Group [Member]
Nature of Operations and Accounting Policies [Line Items]	'	'	'	'	'	'	'
Liability for Uncertain Tax Positions, Current	'	'	'	'	'	$10,100,000	$10,100,000
Deferred Revenue	$6,592,000	$6,592,000	$5,665,000	$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 $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Nature Of Operations And Accounting Policies [Abstract]	'	'
Balance at beginning of period	$6,592	$9,845
Revenues deferred during the period	0	2,827
Revenues recognized during the period	0	-7,007
Balance at end of period	$6,592	$5,665

Basis_of_Presentation_and_Acco5

Basis of Presentation and Accounting Policy Accumulated Other Comprehensive Income (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax	($1,809)	'	($1,809)	'	($1,986)
Stockholders' Equity Note, Spinoff Transaction	'	'	-415,371	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	'	'	357	'	'
Other Comprehensive Income (Loss), before Tax	4,177	3,656	337	7,085	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	'	'	-125	'	'
Income tax expense	1,311	1,200	125	2,345	'
Other Comprehensive Income (Loss), Net of Tax	2,866	2,456	212	4,740	'
Accumulated Translation Adjustment [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	-1,597	'	-1,597	'	-1,238
Stockholders' Equity Note, Spinoff Transaction	'	'	-55	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	'	'	-468	'	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	'	'	164	'	'
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	-196	'	-196	'	-732
Stockholders' Equity Note, Spinoff Transaction	'	'	0	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	'	'	825	'	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	'	'	-289	'	'
Other Postretirement Benefit Plans, Defined Benefit [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	-16	'	-16	'	-16
Stockholders' Equity Note, Spinoff Transaction	'	'	0	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	'	'	0	'	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	'	'	0	'	'
Non-Controlling Interests In Subsidiaries [Member]	'	'	'	'	'
Stockholders' Equity Note, Spinoff Transaction	'	'	-107	'	'
Other Comprehensive Income (Loss), Net of Tax	'	'	-20	'	'
Non-Controlling Interests In Subsidiaries [Member] | Accumulated Translation Adjustment [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	301	'	301	'	321
Stockholders' Equity Note, Spinoff Transaction	'	'	0	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Noncontrolling Interest	'	'	-20	'	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest	'	'	0	'	'
Non-Controlling Interests In Subsidiaries [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	-10	'	-10	'	-10
Stockholders' Equity Note, Spinoff Transaction	'	'	0	'	'
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Noncontrolling Interest	'	'	0	'	'
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest	'	'	0	'	'
Accumulated Other Comprehensive Income (Loss) [Member]	'	'	'	'	'
Stockholders' Equity Note, Spinoff Transaction	'	'	-55	'	'
Other Comprehensive Income (Loss), Net of Tax	'	'	$232	'	'

Fair_Value_Measurements_Financ

Fair Value Measurements (Financial Assets And Liabilities Measured At Fair Value On Recurring Basis) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Construction Reserve Funds & Title XI Reserve Funds	$229,021,000	'	$229,021,000	'	$195,629,000
Marketable security gains (losses), net include losses	-1,200,000	-400,000	9,400,000	-400,000	'
Fair Value, Inputs, Level 1 [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Marketable securities	25,660,000	'	25,660,000	'	'
Derivative instruments (included in other receivables)	177,000	'	177,000	'	'
Construction Reserve Funds & Title XI Reserve Funds	229,021,000	'	229,021,000	'	'
Short sales of marketable securities	8,837,000	'	8,837,000	'	'
Derivative instruments (included in other current liabilities)	384,000	'	384,000	'	'
Fair Value, Inputs, Level 2 [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Marketable securities	0	'	0	'	'
Derivative instruments (included in other receivables)	5,238,000	'	5,238,000	'	'
Construction reserve funds and Title XI reserve funds	0	'	0	'	'
Short sales of marketable securities	0	'	0	'	'
Derivative instruments (included in other current liabilities)	3,299,000	'	3,299,000	'	'
Fair Value, Inputs, Level 3 [Member]	'	'	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'
Marketable securities	0	'	0	'	'
Derivative instruments (included in other receivables)	0	'	0	'	'
Construction reserve funds and Title XI reserve funds	0	'	0	'	'
Short sales of marketable securities	0	'	0	'	'
Derivative instruments (included in other current liabilities)	$0	'	$0	'	'

Fair_Value_Measurements_Estima

Fair Value Measurements (Estimated Fair Value Of Other Financial Assets And Liabilities) (Details) (USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Cash, cash equivalents and restricted cash, Carrying Amount	$353,660
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)	26,462
Long-term debt, including current portion, Carrying Amount	702,179
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	353,660
Debt Instrument, Fair Value Disclosure	0
Fair Value, Inputs, Level 2 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Cash and Cash Equivalents, Fair Value Disclosure	0
Debt Instrument, Fair Value Disclosure	838,218
Fair Value, Inputs, Level 3 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Cash and Cash Equivalents, Fair Value Disclosure	0
Debt Instrument, Fair Value Disclosure	$0
Two Point Five Percentage Convertible Notes [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	2.50%

Fair_Value_Measurements_NonFin

Fair Value Measurements (Non-Financial Assets And Liabilities Measured At Fair Value) (Details) (USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Fair Value, Inputs, Level 1 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Assets Held-for-sale, Long Lived	$17,494
Fair Value, Inputs, Level 2 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Assets Held-for-sale, Long Lived	0
Fair Value, Inputs, Level 3 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Assets Held-for-sale, Long Lived	0
C Lift L L C [Member] | Fair Value, Inputs, Level 1 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Equity Method Investments, Fair Value Disclosure	0
C Lift L L C [Member] | Fair Value, Inputs, Level 2 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Equity Method Investments, Fair Value Disclosure	13,290
C Lift L L C [Member] | Fair Value, Inputs, Level 3 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Equity Method Investments, Fair Value Disclosure	0
Dorian LPG [Member] | Fair Value, Inputs, Level 1 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Equity Method Investments, Fair Value Disclosure	0
Dorian LPG [Member] | Fair Value, Inputs, Level 2 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Equity Method Investments, Fair Value Disclosure	14,989
Dorian LPG [Member] | Fair Value, Inputs, Level 3 [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Equity Method Investments, Fair Value Disclosure	$0

Derivative_Instruments_And_Hed2

Derivative Instruments And Hedging Strategies (Narrative) (Details)	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
In Millions, unless otherwise specified	Seajon [Member]	Not Designated as Hedging Instrument [Member]	Not Designated as Hedging Instrument [Member]	Not Designated as Hedging Instrument [Member]	Not Designated as Hedging Instrument [Member]
	Cash Flow Hedging [Member]	Interest Rate Swap Agreements [Member]	Windcat Acquisition [Member]	Windcat Acquisition [Member]	Dynamic Offshore Drilling Ltd [Member]
	USD ($)	USD ($)	Interest Rate Swap Agreements [Member]	Interest Rate Swap Agreements [Member]	Interest Rate Swap Agreements [Member]
			USD ($)	EUR (€)	USD ($)
Derivative [Line Items]	'	'	'	'	'
Fixed interest rate range, minimum	'	2.25%	'	'	'
Fixed interest rate range, maximum	'	3.05%	'	'	'
Derivative, Notional Amount	$37.80	$221.50	$14.80	€ 10.90	$105.60
Fixed interest rate	2.79%	'	'	'	1.30%

Derivative_Instruments_And_Hed3

Derivative Instruments And Hedging Strategies (Fair Values Of Derivative Instruments) (Details) (Not Designated as Hedging Instrument [Member], USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	$5,415
Derivative Liability	3,683
Foreign Exchange [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	197
Derivative Liability	215
Interest Rate Swap Agreements [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	0
Derivative Liability	3,071
Options On Equities And Equity Indices [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	269
Derivative Liability	0
Commodity Swap, Option And Future Contracts, Non-Exchange Traded [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	4,878
Derivative Liability	14
Commodity Contract [Member]	'
Derivative [Line Items]	'
Derivative Asset, Fair Value, Gross Asset	71
Derivative Liability	$383

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		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	$192,000	($619,000)	'	'
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax	0	1,330,000	0	1,330,000
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	'	'	572,000	-1,346,000
Interest Rate Swap Agreements [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	'	'	572,000	-1,290,000
Cash Flow Hedging [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax	'	'	0	-56,000
Dorian LPG [Member] | Cash Flow Hedging [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative, Lower Fixed Interest Rate Range	2.96%	'	2.96%	'
Derivative, Higher Fixed Interest Rate Range	5.40%	'	5.40%	'
Derivative, Notional Amount	131,700,000	'	131,700,000	'
Sea Cat Crewzer [Member] | Cash Flow Hedging [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative, Fixed Interest Rate	1.48%	'	1.48%	'
Derivative, Notional Amount	17,100,000	'	17,100,000	'
SCFCo Holdings [Member] | Cash Flow Hedging [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative, Lower Fixed Interest Rate Range	1.53%	'	1.53%	'
Derivative, Higher Fixed Interest Rate Range	4.16%	'	4.16%	'
Derivative, Notional Amount	35,400,000	'	35,400,000	'
Seajon [Member] | Cash Flow Hedging [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative, Fixed Interest Rate	2.79%	'	2.79%	'
Derivative, Notional Amount	$37,800,000	'	$37,800,000	'

Derivative_Instruments_And_Hed5

Derivative Instruments And Hedging Strategies (Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments) (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Derivative [Line Items]	'	'
Derivative gains (losses), net	($3,235,000)	($2,378,000)
Options On Equities And Equity Indices [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	-4,132,000	-734,000
Forward Currency Exchange, Option And Future Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	-439,000	884,000
Interest Rate Swap Agreements [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	253,000	-1,641,000
Commodity Contract [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	368,000	-2,847,000
Commodity Swap, Option And Future Contracts, Non-Exchange Traded [Member]	'	'
Derivative [Line Items]	'	'
Derivative gains (losses), net	715,000	1,960,000
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Notional Amount	13,000,000	'
Not Designated as Hedging Instrument [Member] | Interest Rate Swap Agreements [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Lower Fixed Interest Rate Range	2.25%	'
Derivative, Higher Fixed Interest Rate Range	3.05%	'
Derivative, Notional Amount	221,500,000	'
Not Designated as Hedging Instrument [Member] | Dorian LPG [Member] | Interest Rate Swap Agreements [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Notional Amount	$300,000	'
Derivative, Fixed Interest Rate	4.35%	'

Business_Acquisitions_Narrativ

Business Acquisitions (Narrative) (Details) (USD $)	9 Months Ended				9 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Jun. 06, 2013	Jun. 06, 2013	Sep. 30, 2012	Jun. 25, 2012	Sep. 30, 2012	Mar. 30, 2012
		C Lift L L C [Member]	C Lift L L C [Member]	C Lift L L C [Member]	Pantagro Acquisition [Member] [Member]	Pantagro Acquisition [Member] [Member]	Superior Energy Services, LLC [Member]	Superior Energy Services, LLC [Member]
				Liftboats [Member]				Liftboats [Member]
Business Acquisition [Line Items]	'	'	'	'	'	'	'	'
Business Acquisition, Percentage of Voting Interests Acquired	'	'	50.00%	'	'	'	'	'
Cash Acquired from Acquisition	$2.20	'	'	'	'	'	'	'
Payments to Acquire Businesses, Gross	'	12.7	'	'	0.2	'	142.5	'
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred	'	'	'	'	0.2	'	'	'
Equity Method Investment, Ownership Percentage	'	'	100.00%	'	'	95.00%	'	'
Business Combination, Consideration Transferred	'	'	'	'	$0.40	'	'	'
Number Of Equipments Acquired	'	'	'	2	'	'	'	18

Business_Acquisitions_Allocati

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

Equipment_Acquisitions_Disposi2

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies (Deferred Gain Activity) (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Movement in Deferred Gain Activity [Roll Forward]	'	'
Deferred Gains at Beginning of Period	$111,514	$117,192
Deferred Gain On Sale Of Equipments	14,609	7,280
Amortization Of Deferred Gains Included in Operating Expenses As A Reduction To Rental Expense	-7,707	-13,573
Amortization Of Deferred Gains Included In Gains On Asset Dispositions And Impairments, Net	-2,146	-7,872
Deferred Gains at End of Period	$116,270	$103,027

Equipment_Acquisitions_Disposi3

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies (Useful Life) (Details)	9 Months Ended
	Sep. 30, 2013
Offshore Support Vessels [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'20 years
Wind Farm Utility Vessel [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'10 years
Inland River Dry Cargo And Deck Barges [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'20 years
Inland River Liquid Tank Barges [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'25 years
Inland River Towboats [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'25 years
U.S.-flag Product Tankers [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'25 years
R O R O Vessels [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'20 years	[1]
Harbor And Offshore Tugs [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'25 years
Ocean Liquid Tank Barge [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'25 years
Terminal And Manufacturing Facilities [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful life (in years)	'20 years
[1]	Roll on/Roll off ("RORO").

Equipment_Acquisitions_Disposi4

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies (Narrative) (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Property, Plant and Equipment [Line Items]	'	'
Purchases of property and equipment	$146,483,000	$165,044,000
Sales Price Of Equipment	214,700,000	'
Proceeds from Sale of Property, Plant and Equipment, Excluding Deposits on Future Equipment Sales	205,700,000	'
Vendor Credits	200,000	'
Proceeds from disposition of property and equipment	205,735,000	14,715,000
Proceeds from Issuance of Secured Debt	8,800,000	'
Gains (Losses) on Sales of Assets	49,000,000	'
Deferred Gains on Asset Sales	14,600,000	'
Amortization Of Deferred Gains Included In Gains On Asset Dispositions And Impairments, Net	-2,146,000	-7,872,000
Offshore Support Vessels Specialty [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Number Of Equipments Delivered	2	'
Number Of Equipments Sold	3	'
Offshore Support Vessels Crew [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Number Of Equipments Sold	4	'
Offshore Support Vessels Mini Supply [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Number Of Equipments Sold	1	'
Offshore Support Vessels Supply [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Number Of Equipments Sold	1	'
Liftboats [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Number Of Equipments Delivered	2	'
Number Of Equipments Sold	5	'
Wind Farm Utility Vessel [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Number Of Equipments Delivered	3	'
Inland River Dry Cargo And Deck Barges [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Number Of Equipments Sold	16	'
Inland River Liquid Tank Barges [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Number Of Equipments Delivered	2	'
Number Of Equipments Sold	8	'
U.S.-flag Harbor Tugs [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Number Of Equipments Delivered	4	'
Number Of Equipments Sold	8	'
Asset Impairment Charges	3,000,000	'
Offshore Marine Services Joint Ventures [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Proceeds from disposition of property and equipment	83,700,000	'
Gains on Asset Dispositions and Impariments, Net [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Gains (Losses) on Sales of Assets	34,400,000	'
Amortization Of Deferred Gains Included In Gains On Asset Dispositions And Impairments, Net	$2,100,000	'
Sea-Cat Crewzer II [Member] | Offshore Support Vessels Specialty [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Number Of Equipments Sold	2	'

Investments_At_Equity_And_Adva1

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

9 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Jun. 30, 2013

Sep. 30, 2013

Jun. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Jul. 25, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Jun. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Jun. 06, 2013

OSV Partners [Member]

Sea-Cat Crewzer II [Member]

Sea-Cat Crewzer II [Member]

Mexmar [Member]

Mexmar [Member]

SCFCo Holdings [Member]

Bunge Scf Grain [Member]

Witt O'Brien's LLC [Member]

Corporate Joint Venture [Member]

Offshore Marine Services Joint Ventures [Member]

Dorian LPG [Member]

Dorian LPG [Member]

Offshore Support Vessels [Member]

Offshore Support Vessels [Member]

Offshore Support Vessels [Member]

Offshore Support Vessels [Member]

Very Large Gas Carrier [Member]

Subsequent Event [Member]

C Lift L L C [Member]

C Lift L L C [Member]

equipment

OSV Partners [Member]

Sea-Cat Crewzer II [Member]

Mexmar [Member]

equipment

Offshore Support Vessels [Member]

equipment

equipment

equipment

equipment

Schedule Of Equity Method Investments [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Equipment Operated

'

'

$6

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Partners' Capital Account, Contributions

'

'

'

'

'

'

'

'

'

'

'

'

57,000,000

'

'

'

'

'

'

'

'

'

Equity Method Investment, Ownership Percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

25.00%

'

'

'

'

'

'

'

100.00%

Equity Method Investment, Ownership Percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

50.00%

Payments to Acquire Businesses, Gross

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

12,700,000

'

Business Acquisition, Preexisting Relationship, Gain (Loss) Recognized

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,200,000

Partners' Capital Account, Contributions, Cash

'

'

1,800,000

23,000,000

'

5,900,000

'

4,000,000

'

'

500,000

'

42,100,000

'

'

'

'

'

'

'

'

'

Partners' Capital Account, Contributions, Noncash

'

'

'

'

'

'

'

'

'

'

'

'

14,900,000

'

'

'

'

'

'

'

'

'

Number Of Equipments Delivered

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

2

1

'

'

'

'

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

'

'

'

47,300,000

'

36,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payments to Acquire Machinery and Equipment

'

'

'

44,500,000

'

30,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Secured Debt

'

'

'

'

2,800,000

'

6,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Secured Debt, Repayments

'

'

'

'

'

6,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Temporary Working Capital Advances Provided during the Period

'

'

7,600,000

'

'

1,700,000

'

2,300,000

2,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Temporary Working Capital Advances Repaid during the Period

'

'

'

'

'

'

'

1,800,000

500,000

'

1,000,000

'

'

'

'

'

'

'

'

'

'

'

Outstanding Working Capital Advances At End Of Period

'

'

'

'

'

'

'

3,400,000

7,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from Equity Method Investment, Dividends or Distributions

10,642,000

77,981,000

'

'

'

'

'

'

'

1,500,000

'

6,500,000

'

'

'

'

'

'

'

'

'

'

Unrecorded Unconditional Purchase Obligation, Maximum Quantity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15

'

'

'

2

2

'

'

Guarantor Obligations, Maximum Exposure, Undiscounted

15,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Allocable Share of Uncalled Capital

$2,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Commitments_And_Contingencies_

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

Sep. 30, 2013

Jun. 08, 2011

Dec. 31, 2010

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2012

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Robins Case [Member]

Wunstell Action [Member]

Darnell Alexander [Member]

Prejean [Member]

Abney Litigation [Member]

HEPACO Litigation [Member]

Offshore Support Vessels [Member]

Inland River Liquid Tank Barges [Member]

Inland River Towboats [Member]

U.S.-flag Product Tankers [Member]

Other Machinery and Equipment [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

claim

plaintiff

claim

claim

claim

equipment

equipment

equipment

equipment

Offshore Support Vessels [Member]

Inland River Towboats [Member]

equipment

equipment

Loss Contingencies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total unfunded capital commitments

$366,500,000

'

'

'

'

'

'

$100,600,000

$1,700,000

$6,300,000

$250,500,000

$7,400,000

$39,200,000

'

'

Unrecorded Unconditional Purchase Obligation, Due within Two Years

300,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrecorded Unconditional Purchase Obligation, Maximum Quantity

'

'

'

'

'

'

'

15

2

5

2

'

'

2

1

Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year

25,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrecorded Unconditional Purchase Obligation, Due within Four Years

41,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of claims company did not attempt to dismiss

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

Additional individual civil actions filed

'

'

2

117

3

668

'

'

'

'

'

'

'

'

'

Loss Contingency, Damages Sought, Value

'

'

'

'

'

'

$20,291,178.92

'

'

'

'

'

'

'

'

Multiemployer_Pension_Plans_De

Multiemployer Pension Plans (Details)	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2013
In Millions, unless otherwise specified	American Maritime Officers Pension Plan [Member]	United Kingdom Merchant Navy Officers Pension Fund [Member]	United Kingdom Merchant Navy Officers Pension Fund [Member]
	USD ($)	USD ($)	GBP (£)
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Pension and other postretirement benefit plans, withdrawal liability	$45.60	'	'
Pension And Other Postretirement Benefit Plans, Total Funding Deficit	'	'	120
Pension and Other Postretirement Benefit Plans, Allocated Share of Funding Deficit	'	$2.70	£ 1.7

LongTerm_Debt_and_Capital_Leas1

Long-Term Debt and Capital Lease Obligations (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Debt Instrument [Line Items]	'	'
Letters of Credit Outstanding, Amount	$28,100,000	'
Repayments of Debt and Capital Lease Obligations	13,129,000	67,178,000
Net borrowings (repayments) on inventory financing arrangements	($4,183,000)	$13,368,000
Seven Point Three Seven Five Percentage Senior Notes Due Two Thousand Nineteen Member	'	'
Debt Instrument [Line Items]	'	'
Debt Instrument, Interest Rate, Stated Percentage	7.38%	'

Stock_Repurchases_Details

Stock Repurchases (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Stock Repurchases [Abstract]	'
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$100

Earnings_Per_Common_Share_of_S2

Earnings Per Common Share of SEACOR (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]	'	'	'	'
Net Income attributable to SEACOR Holdings Inc.	$30,291	$16,102	$28,574	$63,839
Net Income (Loss) Available to Common Stockholders, Diluted	33,377	16,102	28,574	63,839
Weighted Average Number of Shares Outstanding, Basic	19,964,695	20,432,997	19,843,778	20,512,118
Incremental Common Shares Attributable to Share-based Payment Arrangements	436,364	307,459	354,671	326,350
Incremental Common Shares Attributable to Conversion of Debt Securities	4,200,525	'	0	'
Weighted Average Number of Shares Outstanding, Diluted	24,601,584	20,740,456	20,198,449	20,838,468
Earnings Per Share, Basic	$1.52	$0.79	$1.44	$3.11
Earnings Per Share, Diluted	$1.36	$0.78	$1.41	$3.06
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	115,832	655,168	303,313	555,768
Two Point Five Percentage Convertible Notes [Member]	'	'	'	'
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	'	'	4,200,525	'
Equity Securities [Member]	'	'	'	'
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]	'	'	'	'
Dilutive Securities, Effect on Basic Earnings Per Share	0	0	0	0
Convertible Debt Securities [Member]	'	'	'	'
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]	'	'	'	'
Dilutive Securities, Effect on Basic Earnings Per Share	$3,086	'	$0	'
Two Point Five Percentage Convertible Notes [Member]	'	'	'	'
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	2.50%	'	2.50%	'

Share_Based_Compensation_Share

Share Based Compensation (Share Based Compensation Plans) (Details)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Director stock awards granted	2,000,000	'
Employee Stock Purchase Plan shares issued	31,586,000	'
Restricted stock awards granted	148,300,000	'
Restricted stock awards forfeited	18,000,000	'
Shares released from Deferred Compensation Plan	1,692,000	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'	'
Stock Options, Outstanding as of December 31, 2012	1,281,821,000	1,481,853,000
Stock Option, Granted	480,762,000	'
Stock Option, Exercised	278,354,000	'
Stock Option, Forfeited	800,000	'
Stock Option, Expired	1,576,000	'
Stock Options, Outstanding as of September 30, 2013	'	1,481,853,000
Shares available for future grants and ESPP purchases as of June 30, 2013	558,145,000	'
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		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	$336,784,000	$338,855,000	$919,411,000	$945,929,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Administrative and general	31,463,000	39,509,000	101,826,000	110,801,000	'
Depreciation and amortization	33,503,000	34,347,000	100,834,000	97,269,000	'
Total costs and expenses	304,506,000	327,861,000	883,226,000	915,039,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	19,230,000	9,064,000	33,550,000	16,183,000	'
Operating Income (Loss)	51,508,000	20,058,000	69,735,000	47,073,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	-303,000	-2,030,000	-3,235,000	-2,434,000	'
Foreign currency gains (losses), net	2,230,000	1,028,000	-2,697,000	1,665,000	'
Other Nonoperating Income (Expense)	477,000	7,098,000	675,000	7,457,000	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	230,000	-1,297,000	7,071,000	6,659,000	'
Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	46,523,000	18,238,000	53,264,000	50,675,000	'
Capital Expenditures	'	'	146,483,000	165,044,000	'
Property, Plant and Equipment, Gross	2,208,315,000	'	2,208,315,000	'	2,238,383,000
Accumulated depreciation	835,604,000	'	835,604,000	'	763,803,000
Property, Plant and Equipment, Net In Service	1,372,711,000	'	1,372,711,000	'	1,474,580,000
Construction in Progress, Gross	129,481,000	'	129,481,000	'	110,296,000
Net property and equipment	1,502,192,000	'	1,502,192,000	'	1,584,876,000
Inventories	25,442,000	'	25,442,000	'	25,787,000
Goodwill	17,978,000	'	17,978,000	'	17,978,000
Intangible Assets, Net	13,583,000	'	13,583,000	'	15,305,000
Total assets	2,851,724,000	3,917,236,000	2,851,724,000	3,917,236,000	3,700,794,000
Offshore Marine Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	156,173,000	134,296,000	418,815,000	378,606,000	'
Inland River Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	51,950,000	53,293,000	148,153,000	160,085,000	'
Shipping Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	48,200,000	45,157,000	142,779,000	133,606,000	'
Ethanol and Industrial Alcohol [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	52,580,000	47,813,000	146,807,000	146,370,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Sales Revenue, Goods, Net	'	'	144,200,000	143,600,000	'
Cost of Goods Sold	'	'	143,300,000	137,300,000	'
Inventory, Raw Materials	2,700,000	3,600,000	2,700,000	3,600,000	'
Inventory, Work in Process	2,100,000	1,900,000	2,100,000	1,900,000	'
Other Segments [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	27,881,000	58,296,000	62,857,000	127,262,000	'
Corporate And Eliminations [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	0	0	0	0	'
Operating Segments [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	336,784,000	338,855,000	919,411,000	945,929,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Operating Expenses	239,540,000	254,005,000	680,566,000	706,969,000	'
Administrative and general	31,463,000	39,509,000	101,826,000	110,801,000	'
Depreciation and amortization	33,503,000	34,347,000	100,834,000	97,269,000	'
Total costs and expenses	304,506,000	327,861,000	883,226,000	915,039,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	19,230,000	9,064,000	33,550,000	16,183,000	'
Operating Income (Loss)	51,508,000	20,058,000	69,735,000	47,073,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	-303,000	-2,030,000	-3,235,000	-2,434,000	'
Foreign currency gains (losses), net	2,230,000	1,028,000	-2,697,000	1,665,000	'
Other Nonoperating Income (Expense)	477,000	7,098,000	675,000	7,457,000	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	230,000	-1,297,000	7,071,000	6,659,000	'
Capital Expenditures	'	'	146,483,000	165,044,000	'
Property, Plant and Equipment, Gross	2,208,315,000	2,220,488,000	2,208,315,000	2,220,488,000	'
Accumulated depreciation	835,604,000	745,503,000	835,604,000	745,503,000	'
Property, Plant and Equipment, Net In Service	1,372,711,000	1,474,985,000	1,372,711,000	1,474,985,000	'
Construction in Progress, Gross	129,481,000	150,520,000	129,481,000	150,520,000	'
Net property and equipment	1,502,192,000	1,625,505,000	1,502,192,000	1,625,505,000	'
Investments, at Equity, and Advances to 50% or Less Owned Companies	365,891,000	230,834,000	365,891,000	230,834,000	'
Inventories	25,442,000	22,356,000	25,442,000	22,356,000	'
Goodwill	17,978,000	56,702,000	17,978,000	56,702,000	'
Intangible Assets, Net	13,583,000	19,931,000	13,583,000	19,931,000	'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	318,297,000	364,845,000	318,297,000	364,845,000	'
Operating Segments [Member] | Offshore Marine Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	156,198,000	134,322,000	418,892,000	378,684,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Operating Expenses	95,113,000	88,842,000	282,725,000	258,266,000	'
Administrative and general	14,132,000	14,795,000	43,194,000	39,797,000	'
Depreciation and amortization	16,470,000	16,051,000	49,217,000	44,792,000	'
Total costs and expenses	125,715,000	119,688,000	375,136,000	342,855,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	15,343,000	6,585,000	25,577,000	9,054,000	'
Operating Income (Loss)	45,826,000	21,219,000	69,333,000	44,883,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	32,000	0	357,000	0	'
Foreign currency gains (losses), net	1,937,000	717,000	-2,160,000	1,486,000	'
Other Nonoperating Income (Expense)	0	0	11,000	11,000	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,527,000	1,238,000	10,534,000	4,068,000	'
Segment Profit (Loss)	49,322,000	23,174,000	78,075,000	50,448,000	'
Capital Expenditures	'	'	85,324,000	112,527,000	'
Property, Plant and Equipment, Gross	1,160,334,000	1,119,381,000	1,160,334,000	1,119,381,000	'
Accumulated depreciation	457,454,000	412,625,000	457,454,000	412,625,000	'
Property, Plant and Equipment, Net In Service	702,880,000	706,756,000	702,880,000	706,756,000	'
Construction in Progress, Gross	95,552,000	115,698,000	95,552,000	115,698,000	'
Net property and equipment	798,432,000	822,454,000	798,432,000	822,454,000	'
Investments, at Equity, and Advances to 50% or Less Owned Companies	99,191,000	68,003,000	99,191,000	68,003,000	'
Inventories	6,187,000	6,249,000	6,187,000	6,249,000	'
Goodwill	13,367,000	13,367,000	13,367,000	13,367,000	'
Intangible Assets, Net	4,116,000	4,557,000	4,116,000	4,557,000	'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	160,248,000	155,387,000	160,248,000	155,387,000	'
Total assets	1,081,541,000	1,070,017,000	1,081,541,000	1,070,017,000	'
Operating Segments [Member] | Inland River Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	52,742,000	53,293,000	150,176,000	160,085,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Operating Expenses	38,473,000	38,320,000	110,055,000	110,966,000	'
Administrative and general	3,431,000	3,480,000	11,376,000	11,235,000	'
Depreciation and amortization	6,869,000	7,335,000	21,031,000	21,586,000	'
Total costs and expenses	48,773,000	49,135,000	142,462,000	143,787,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	783,000	3,503,000	5,776,000	6,288,000	'
Operating Income (Loss)	4,752,000	7,661,000	13,490,000	22,586,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	0	0	0	0	'
Foreign currency gains (losses), net	-89,000	33,000	-7,000	-60,000	'
Other Nonoperating Income (Expense)	0	0	0	0	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	80,000	-2,227,000	-2,306,000	-1,538,000	'
Segment Profit (Loss)	4,743,000	5,467,000	11,177,000	20,988,000	'
Capital Expenditures	'	'	22,138,000	22,296,000	'
Property, Plant and Equipment, Gross	473,349,000	488,669,000	473,349,000	488,669,000	'
Accumulated depreciation	140,747,000	120,995,000	140,747,000	120,995,000	'
Property, Plant and Equipment, Net In Service	332,602,000	367,674,000	332,602,000	367,674,000	'
Construction in Progress, Gross	23,814,000	10,519,000	23,814,000	10,519,000	'
Net property and equipment	356,416,000	378,193,000	356,416,000	378,193,000	'
Investments, at Equity, and Advances to 50% or Less Owned Companies	57,445,000	54,250,000	57,445,000	54,250,000	'
Inventories	2,277,000	2,435,000	2,277,000	2,435,000	'
Goodwill	2,759,000	4,345,000	2,759,000	4,345,000	'
Intangible Assets, Net	8,049,000	7,996,000	8,049,000	7,996,000	'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	45,881,000	50,049,000	45,881,000	50,049,000	'
Total assets	472,827,000	497,268,000	472,827,000	497,268,000	'
Operating Segments [Member] | Shipping Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	48,200,000	45,157,000	142,779,000	133,714,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Operating Expenses	28,215,000	28,089,000	84,383,000	83,875,000	'
Administrative and general	5,133,000	6,567,000	16,434,000	16,939,000	'
Depreciation and amortization	7,841,000	7,776,000	23,545,000	22,755,000	'
Total costs and expenses	41,189,000	42,432,000	124,362,000	123,569,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	3,104,000	145,000	149,000	2,005,000	'
Operating Income (Loss)	10,115,000	2,870,000	18,566,000	12,150,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	0	0	0	0	'
Foreign currency gains (losses), net	6,000	8,000	-9,000	17,000	'
Other Nonoperating Income (Expense)	540,000	7,145,000	742,000	7,432,000	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	-1,413,000	-551,000	-3,321,000	-1,542,000	'
Segment Profit (Loss)	9,248,000	9,472,000	15,978,000	18,057,000	'
Capital Expenditures	'	'	36,218,000	20,207,000	'
Property, Plant and Equipment, Gross	495,877,000	517,281,000	495,877,000	517,281,000	'
Accumulated depreciation	216,270,000	195,494,000	216,270,000	195,494,000	'
Property, Plant and Equipment, Net In Service	279,607,000	321,787,000	279,607,000	321,787,000	'
Construction in Progress, Gross	7,323,000	20,927,000	7,323,000	20,927,000	'
Net property and equipment	286,930,000	342,714,000	286,930,000	342,714,000	'
Investments, at Equity, and Advances to 50% or Less Owned Companies	123,354,000	70,413,000	123,354,000	70,413,000	'
Inventories	1,794,000	1,533,000	1,794,000	1,533,000	'
Goodwill	1,852,000	1,852,000	1,852,000	1,852,000	'
Intangible Assets, Net	1,002,000	1,544,000	1,002,000	1,544,000	'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	19,480,000	16,390,000	19,480,000	16,390,000	'
Total assets	434,412,000	434,446,000	434,412,000	434,446,000	'
Operating Segments [Member] | Ethanol and Industrial Alcohol [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	52,580,000	47,813,000	146,807,000	146,370,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Operating Expenses	52,390,000	45,472,000	145,837,000	140,078,000	'
Administrative and general	428,000	545,000	1,566,000	1,404,000	'
Depreciation and amortization	1,489,000	1,578,000	4,467,000	4,208,000	'
Total costs and expenses	54,307,000	47,595,000	151,870,000	145,690,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	0	0	0	'
Operating Income (Loss)	-1,727,000	218,000	-5,063,000	680,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	1,129,000	-1,035,000	1,641,000	-1,756,000	'
Foreign currency gains (losses), net	0	0	0	0	'
Other Nonoperating Income (Expense)	0	0	0	0	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	0	0	6,154,000	'
Segment Profit (Loss)	-598,000	-817,000	-3,422,000	5,078,000	'
Capital Expenditures	'	'	656,000	0	'
Property, Plant and Equipment, Gross	43,812,000	43,693,000	43,812,000	43,693,000	'
Accumulated depreciation	10,081,000	4,151,000	10,081,000	4,151,000	'
Property, Plant and Equipment, Net In Service	33,731,000	39,542,000	33,731,000	39,542,000	'
Construction in Progress, Gross	632,000	0	632,000	0	'
Net property and equipment	34,363,000	39,542,000	34,363,000	39,542,000	'
Investments, at Equity, and Advances to 50% or Less Owned Companies	0	0	0	0	'
Inventories	12,856,000	8,810,000	12,856,000	8,810,000	'
Goodwill	0	0	0	0	'
Intangible Assets, Net	29,000	114,000	29,000	114,000	'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	6,765,000	7,382,000	6,765,000	7,382,000	'
Total assets	54,013,000	55,848,000	54,013,000	55,848,000	'
Operating Segments [Member] | Other Segments [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	27,881,000	58,336,000	62,857,000	127,337,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Operating Expenses	26,141,000	53,287,000	59,589,000	113,930,000	'
Administrative and general	1,429,000	5,635,000	4,408,000	16,332,000	'
Depreciation and amortization	92,000	753,000	287,000	2,153,000	'
Total costs and expenses	27,662,000	59,675,000	64,284,000	132,415,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	-1,169,000	1,907,000	-1,164,000	'
Operating Income (Loss)	219,000	-2,508,000	480,000	-6,242,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	-380,000	-838,000	12,000	261,000	'
Foreign currency gains (losses), net	15,000	-25,000	-321,000	-10,000	'
Other Nonoperating Income (Expense)	-3,000	0	51,000	0	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	36,000	243,000	2,164,000	-483,000	'
Segment Profit (Loss)	-113,000	-3,128,000	2,386,000	-6,474,000	'
Capital Expenditures	'	'	384,000	6,410,000	'
Property, Plant and Equipment, Gross	3,992,000	21,630,000	3,992,000	21,630,000	'
Accumulated depreciation	600,000	3,943,000	600,000	3,943,000	'
Property, Plant and Equipment, Net In Service	3,392,000	17,687,000	3,392,000	17,687,000	'
Construction in Progress, Gross	2,119,000	2,937,000	2,119,000	2,937,000	'
Net property and equipment	5,511,000	20,624,000	5,511,000	20,624,000	'
Investments, at Equity, and Advances to 50% or Less Owned Companies	85,901,000	38,168,000	85,901,000	38,168,000	'
Inventories	2,328,000	3,329,000	2,328,000	3,329,000	'
Goodwill	0	37,138,000	0	37,138,000	'
Intangible Assets, Net	387,000	5,720,000	387,000	5,720,000	'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	62,863,000	92,019,000	62,863,000	92,019,000	'
Total assets	156,990,000	196,998,000	156,990,000	196,998,000	'
Operating Segments [Member] | Corporate And Eliminations [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	-817,000	-66,000	-2,100,000	-261,000	'
Costs and Expenses [Abstract]	'	'	'	'	'
Operating Expenses	-792,000	-5,000	-2,023,000	-146,000	'
Administrative and general	6,910,000	8,487,000	24,848,000	25,094,000	'
Depreciation and amortization	742,000	854,000	2,287,000	1,775,000	'
Total costs and expenses	6,860,000	9,336,000	25,112,000	26,723,000	'
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	0	141,000	0	'
Operating Income (Loss)	-7,677,000	-9,402,000	-27,071,000	-26,984,000	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Derivative gains (losses), net	-1,084,000	-157,000	-5,245,000	-939,000	'
Foreign currency gains (losses), net	361,000	295,000	-200,000	232,000	'
Other Nonoperating Income (Expense)	-60,000	-47,000	-129,000	14,000	'
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	0	0	0	'
Capital Expenditures	'	'	1,763,000	3,604,000	'
Property, Plant and Equipment, Gross	30,951,000	29,834,000	30,951,000	29,834,000	'
Accumulated depreciation	10,452,000	8,295,000	10,452,000	8,295,000	'
Property, Plant and Equipment, Net In Service	20,499,000	21,539,000	20,499,000	21,539,000	'
Construction in Progress, Gross	41,000	439,000	41,000	439,000	'
Net property and equipment	20,540,000	21,978,000	20,540,000	21,978,000	'
Investments, at Equity, and Advances to 50% or Less Owned Companies	0	0	0	0	'
Inventories	0	0	0	0	'
Goodwill	0	0	0	0	'
Intangible Assets, Net	0	0	0	0	'
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	23,060,000	43,618,000	23,060,000	43,618,000	'
Intersegment Eliminations [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	0	0	0	0	'
Intersegment Eliminations [Member] | Offshore Marine Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	-25,000	26,000	77,000	78,000	'
Intersegment Eliminations [Member] | Inland River Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	-792,000	0	2,023,000	0	'
Intersegment Eliminations [Member] | Shipping Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	0	0	0	108,000	'
Intersegment Eliminations [Member] | Ethanol and Industrial Alcohol [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	0	0	0	0	'
Intersegment Eliminations [Member] | Other Segments [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	0	40,000	0	75,000	'
Intersegment Eliminations [Member] | Corporate And Eliminations [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating Revenues	817,000	-66,000	-2,100,000	-261,000	'
Segment Reconciling Items [Member]	'	'	'	'	'
Other Income and Expenses [Abstract]	'	'	'	'	'
Other Income (Expense) not included in Segment Profit	7,389,000	7,916,000	11,214,000	3,086,000	'
Less Equity Earnings included in Segment Profit	-230,000	1,297,000	-7,071,000	-6,659,000	'
Cash And Near Cash Assets	608,341,000	591,916,000	608,341,000	591,916,000	'
Assets of Disposal Group, Including Discontinued Operation	'	$1,005,147,000	'	$1,005,147,000	'

Discontinued_Operations_Detail

Discontinued Operations (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Operating Revenues	$336,784	$338,855	$919,411	$945,929
Administrative and general	31,463	39,509	101,826	110,801
Depreciation and amortization	33,503	34,347	100,834	97,269
Total costs and expenses	304,506	327,861	883,226	915,039
Gain (Loss) on Sale of Assets and Asset Impairment Charges	19,230	9,064	33,550	16,183
Operating Income (Loss)	51,508	20,058	69,735	47,073
Nonoperating Income (Expense)	-4,985	-1,820	-16,471	3,602
Income Tax Expense (Benefit)	15,984	7,702	21,306	20,412
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	230	-1,297	7,071	6,659
Net Income	30,769	15,504	28,704	63,176
SES Business [Member]	'	'	'	'
Operating Revenues	0	0	0	22,387
Operating Expenses	0	0	0	18,234
Administrative and general	0	0	0	4,587
Depreciation and amortization	0	0	0	1,428
Total costs and expenses	0	0	0	24,249
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	0	0	-71
Operating Income (Loss)	0	0	0	-1,933
Nonoperating Income (Expense)	0	0	-1,537	24,971
Income Tax Expense (Benefit)	0	0	-538	4,305
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	0	0	302
Net Income	0	0	-999	19,035
SEI [Member]	'	'	'	'
Operating Revenues	0	76,296	0	392,614
Operating Expenses	0	71,789	0	382,589
Administrative and general	0	613	0	3,749
Depreciation and amortization	0	1	0	-3
Total costs and expenses	0	72,403	0	386,335
Operating Income (Loss)	0	3,893	0	6,279
Nonoperating Income (Expense)	0	-2,545	-143	-2,540
Income Tax Expense (Benefit)	0	608	-50	1,711
Net Income	0	740	-93	2,028
Era Group [Member]	'	'	'	'
Operating Revenues	0	77,989	22,892	202,026
Operating Expenses	0	46,235	14,076	124,913
Administrative and general	0	10,338	2,653	27,210
Depreciation and amortization	0	10,937	3,875	31,031
Total costs and expenses	0	67,510	20,604	183,154
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	613	548	3,455
Operating Income (Loss)	0	11,092	2,836	22,327
Nonoperating Income (Expense)	0	-2,819	-1,316	-5,955
Income Tax Expense (Benefit)	0	2,967	10,818	5,737
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	219	65	-5,444
Net Income	0	5,525	-9,233	5,191
Consolidation, Eliminations [Member]	'	'	'	'
Operating Revenues	0	-31,082	0	-86,206
Operating Expenses	0	-31,082	0	-86,204
Administrative and general	0	0	0	-2
Total costs and expenses	0	-31,082	0	-86,206
Operating Income (Loss)	$0	$0	$0	$0

Restatement_Details

Restatement (Details) (USD $)	3 Months Ended		9 Months Ended			9 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2013
						Scenario, Previously Reported [Member]	Era Group [Member]	Era Group [Member]	Era Group [Member]	Era Group [Member]	Era Group [Member]
Liability for Uncertain Tax Positions, Current	'	'	'	'	'	'	$10,100,000	'	$10,100,000	'	$10,100,000
Other current liabilities	124,777,000	'	124,777,000	'	93,093,000	114,663,000	'	'	'	'	'
Total current liabilities	224,824,000	'	224,824,000	'	265,641,000	214,710,000	'	'	'	'	'
Total liabilities	1,470,991,000	'	1,470,991,000	'	1,958,119,000	1,460,877,000	'	'	'	'	'
Retained earnings	1,086,874,000	'	1,086,874,000	'	1,473,509,000	1,096,988,000	'	'	'	'	'
Stockholders' equity attributable to parent, total	1,355,491,000	'	1,355,491,000	'	1,713,654,000	1,365,605,000	'	'	'	'	'
Total equity	1,380,733,000	'	1,380,733,000	'	1,742,675,000	1,390,847,000	'	'	'	'	'
Income (Loss) from Discontinued Operations, Net of Tax	0	6,265,000	-10,325,000	26,254,000	'	-211,000	'	'	'	'	'
Net Income	30,769,000	15,504,000	28,704,000	63,176,000	'	38,818,000	0	5,525,000	-9,233,000	5,191,000	'
Net Income attributable to SEACOR Holdings Inc.	30,291,000	16,102,000	28,574,000	63,839,000	'	38,688,000	'	'	'	'	'
Continuing operations	30,291,000	9,837,000	38,799,000	37,585,000	'	38,799,000	'	'	'	'	'
Discontinued operations, net of tax	0	6,265,000	-10,225,000	26,254,000	'	-111,000	'	'	'	'	'
Continuing operations	$1.52	$0.48	$1.96	$1.83	'	$1.96	'	'	'	'	'
Discontinued operations	$0	$0.31	($0.52)	$1.28	'	($0.01)	'	'	'	'	'
Earnings Per Share, Basic	$1.52	$0.79	$1.44	$3.11	'	$1.95	'	'	'	'	'
Continuing operations	$1.36	$0.47	$1.92	$1.80	'	$1.92	'	'	'	'	'
Discontinued operations	$0	$0.31	($0.51)	$1.26	'	$0	'	'	'	'	'
Earnings Per Share, Diluted	$1.36	$0.78	$1.41	$3.06	'	$1.92	'	'	'	'	'
Comprehensive Income	33,635,000	17,960,000	28,916,000	67,916,000	'	39,030,000	'	'	'	'	'
Comprehensive Income attributable to SEACOR Holdings Inc.	$32,725,000	$18,329,000	$28,806,000	$68,193,000	'	$38,920,000	'	'	'	'	'