Seacor (CKH) 10-Q 28 Apr 15 2015 Q1 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 24, 2015
Document And Entity Information [Abstract]
Entity Registrant Name	SEACOR HOLDINGS INC /NEW/
Entity Central Index Key	859598
Current Fiscal Year End Date	-19
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		18,248,556
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current Assets:
Cash and cash equivalents	$448,011	$434,183
Restricted cash	16,896	16,435
Marketable securities	39,002	58,004
Receivables:
Trade, net of allowance for doubtful accounts	186,583	225,242
Other Receivables	39,805	67,745
Inventories	23,156	22,783
Prepaid expenses and other	8,814	9,011
Total current assets	762,267	833,403
Property and Equipment:
Property, Plant and Equipment, Gross	2,083,035	2,086,957
Accumulated depreciation	918,769	902,284
Property, Plant and Equipment, Other, Net in Service	1,164,266	1,184,673
Construction in progress	339,390	318,000
Net property and equipment	1,503,656	1,502,673
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	483,748	484,157
Construction Reserve Funds & Title XI Reserve Funds	288,529	278,022
Goodwill	62,688	62,759
Intangible Assets, Net	31,955	32,727
Other Assets	47,169	51,292
Total assets	3,180,012	3,245,033
Current Liabilities:
Current portion of long-term debt	44,953	48,499
Accounts payable and accrued expenses	72,738	103,760
Other current liabilities	138,460	119,694
Total current liabilities	256,151	271,953
Long-Term Debt	834,686	834,383
Deferred Income Taxes	413,450	432,546
Other Liabilities, Noncurrent	178,293	188,664
Total liabilities	1,682,580	1,727,546
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; 37,660,827 and 37,505,843 shares issued in 2015 and 2014, respectively	377	375
Additional paid-in capital	1,495,261	1,490,698
Retained earnings	1,175,833	1,195,402
Shares held in Treasury of 19,419,459 and 19,365,716 in 2015 and 2014, respectively, at cost	1,287,460	1,283,476
Accumulated Other Comprehensive Loss, Net of Tax	-5,837	-3,505
Stockholders' equity attributable to parent, total	1,378,174	1,399,494
Noncontrolling interests in subsidiaries	119,258	117,993
Total equity	1,497,432	1,517,487
Liabilities and stockholders' equity, total	$3,180,012	$3,245,033

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Trade receivables, allowance for doubtful accounts	$3,037	$3,162
Common Stock, par value	$0.01	$0.01
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	37,660,827	37,505,843
Treasury stock, shares held in treasury	19,419,456	19,365,716
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
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Operating Revenues	$260,644	$310,017
Costs and Expenses [Abstract]
Operating	199,148	218,976
Administrative and general	38,887	38,077
Depreciation and amortization	31,430	33,392
Total costs and expenses	269,465	290,445
Gains (Losses) on Assets Dispositions and Impairments, Net	-4,846	4,678
Operating Income (Loss)	-13,667	24,250
Other Income (Expense):
Interest income	4,579	4,043
Interest expense	10,512	11,403
Marketable security gains (losses), net	-9,121	5,070
Derivative losses, net	-2,996	-237
Foreign currency losses, net	-1,993	-199
Other, net	-44	-3,655
Total Other Nonoperating Income (Expense)	-20,087	-6,381
Income (Loss) Before Income Tax Expense (Benefit) and Equity in Earnings of 50% or Less Owned Companies	-33,754	17,869
Income Tax Expense (Benefit)	-11,954	6,375
Income (Loss) Before Equity in Earnings of 50% or Less Owned Companies	-21,800	11,494
Equity in Earnings of 50% or Less Owned Companies, Net of Tax	3,899	2,221
Net Income (Loss)	-17,901	13,715
Net Income (Loss) Attributable to Noncontrolling Interest	1,668	2,206
Net Income (Loss) attributable to SEACOR Holdings Inc.	($19,569)	$11,509
Earnings Per Share, Basic	($1.10)	$0.57
Earnings Per Share, Diluted	($1.10)	$0.56
Weighted Average Common Shares Outstanding:
Basic	17,777,725	20,109,373
Weighted Average Number of Shares Outstanding, Diluted	17,777,725	20,546,112

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income Statement (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	($17,901)	$13,715
Foreign Currency translation gain (losses)	-3,734	412
Derivative losses on cash flow hedges	-397	-73
Reclassification of derivative losses on cash flow hedges to equity in earnings of 50% or less owned companies	148	113
Other Comprehensive Income (Loss), before Tax	-3,983	452
Income tax (expense) benefit	1,255	-142
Other Comprehensive Income (Loss), Net of Tax	-2,728	310
Comprehensive Income (Loss)	-20,629	14,025
Comprehensive Income attributable to Noncontrolling Interests in subsidiaries	1,272	2,253
Comprehensive Income (Loss) attributable to SEACOR Holdings Inc.	($21,901)	$11,772

Condensed_Consolidated_Stateme2

Condensed Consolidated Statement Of Changes In Equity (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity	$1,497,432	$1,517,487
Employee Stock Purchase Plan	1,261
Exercise of stock options	911
Director stock awards	-57
Restricted stock	-94
Purchases of treasury shares	-5,245
Amortization of share awards	3,691
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	7
Comprehensive income:
Net loss attributable to SEACOR Holdings Inc.	-19,569
Net Income Attributable to Noncontrolling Interest	1,668
Net Income (Loss)	-17,901
Other comprehensive loss	-2,728
Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity	377	375
Employee Stock Purchase Plan	0
Exercise of stock options	1
Director stock awards	0
Restricted stock	1
Purchases of treasury shares	0
Amortization of share awards	0
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	0
Comprehensive income:
Net loss attributable to SEACOR Holdings Inc.	0
Other comprehensive loss	0
Additional Paid-In Capital [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity	1,495,261	1,490,698
Employee Stock Purchase Plan	0
Exercise of stock options	910
Director stock awards	-57
Restricted stock	-95
Purchases of treasury shares	0
Amortization of share awards	-3,691
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	0
Comprehensive income:
Net loss attributable to SEACOR Holdings Inc.	0
Other comprehensive loss	0
Retained Earnings [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity	1,175,833	1,195,402
Employee Stock Purchase Plan	0
Exercise of stock options	0
Director stock awards	0
Restricted stock	0
Purchases of treasury shares	0
Amortization of share awards	0
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	0
Comprehensive income:
Net loss attributable to SEACOR Holdings Inc.	19,569
Other comprehensive loss	0
Shares Held In Treasury [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity	-1,287,460	-1,283,476
Employee Stock Purchase Plan	1,261
Exercise of stock options	0
Director stock awards	0
Restricted stock	0
Purchases of treasury shares	-5,245
Amortization of share awards	0
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	0
Comprehensive income:
Net loss attributable to SEACOR Holdings Inc.	0
Other comprehensive loss	0
Accumulated Other Comprehensive Loss [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity	-5,837	-3,505
Employee Stock Purchase Plan	0
Exercise of stock options	0
Director stock awards	0
Restricted stock	0
Purchases of treasury shares	0
Amortization of share awards	0
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	0
Comprehensive income:
Net loss attributable to SEACOR Holdings Inc.	0
Other comprehensive loss	2,332
Non-Controlling Interests In Subsidiaries [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity	119,258	117,993
Employee Stock Purchase Plan	0
Exercise of stock options	0
Director stock awards	0
Restricted stock	0
Purchases of treasury shares	0
Amortization of share awards	0
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	7
Comprehensive income:
Net Income Attributable to Noncontrolling Interest	-1,668
Other comprehensive loss	$396

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements Of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Cash Flows [Abstract]
Net Cash Provided by Operating Activities	$71,117	$62,231
Cash Flows from Investing Activities
Purchases of property and equipment	47,430	219,129
Proceeds from disposition of property and equipment	7,228	17,619
Investments in and advances to 50% or less owned companies	16,734	17,102
Return of investments and advances from 50% or less owned companies	16,953	6,050
Payments received on third party leases and notes receivable, net	3,965	1,293
Net increase in restricted cash	461	2,315
Net increase in construction reserve funds and title XI reserve funds	10,507	2,600
Net cash used in investing activities	-46,986	-216,184
Cash Flows from Financing Activities
Payments on long-term debt and capital lease obligations	7,396	2,161
Net repayments on inventory financing arrangements	-1,219	-1,254
Proceeds from issuance of long term debt,	4,435	3
Common stock acquired for treasury	5,245	0
Proceeds and tax benefits from share award plans	2,076	4,602
Dividends paid to noncontrolling interests	-7	-121
Net cash provided by (used in) financing activities	-7,356	1,069
Effect of Exchange Rate Changes on Cash and Cash Equivalents	-2,947	239
Net Increase (Decrease) in Cash and Cash Equivalents	13,828	-152,645
Cash and Cash Equivalents, Beginning of Period	434,183	527,435
Cash and Cash Equivalents, End of Period	$448,011	$374,790

Basis_of_Presentation_and_Acco

Basis of Presentation and Accounting Policy	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation and Accounting Policy	BASIS OF PRESENTATION AND ACCOUNTING POLICIES
	The condensed consolidated financial information for the three months ended March 31, 2015 and 2014 has been prepared by the Company and has not been audited by its independent registered public accounting firm. The condensed consolidated financial statements include the accounts of SEACOR Holdings Inc. and its consolidated subsidiaries. In the opinion of management, all adjustments (consisting of normal recurring adjustments) have been made to fairly present the Company’s financial position as of March 31, 2015, its results of operations for the three months ended March 31, 2015 and 2014, its comprehensive income (loss) for the three months ended March 31, 2015 and 2014, its changes in equity for the three months ended March 31, 2015, and its cash flows for the three months ended March 31, 2015 and 2014. 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, 2014.
	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. Capitalized terms used and not specifically defined herein have the same meaning given those terms in the Company's Annual report on Form 10-K for the year ended December 31, 2014.
	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.
	As of March 31, 2015, deferred revenues of $6.8 million, included in other current liabilities, 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, were contingent upon production and energy sale prices. On August 17, 2012, the customer filed a voluntary petition for chapter 11 bankruptcy, which was converted to chapter 7 in June 2014. The Company is vigorously defending its interest in connection with the bankruptcy filing; however, payments received under the Conveyance subsequent to August 17, 2012 and during the 90 days prior to the filing are subject to bankruptcy court approval. The Company will recognize revenues as approved by the bankruptcy court. All costs and expenses related to these charters were recognized as incurred.
	Property and Equipment. 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 time period beyond which it is typically not justifiable for the Company to continue to operate the asset in the same or similar manner. From time to time, the Company may acquire older assets that have already exceeded the Company’s useful life policy, in which case the Company depreciates such assets based on its best estimate of remaining useful life, typically the next survey or certification date.
	As of March 31, 2015, 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 barges	20
	Inland river liquid tank barges	25
	Inland river towboats	25
	Product tankers - U.S.-flag	25
	Short-sea Container/RORO(1) vessels	20
	Harbor and offshore tugs	25
	Ocean liquid tank barges	25
	Terminal and manufacturing facilities	20
	______________________
	-1	Roll on/Roll off ("RORO").
	Impairment of Long-Lived Assets. The Company performs an impairment analysis of long-lived assets used in operations, including intangible assets, when indicators of impairment are present. If the carrying value of the assets is not recoverable, as determined by the estimated undiscounted cash flows, the carrying value of the assets is reduced to fair value. Generally, fair value is determined using valuation techniques, such as expected discounted cash flows or appraisals, as appropriate. During the three months ended March 31, 2015 and 2014, the Company recognized impairment charges of $6.6 million and $3.9 million, respectively, related to long-lived assets held for use.
	Deferred Gains. 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 three months ended March 31 was as follows (in thousands):
		2015			2014
	Balance at beginning of period	$	159,911		$	124,763
	Amortization of deferred gains included in operating expenses as a reduction to rental expense	(5,641		)	(3,314		)
	Amortization of deferred gains included in gains (losses) on asset dispositions and impairments, net	(1,048		)	(976		)
	Balance at end of period	$	153,222		$	120,473
	Accumulated Other Comprehensive Loss. The components of accumulated other comprehensive 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					Loss
		Adjustments			Hedges, net									Adjustments
	31-Dec-14	$	(3,494	)	$	(16	)		$	5	$	(3,505	)	$	(86	)	$	3
	Other comprehensive loss	(3,338		)	(249		)		—		(3,587		)	(396		)	—		$	(3,983	)
	Income tax benefit	1,168			87				—		1,255			—			—		1,255
	Three months ended	$	(5,664	)	$	(178	)		$	5	$	(5,837	)	$	(482	)	$	3	$	(2,728	)
	31-Mar-15
	Earnings (Loss) Per Share. Basic earnings (loss) 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 (loss) 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 (loss) per common share of SEACOR were as follows (in thousands, except share data):
		Three Months Ended March 31,
		Net Income (Loss) attributable to SEACOR			Average O/S Shares			Per Share
	2015
	Basic Weighted Average Common Shares Outstanding	$	(19,569	)	17,777,725			$	(1.10	)
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—			—
	Convertible Notes(2)(3)	—			—
	Diluted Weighted Average Common Shares Outstanding	$	(19,569	)	17,777,725			$	(1.10	)
	2014
	Basic Weighted Average Common Shares Outstanding	$	11,509		20,109,373			$	0.57
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—			436,739
	Convertible Notes(2)(3)	—			—
	Diluted Weighted Average Common Shares Outstanding	$	11,509		20,546,112			$	0.56
	______________________
	-1	For the three months ended March 31, 2015 and 2014, diluted earnings per common share of SEACOR excluded 1,977,402 and 212,859, respectively, of certain share awards as the effect of their inclusion in the computation would be anti-dilutive.
	-2	For the three months ended March 31, 2015 and 2014, diluted earnings per common share of SEACOR excluded 1,825,326 common shares issuable pursuant to the Company's 3.0% Convertible Senior Notes as the effect of their inclusion in the computation would be anti-dilutive.
	-3	For the three months ended March 31, 2015 and 2014, 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.
	New Accounting Pronouncements. On May 28, 2014, the Financial Accounting Standards Board ("FASB") issued a comprehensive new revenue recognition standard that will supersede nearly all existing revenue recognition guidance under generally accepted accounting principles in the United States. The core principal of the new standard is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The new standard is effective for annual and interim periods beginning after December 15, 2017 and early adoption is permitted. The Company has not yet selected the method of adoption and determined what impact, if any, the adoption of the new standard will have on its consolidated financial position, results of operations or cash flows.
	On February 18, 2015, the FASB issued an accounting standard update that amends the guidance for evaluating whether to consolidate certain legal entities. Specifically, the accounting standard update modifies the method for determining whether limited partnerships and similar legal entities are variable interest entities (“VIEs”) or voting interest entities. Further, it eliminates the presumption that a general partner should consolidate a limited partnership and impacts the consolidation analysis of reporting entities that are involved with VIEs, particularly those that have fee arrangements and related party relationships. The accounting standard update is effective for annual and interim periods beginning after December 15, 2015 and early adoption permitted. The Company has not yet determined what impact, if any, the adoption of the accounting standard update will have on its consolidated financial position, results of operations or cash flows.
	On April 7, 2015, the FASB issued final guidance to simplify the presentation of debt issuance costs by requiring debt issuance costs related to a recognized debt liability to be presented in the balance sheet as a direct deduction from the debt liability rather than as an asset. The recognition and measurement guidance for debt issuance costs have not changed. The new standard requires retrospective application and represents a change in accounting principle. The final guidance is effective for annual and interim periods beginning after December 15, 2015 and early adoption is permitted. As of March 31, 2015, the Company had $10.1 million of debt issuance costs included in other assets in the accompanying condensed consolidated balance sheets.

Business_Acquisitions

Business Acquisitions	3 Months Ended
	Mar. 31, 2015
Business Combinations [Abstract]
Business Acquisitions	BUSINESS ACQUISITIONS
	Witt O'Brien's. On July 11, 2014, the Company acquired a controlling interest in Witt O'Brien's, a global leader in preparedness, crisis management, and disaster response and recovery, through the acquisition of its partner's 45.8% equity interest for $35.4 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 $45.0 million of goodwill being recorded. The preliminary fair value analysis is pending completion of a final valuation for the acquired assets and liabilities.

Equipment_Acquisitions_Disposi

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies	3 Months Ended
	Mar. 31, 2015
Equipment Acquisitions, Dispositions And Depreciation And Impairment Policies [Abstract]
Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies	Property and Equipment. 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 time period beyond which it is typically not justifiable for the Company to continue to operate the asset in the same or similar manner. From time to time, the Company may acquire older assets that have already exceeded the Company’s useful life policy, in which case the Company depreciates such assets based on its best estimate of remaining useful life, typically the next survey or certification date.
	As of March 31, 2015, 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 barges	20
	Inland river liquid tank barges	25
	Inland river towboats	25
	Product tankers - U.S.-flag	25
	Short-sea Container/RORO(1) vessels	20
	Harbor and offshore tugs	25
	Ocean liquid tank barges	25
	Terminal and manufacturing facilities	20
	______________________
	-1	Roll on/Roll off ("RORO").
	EQUIPMENT ACQUISITIONS, DISPOSITIONS AND IMPAIRMENTS
	During the three months ended March 31, 2015, capital expenditures were $47.4 million. Equipment deliveries during the period included one fast support vessel, one wind farm utility vessel and one inland river towboat.
	During the three months ended March 31, 2015, the Company sold one 10,000 barrel inland river tank barge, twelve inland river deck barges and other property and equipment for net proceeds of $7.2 million in cash and gains of $0.8 million, all of which were recognized currently. In addition, the Company recognized previously deferred gains of $1.0 million.
	During the three months ended March 31, 2015, the Company recognized impairment charges of $6.6 million related to the suspended construction of two offshore support vessels.

Investments_At_Equity_And_Adva

Investments, At Equity, And Advances To 50% Or Less Owned Companies	3 Months Ended
	Mar. 31, 2015
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
	MexMar. MexMar operates offshore support vessels in Mexico. During the three months ended March 31, 2015, the Company and its partner each contributed additional capital of $7.9 million in cash to MexMar. In addition, during the three months ended March 31, 2015, MexMar repaid $15.0 million of seller financing.
	Falcon Global. On August 1, 2014 the Company and Montco Global, LLC formed Falcon Global LLC ("Falcon Global") to construct and operate two foreign-flag liftboats. The Company has a 50% ownership interest in Falcon Global. During the three months ended March 31, 2015, the Company and its partner each contributed additional capital of $6.7 million in cash to Falcon Global.
	SCFCo. SCFCo was established to operate towboats and dry-cargo barges on the Parana-Paraguay Rivers in South America and a terminal facility at Port Ibicuy, Argentina. During the three months ended March 31, 2015, the Company and its partner each contributed additional capital of $1.0 million in cash to SCFCo. As of March 31, 2015, the Company had outstanding loans and working capital advances to SCFCo Holdings of $30.6 million.
	Bunge-SCF Grain. Bunge-SCF Grain operates a terminal grain elevator in Fairmont City, Illinois. During the three months ended March 31 2015, the Company received $2.0 million of repayments of working capital advances. As of March 31, 2015, the total balance of working capital advances outstanding was $7.0 million.
	SCF Bunge Marine. SCF Bunge Marine provides towing services on the U.S. Inland River Waterways, primarily the Mississippi River, Illinois River and Ohio River. During the three months ended March 31, 2015, the Company received dividends of $2.5 million from SCF Bunge Marine.
	Dorian. Dorian owns and operates foreign-flag VLGC's servicing the international Liquefied Petroleum Trade. As of March 31, 2015, the Company's carrying value of its investment in Dorian was $140.9 million and its fair value was $121.5 million based on the quoted market price.
	SEA-Access. SEA-Access owns and operates a U.S.-flag crude tanker. During the three months ended March 31, 2015, the Company received dividends of $5.1 million from SEA-Access.
	SeaJon II. SeaJon II owns a U.S.-flag offshore tug on time charter to Trailer Bridge. During the three months ended March 31, 2015, the Company and its partner each contributed additional capital of $1.0 million to Sea Jon II.
	Guarantees. The Company has guaranteed the payment of amounts owed under a vessel charter by one of its 50% or less owned companies, a construction contract for one of its 50% or less owned companies and amounts owed under banking facilities by certain of its 50% or less owned companies. As of March 31, 2015, the total amount guaranteed by the Company under these arrangements was $102.7 million. In addition, as of March 31, 2015, the Company had uncalled capital commitments to two of its 50% or less owned companies totaling $2.0 million.

Commitments_And_Contingencies

Commitments And Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	COMMITMENTS AND CONTINGENCIES
	As of March 31, 2015, the Company's unfunded capital commitments were $459.4 million and included: $153.7 million for 16 offshore support vessels; $1.7 million for two 30,000 barrel inland river liquid tank barges; $11.0 million for eight 10,000 barrel inland river liquid tank barges; $2.7 million for three inland river towboats; $216.9 million for three U.S.-flag product tankers; $56.2 million for one U.S.-flag articulated tug-barge; and $17.2 million for other equipment and improvements. These commitments are payable as follows: $199.1 million is payable during the remainder of 2015; $217.3 million is payable during 2016; $37.6 million is payable during 2017; and $5.4 million is payable during 2018. Subsequent to March 31, 2015, the Company committed to purchase additional equipment for $7.5 million. Of these commitments, approximately $6.8 million may be terminated without further liability other than the payment of liquidated damages of $0.7 million.
	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 ORM during the Deepwater Horizon oil spill response and clean-up in the U.S. Gulf of Mexico. The action now is part of the overall multi-district litigation, In re Oil Spill by the Oil Rig "Deepwater Horizon", MDL No. 2179 filed in the U.S. District Court for the Eastern District of Louisiana ("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, results of operations or cash flows.
	On December 15, 2010, NRC, a subsidiary of the Company prior to the SES Business Transaction, and ORM were named as defendants in one of the several consolidated “master complaints” that have been filed in the overall MDL. The “B3” 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. On July 17, 2014, the Court issued a pretrial order that established a protocol for disclosures clarifying the basis for the “B3” claims asserted against the Clean-Up Responder Defendants, including ORM and NRC, in the MDL. Under this protocol, Plaintiffs who satisfy certain criteria and believe they have specific evidence in support of their claims, including that any Clean-Up Responder Defendant(s) failed to act pursuant to the authority and direction of the federal government in conducting Deepwater Horizon oil spill remediation and clean-up operations, must submit a sworn statement or face dismissal. Plaintiffs’ deadline to serve such sworn statements in support of their claims was September 22, 2014, with the exception of several Plaintiffs who were granted an extension until October 10, 2014. On November 14, 2014, the Clean-Up Responder Defendants and the Plaintiffs’ Steering Committee in the MDL submitted a joint report to the Court regarding claimants’ compliance with the pretrial order.  In this joint report, the parties (i) explained how they complied with the notice requirements of Court’s July 17, 2014 pretrial order, (ii) noted that they had received 102 sworn statements in connection with this pretrial order, and (iii) provided the Court with an assessment of the sworn statements received. An additional sworn statement was received after the joint report was submitted. Procedures and next steps in connection with the “B3” claims will now be addressed by the Court. 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, results of operations or cash flows.
	Subsequent to the filing of the referenced master complaint, ten 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. By court order, all of these additional individuals' cases have been stayed until further notice. 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 13, 2011, the Company was named as a defendant in Mason v. Seacor Marine, LLC, No. 2:11-CV-00826 (E.D. La.), an action in which plaintiff, a former employee, alleges sustaining personal injuries 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, the employee moved to sever his case from the MDL on July 16, 2012, which the Court denied on March 5, 2013. The employee filed a motion asking the Court to reconsider, which was denied on May 3, 2013, and the employee filed a Notice of Appeal to the U.S. Court of Appeals for the Fifth Circuit (“Fifth Circuit”) on May 22, 2013. On July 24, 2013, the Company filed a motion to dismiss for lack of appellate jurisdiction, which was granted on August 16, 2013. The same Company employee has also brought a claim in the M/V Seacor Vanguard vessel’s limitation action in the MDL which relates to any actions that may have been taken by vessels owned by the Company to extinguish the fire. On October 20, 2014, the Company moved for summary judgment, seeking dismissal with prejudice of all of the Company employee’s claims in the MDL in light of the Court’s prior rulings. This motion is still pending decision. 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 sought 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. 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, results of operations or cash flows.
	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 (“Cameron”), Halliburton Energy Services, Inc., and M-I L.L.C. (“M-I”) 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 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. Transocean's limitation action, and thus the remainder of the aforementioned cross-claims, remains pending, although the Court has found Cameron and M-I to be not liable in connection with the Deepwater Horizon incident and resultant oil spill and dismissed these parties from the MDL. 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, results of operations or cash flows.
	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 al., 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, results of operations or cash flows.
	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 ("E&P Settlement") on December 21, 2012, and granted final approval to the Medical Benefits Class Action Settlement ("Medical Settlement") on January 11, 2013. Both class action settlements were appealed to the Fifth Circuit. The Fifth Circuit affirmed the MDL Court’s decision concerning the E&P Settlement on January 10, 2014, and also affirmed the MDL Court’s decision concerning the interpretation of the E&P Settlement with respect to business economic loss claims on March 3, 2014. The appeal of the Medical Settlement, on the other hand, was voluntarily dismissed and the Medical Settlement became effective on February 12, 2014. The deadline for bringing a claim to the Medical Benefits Claims Administrator was one year from the effective date of the Settlement. Although neither the Company, ORM, nor NRC are parties to the settlement agreements, the Company, ORM, and NRC are listed as released parties on the releases accompanying both settlement agreements. Consequently, barring any further successful appeal, 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. The Company believes these settlements have reduced the Company's and ORM's potential exposure, if any, from some of the pending actions described above, and continues to evaluate the settlements' impacts on these cases. 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, results of operations or cash flows.
	ORM recently settled three collective action lawsuits that asserted failure to pay overtime with respect to individuals who provided service on the Deepwater Horizon oil spill response under the Fair Labor Standards Act (“FLSA”). These cases: Himmerite et al. v. O'Brien's Response Management Inc. et al. (E.D. La., Case No.: 2:12-cv-01533) (the “Himmerite Action”); Dennis Prejean v. O'Brien's Response Management Inc. (E.D. La., Case No.: 2:12-cv-01045) (the “Prejean Action”); and 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”) were brought in the United States District Court for the Eastern District of Louisiana on behalf of certain individuals who worked on the Deepwater Horizon oil spill response. In the Singleton action, on February 13, 2014, the parties reached a full and final settlement agreement with respect to all of the Plaintiffs' individual claims for an undisclosed immaterial amount. On April 11, 2014, the Court approved the parties’ settlement and dismissed the Singleton Action with prejudice in its entirety, which extinguished the tolling of claims that had been in place for absent putative plaintiffs.
	In the Prejean action, the parties reached a full and final settlement agreement on November 6, 2014 with respect to all of the Plaintiffs’ individual and collective action claims for an undisclosed immaterial amount. The Court approved the settlement and dismissed the Prejean Action with prejudice in its entirety on November 19, 2014.
	In the Himmerite action, the parties reached a full and final settlement agreement on February 19, 2015 with respect to all of the Plaintiffs' claims for an undisclosed immaterial amount. The Court approved the settlement and dismissed the Himmerite Action with prejudice in its entirety on March 25, 2015, which also extinguished the tolling of claims which had been in place for absent putative plaintiffs.
	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, the Company remains contingently liable for certain obligations, including potential liabilities relating to work performed in connection with the Deepwater Horizon oil spill response. Pursuant to the agreement governing the sale, the Company's potential liability to the purchaser may not exceed the consideration received by the Company for the SES Business Transaction. The Company is currently indemnified under contractual agreements with BP for the potential liabilities relating to work performed in connection with the Deepwater Horizon oil spill response.
	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, results of operations or cash flows.

LongTerm_Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2015
Long-term Debt and Capital Lease Obligations [Abstract]
Long-Term Debt	LONG-TERM DEBT
	As of March 31, 2015, the Company had outstanding letters of credit totaling $31.7 million with various expiration dates through 2018.
	During the three months ended March 31, 2015, the Company made scheduled payments on long-term debt of $1.9 million and made net payments of $1.2 million under inventory financing arrangements. In addition, the Company received advances of $4.4 million and made repayments of $5.5 million on a subsidiary's revolving credit facility.
	SEACOR’s Board of Directors has previously authorized the Company to purchase any or all of its 7.375% Senior Notes due 2019, which may be acquired through open market purchases, privately negotiated transactions or otherwise, depending on market conditions. During the three months ended March 31, 2015, the Company did not repurchase any of its 7.375% Senior Notes due 2019. As of March 31, 2015, the aggregate outstanding principal amount of the Company's 7.375% Senior Notes due 2019 was $233.5 million. Subsequent to March 31, 2015, the Company purchased $9.3 million, in principal amount of its 7.375% Senior Notes for $9.5 million.
	SEA-Vista Credit Facility. On April 15, 2015, SEA-Vista, a consolidated non-wholly owned subsidiary (see Note 9), entered into a $300.0 million credit agreement that matures in 2020 (the "Credit Agreement") and is secured by substantially all of SEA-Vista's tangible and intangible assets with no recourse to SEACOR or its other subsidiaries. The Credit Agreement is comprised of three tranches: (i) a $100.0 million revolving credit facility (the "Revolving Loan"); (ii) an $80.0 million term loan (the "Term A-1 Loan"); and (iii) a $120.0 million delayed draw term loan (the "Term A-2 Loan"). The proceeds from the Credit Agreement will fund SEA-Vista's working capital, general corporate purposes, capital commitments and the repayment of outstanding Title XI Bonds. All three loans bear interest at a variable rate determined by reference to the London Interbank Offered Rate ("LIBOR") plus a margin of between 2.00% and 2.75% as determined in accordance with the Credit Agreement or, at the election of SEA-Vista, a Base Rate plus a margin of between 1.25% and 1.75% as determined in accordance with the Credit Agreement. A quarterly commitment fee is payable based on the unused amounts of all three tranches. On April 16, 2015, SEA-Vista drew $25.0 million under the Revolving Loan and $25.0 million under the Term-A-2 Loan.
	Each of the loans under the Credit Agreement will mature on April 15, 2020 (the "Maturity Date"), which may be accelerated in certain circumstances under the Credit Agreement. The principal of the Term A-1 Loan is repayable commencing in June 2015 in quarterly installments of 1.25% of the aggregate principal amount of the Term A-1 Loan through June 30, 2017. Commencing on September 30, 2017, the principal of each of the Term A-1 Loan and the Term A-2 Loan is repayable in quarterly installments of 2.50% of the aggregate principal amount of such loans, with the outstanding principal balance, interest and all other amounts outstanding for all loans, including the Revolving Loan, due and payable on the Maturity Date.
	Commencing with the calendar year ending December 31, 2016, SEA-Vista is required to make annual prepayments on the Term A-1 Loan and the Term A-2 Loan in an amount equal to 50% of annual excess cash flow (as defined), with prepayments continuing on an annual basis until an amount equal to $75.0 million of the aggregate principal amount of the term loans has been repaid. Each such payment is to be made on or before May 15 of the subsequent calendar year (i.e., commencing May 15, 2017). In addition, SEA-Vista has the right to make optional prepayments on each of the loans without penalty in minimum amounts of $1.0 million.
	The Credit Agreement contains various restrictive covenants including: funded debt to adjusted EBITDA; adjusted EBITDA to interest expense plus amortization; aggregate collateral vessel value to the sum of funded debt and unused and unexpired commitments; and minimum liquidity. In addition, the Credit Agreement restricts the payment of dividends and distributions as defined in the Credit Agreement.
	Title XI Bonds. On April 15, 2015, upon the closing of the SEA-Vista Credit Agreement, SEA-Vista instructed the indenture trustee for the Title XI Bonds to issue notices for redemption of the Title XI Bonds, which are expected to be redeemed on or after June 1, 2015. As of March 31, 2015, the total amount of Title XI Bonds outstanding was $70.8 million, including an unamortized discount of $8.5 million. As a consequence of redeeming the bonds prior to their scheduled maturity in 2024, SEA-Vista will also be required to pay a make whole payment (as defined in the Title XI financing agreements). The Company does not expect the make whole payment to exceed $22.0 million; however, the exact amount cannot be determined until the bonds are redeemed. Upon redemption, the Company will record a loss on extinguishment of debt equal to the then unamortized discount and make whole payment. SEA-Vista intends to fund the redemption of the Title XI Bonds with advances from its Credit Agreement, its restricted cash of $16.6 million and its Title XI reserve funds of $9.6 million.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS
	The fair value of an asset or liability is the price that would be received to sell an asset or transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company utilizes a fair value hierarchy that maximizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value and defines three levels of inputs that may be used to measure fair value. Level 1 inputs are quoted prices in active markets for identical assets or liabilities. Level 2 inputs are observable inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly, including quoted prices for similar assets or liabilities in active markets, quoted prices in markets that are not active, inputs other than quoted prices that are observable for the asset or liability, or inputs derived from observable market data. Level 3 inputs are unobservable inputs that are supported by little or no market activity and are significant to the fair value of the assets or liabilities.
	The Company’s financial assets and liabilities as of March 31, 2015 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)	$	39,002		$	—		$	—
	Derivative instruments (included in other receivables)	653			7,113			—
	Construction reserve funds and Title XI reserve funds	288,529			—			—
	LIABILITIES
	Short sale of marketable securities(1) (included in other current liabilities)	5,786			—			—
	Derivative instruments (included in other current liabilities)	6,603			684			—
	______________________
	-1	Marketable security gains (losses), net include unrealized losses of $8.2 million and unrealized gains of $2.8 million for the three months ended March 31, 2015 and 2014, respectively, related to marketable security positions held by the Company as of March 31, 2015.
	The estimated fair values of the Company’s other financial assets and liabilities as of March 31, 2015 were as follows (in thousands):
					Estimated Fair Value
		Carrying			Level 1			Level 2			Level 3
		Amount
	ASSETS
	Cash, cash equivalents and restricted cash	$	464,907		$	464,907		$	—		$	—
	Investments, at cost, in 50% or less owned companies (included in other assets)	10,442			see below
	Notes receivable from third parties (included in other receivables and other assets)	19,358			see below
	LIABILITIES
	Long-term debt, including current portion(1)	879,639			—			955,181			—
	______________________
	-1	The estimated fair value includes the conversion options on the Company's 2.5% and 3.0% Convertible Senior 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 third parties as the overall returns are uncertain due to certain provisions for additional payments contingent upon future events. Considerable judgment was required in developing certain of the estimates of fair value and, accordingly, the estimates presented herein are not necessarily indicative of the amounts that the Company could realize in a current market exchange.
	The Company’s non-financial assets and liabilities that were measured at fair value during the three months ended March 31, 2015 were as follows (in thousands):
			Level 1			Level 2			Level 3
	ASSETS
	Construction in progress(1)		$	—		$	200		$	—
	______________________
	-1	During the three months ended March 31, 2015, the Company recognized impairment charges of $6.6 million related to the suspended construction of two offshore support vessels. The fair value of the construction in progress was determined based on the scrap value of the hulls.

Derivative_Instruments_And_Hed

Derivative Instruments And Hedging Strategies	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments And Hedging Strategies	DERIVATIVE INSTRUMENTS AND HEDGING STRATEGIES
	Derivative instruments are classified as either assets or liabilities based on their individual fair values. Derivative assets and liabilities are included in other receivables and other current liabilities, respectively, in the accompanying condensed consolidated balance sheets. The fair values of the Company’s derivative instruments as of March 31, 2015 were as follows (in thousands):
		Derivative			Derivative
		Asset			Liability
	Options on equities and equity indices	$	—		$	1,868
	Forward currency exchange, option and future contracts	—			224
	Interest rate swap agreements	—			391
	Commodity swap, option and future contracts:
	Exchange traded	653			4,734
	Non-exchange traded	7,113			70
		$	7,766		$	7,287
	Cash Flow Hedges. Certain of the Company's 50% or less owned companies have interest rate swap agreements designated as cash flow hedges. 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. As of March 31, 2015, the interest rate swaps held by the Company's 50% or less owned companies were as follows:
	•	SCFCo, an Inland River Services 50% or less owned company, had two interest rate swap agreements with maturities in 2015 that call for SCFCo to pay a fixed rate of interest ranging from 1.53% to 1.62% on the aggregate amortized notional value of $15.0 million and receive a variable interest rate based on LIBOR on the aggregate amortized notional value.
	•	SeaJon, a Shipping Services 50% or less owned company, had an interest rate swap agreement maturing in 2017 that calls for SeaJon to pay a fixed interest rate of 2.79% on the amortized notional value of $34.5 million and receive a variable interest rate based on LIBOR on the amortized notional value.
	•	Sea-Cat Crewzer, an Offshore Marine Services 50% or less owned company, had an interest rate swap agreement maturing in 2019 that calls for Sea-Cat Crewzer to pay a fixed rate of interest of 1.52% on the amortized notional value of $24.3 million and receive a variable interest rate based on LIBOR on the amortized notional value.
	•	Sea-Cat Crewzer II, an Offshore Marine Services 50% or less owned company, had an interest rate swap agreement maturing in 2019 that calls for Sea-Cat Crewzer II to pay a fixed rate of interest of 1.52% on the amortized notional value of $27.4 million and receive a variable interest rate based on LIBOR on the amortized notional value.
	•	MexMar, an Offshore Marine Services 50% or less owned company, had two interest rate swap agreements with maturities in 2023 that call for MexMar to pay a fixed rate of interest ranging from 1.97% to 2.05% on the aggregate amortized notional value of $42.6 million and receive a variable interest rate based on LIBOR on the aggregate amortized notional value. On April 22, 2015, MexMar entered into two new interest rate swap agreements with maturities in 2023 that call for MexMar to pay a fixed rate of interest ranging from 1.71% to 1.72% on the aggregate notional value of $82.8 million and receive a variable interest rate based on LIBOR on the aggregate amortized notional value.
	Other Derivative Instruments. The Company recognized gains (losses) on derivative instruments not designated as hedging instruments for the three months ended March 31 as follows (in thousands):
		2015			2014
	Options on equities and equity indices	$	(1,374	)	$	13
	Forward currency exchange, option and future contracts	(304		)	11
	Interest rate swap agreements	(9		)	(65		)
	Commodity swap, option and future contracts:
	Exchange traded	(2,184		)	1,841
	Non-exchange traded	875			(2,037		)
		$	(2,996	)	$	(237	)
	The Company 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.
	The Company enters and settles forward currency exchange, option and future contracts with respect to various foreign currencies. As of March 31, 2015, the outstanding forward currency exchange contracts translated into a net purchase of foreign currencies with an aggregate U.S. dollar equivalent of $3.6 million. These contracts enable the Company to buy currencies in the future at fixed exchange rates, which could offset possible consequences of changes in currency exchange rates with respect to the Company’s business conducted outside of the United States. The Company generally does not enter into contracts with forward settlement dates beyond twelve to eighteen months.
	The Company and certain of its 50% or less owned companies have entered into interest rate swap agreements for the general purpose of providing protection against increases in interest rates, which might lead to higher interest costs. As of March 31, 2015, the interest rate swaps held by the Company or its 50% or less owned companies were as follows:
	•	The Company had an interest rate swap agreement maturing in 2018 that calls for the Company to pay a fixed interest rate of 3.00% on the amortized notional value of $8.3 million and receive a variable interest rate based on Euribor on the amortized notional value.
	•	Dynamic Offshore, an Offshore Marine Services 50% or less owned company, had an interest rate swap agreement maturing in 2018 that calls for Dynamic Offshore to pay a fixed interest rate of 1.30% on the amortized notional value of $91.0 million and receive a variable interest rate based on LIBOR on the amortized notional value.
	•	OSV Partners, an Offshore Marine Services 50% or less owned company, had two interest rate swap agreements with maturities in 2020 that call for OSV Partners to pay a fixed rate of interest ranging from 1.89% to 2.27% on the aggregate amortized notional value of $38.3 million and receive a variable interest rate based on LIBOR on the aggregate amortized notional value.
	•	Dorian, a Shipping Services 50% or less owned company, had six interest rate swap agreements with maturities ranging from 2018 to 2020 that call for Dorian to a pay fixed rate of interest ranging from 2.96% to 5.40% on the aggregate amortized notional value of $116.5 million and receive a variable interest rate based on LIBOR on the aggregate amortized notional value.
	The Company enters and settles positions in various exchange and non-exchange traded commodity swap, option and future contracts. ICP enters into exchange traded positions (primarily corn, ethanol or natural gas) to protect its raw material and finished goods inventory balance from market changes. In the Company’s agricultural commodity trading and logistics business, fixed price future purchase and sale contracts for sugar are included in the Company’s non-exchange traded derivative positions. The Company enters into exchange traded positions to protect these purchase and sale contracts as well as its inventory balances from market changes. As of March 31, 2015, the net market exposure to corn and sugar under these contracts was not material.

Stock_Repurchases

Stock Repurchases	3 Months Ended
	Mar. 31, 2015
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 three months ended March 31, 2015, the Company acquired 33,354 shares of Common Stock for treasury for an aggregate purchase price of $2.3 million. As of March 31, 2015, the remaining authority under the repurchase plan was $147.7 million.
	During the three months ended March 31, 2015, the Company also purchased 40,859 shares of Common Stock for treasury for an aggregate purchase price of $3.0 million from its employees to cover their tax withholding obligations upon the lapsing of restrictions on share awards. These shares were purchased in accordance with the terms of the Company's Share Incentive Plans and not pursuant to the repurchase authorizations granted by SEACOR's Board of Directors.

Noncontrolling_Interests_in_Su

Noncontrolling Interests in Subsidiaries (Notes)	3 Months Ended
	Mar. 31, 2015
Noncontrolling Interest [Abstract]
Noncontrolling Interests in Subsidiaries Disclosure [Text Block]
		NONCONTROLLING INTERESTS IN SUBSIDIARIES
	Noncontrolling interests in the Company's consolidated subsidiaries were as follows (in thousands):
		Noncontrolling Interests				March 31, 2015		December 31, 2014
	Offshore Marine Services:
	Windcat Workboats	25%				$	7,703	$	7,527
	Other	1.8	%	–	33.30%	1,321		1,323
	Inland River Services:
	Other	3	%	–	51.80%	1,100		1,088
	Shipping Services:
	Sea-Vista	49%				89,632		89,680
	Illinois Corn Processing	30%				17,631		16,397
	Other	10	%	–	18.90%	1,871		1,978
						$	119,258	$	117,993
	Windcat Workboats. Windcat Workboats owns and operates the Company’s wind farm utility vessels that are primarily used to move personnel and supplies in the major offshore wind markets of Europe. As of March 31, 2015, the net assets of Windcat Workboats were $30.8 million. During the three months ended March 31, 2015, the net income of Windcat Workboats was $2.3 million, of which $0.6 million was attributable to noncontrolling interests. During the three months ended March 31, 2014, the net loss of Windcat Workboats was $0.6 million, of which $0.2 million was attributable to noncontrolling interests.
	SEA-Vista. SEA-Vista owns and operates the Company's fleet of U.S.-flag product tankers used in the U.S. coastwise trade of crude oil, petroleum and specialty chemical products and holds contracts for the construction of three 50,000 DWT (deadweight tonnage) product tankers. As of March 31, 2015, the net assets of SEA-Vista were $182.9 million. During the three months ended March 31, 2015, the net loss of SEA-Vista was $0.1 million, of which the amount attributable to noncontrolling interests was not material.
	Illinois Corn Processing. Illinois Corn Processing LLC (“ICP”) owns and operates an alcohol manufacturing, storage and distribution facility located in Pekin, IL. As of March 31, 2015, the net assets of ICP were $63.2 million. During the three months ended March 31, 2015, the net income of ICP was $4.1 million, of which $1.2 million was attributable to noncontrolling interests. During the three months ended March 31, 2014, the net income of ICP was $10.6 million, of which $2.0 million was attributable to noncontrolling interests.
	For the twelve months ending March 31, 2014, the noncontrolling member of ICP had invoked a plant shutdown election that is available to each LLC member under certain circumstances; however, under its member rights, the Company elected to keep the plant in operation. As a result, the earnings and losses of ICP were disproportionately allocated to its members during the plant shutdown election period. Effective April 1, 2014, the noncontrolling member of ICP withdrew its plant shutdown election.

Multiemployer_Pension_Plans

Multiemployer Pension Plans	3 Months Ended
	Mar. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Multiemployer Pension Plans	MULTI-EMPLOYER PENSION PLANS
	MNRPF. The cumulative funding deficits of the MNRPF are currently being recovered by additional annual contributions from current employers that are subject to adjustment following the results of future tri-annual actuarial valuations. Prior to 2012, the Company was invoiced and expensed $0.4 million for its allocated share of the then cumulative funding deficits. On February 25, 2015, the High Court approved a new deficit contribution scheme whereby any funding deficit of the MNRPF is to be remedied through funding contributions from all participating current and former employers. Based on an actuarial valuation in 2014, the potential cumulative funding deficit of the MNRPF was $481.6 million (£325.0 million). The MNRPF’s trustee estimates the Company’s allocated share of the cumulative funding deficit to be $6.2 million (£4.2 million), including portions deemed uncollectible due to the non-existence or liquidation of certain former employers. The Company will recognize payroll related operating expenses in the periods invoices are received.
	AMOPP. During the three months ended March 31, 2015, the Company received notification from the AMOPP that the Company's withdrawal liability as of September 30, 2014 was $39.9 million based on an actuarial valuation performed as of that date. That liability may change in future years based on various factors, primarily employee census. As of March 31, 2015, 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.

Share_Based_Compensation

Share Based Compensation	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share Based Compensation	SHARE BASED COMPENSATION
	Transactions in connection with the Company’s share based compensation plans during the three months ended March 31, 2015 were as follows:
	Director stock awards granted	750
	Employee Stock Purchase Plan (“ESPP”) shares issued	20,470
	Restricted stock awards granted	134,650
	Restricted stock awards canceled	—
	Shares released from Deferred Compensation Plan	—
	Stock Option Activities:
	Outstanding as of December 31, 2014	1,546,508
	Granted	43,060
	Exercised	(19,584	)
	Outstanding as of March 31, 2015	1,569,984
	Shares available for future grants and ESPP purchases as of March 31, 2015	928,398

Segment_Information

Segment Information	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION
	The Company’s segment presentation and basis of measurement of segment profit or loss are as previously described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014. The following tables summarize the operating results, capital expenditures and assets of the Company's reportable segments.
		Offshore		Inland		Shipping		ICP(1)(2)		Other		Corporate		Total
		Marine		River		Services		$’000		$’000		and		$’000
		Services		Services		$’000						Eliminations
		$’000		$’000								$’000
	For the three months ended
	31-Mar-15
	Operating Revenues:
	External customers	93,421		55,836		51,407		39,598		20,382		—		260,644
	Intersegment	35		771		—		—		70		(876	)	—
		93,456		56,607		51,407		39,598		20,452		(876	)	260,644
	Costs and Expenses:
	Operating	74,355		41,513		37,131		33,118		13,830		(799	)	199,148
	Administrative and general	13,559		3,884		6,289		562		7,136		7,457		38,887
	Depreciation and amortization	15,366		6,889		6,735		980		500		960		31,430
		103,280		52,286		50,155		34,660		21,466		7,618		269,465
	Gains (Losses) on Asset Dispositions and Impairments, Net	(6,649	)	1,803		—		—		—		—		(4,846	)
	Operating Income (Loss)	(16,473	)	6,124		1,252		4,938		(1,014	)	(8,494	)	(13,667	)
	Other Income (Expense):
	Derivative gains (losses), net	(9	)	82		—		(828	)	(776	)	(1,465	)	(2,996	)
	Foreign currency losses, net	(17	)	(1,121	)	(12	)	—		(40	)	(803	)	(1,993	)
	Other, net	(146	)	—		29		—		8		65		(44	)
	Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	2,975		(274	)	1,141		—		57		—		3,899
	Segment Profit (Loss)	(13,670	)	4,811		2,410		4,110		(1,765	)
	Other Income (Expense) not included in Segment Profit (Loss)													(15,054	)
	Less Equity Earnings included in Segment Profit (Loss)													(3,899	)
	Loss Before Taxes and Equity Earnings													(33,754	)
	Capital Expenditures	24,128		3,916		18,180		776		3		427		47,430
	As of March 30, 2015
	Property and Equipment:
	Historical cost	1,062,061		485,881		454,039		47,256		3,521		30,277		2,083,035
	Accumulated depreciation	(504,926	)	(162,581	)	(219,662	)	(16,468	)	(3,236	)	(11,896	)	(918,769	)
		557,135		323,300		234,377		30,788		285		18,381		1,164,266
	Construction in progress	92,873		25,605		218,729		1,494		234		455		339,390
		650,008		348,905		453,106		32,282		519		18,836		1,503,656
	Investments, at Equity, and Advances to 50% or Less Owned Companies	118,253		101,344		221,658		—		42,493		—		483,748
	Inventories	5,360		2,171		977		13,711		937		—		23,156
	Goodwill	13,367		2,502		1,852		—		44,967		—		62,688
	Intangible Assets	1,515		6,692		146		—		23,602		—		31,955
	Other current and long-term assets, excluding cash and near cash assets(3)	98,766		63,768		24,866		11,421		71,436		12,114		282,371
	Segment Assets	887,269		525,382		702,605		57,414		183,954
	Cash and near cash assets(3)													792,438
	Total Assets													3,180,012
	______________________
	-1	Operating revenues includes $37.2 million of tangible product sales and operating expenses includes $30.7 million of costs of goods sold.
	-2	Inventories includes raw materials of $1.6 million and work in process of $1.7 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		ICP(1)(2)		Other		Corporate		Total
		Marine		River		Services		$’000		$’000		and		$’000
		Services		Services		$’000						Eliminations
		$’000		$’000								$’000
	For the three months ended
	31-Mar-14
	Operating Revenues:
	External customers	128,957		57,011		52,401		58,656		12,992		—		310,017
	Intersegment	44		948		—		—		—		(992	)	—
		129,001		57,959		52,401		58,656		12,992		(992	)	310,017
	Costs and Expenses:
	Operating	94,043		39,674		26,997		47,274		11,936		(948	)	218,976
	Administrative and general	15,160		4,337		5,896		511		3,111		9,062		38,077
	Depreciation and amortization	16,304		7,370		7,754		990		85		889		33,392
		125,507		51,381		40,647		48,775		15,132		9,003		290,445
	Gains (Losses) on Asset Dispositions and Impairments, Net	7,738		853		—		—		(409	)	(3,504	)	4,678
Operating Income (Loss)	11,232		7,431		11,754		9,881		(2,549	)	(13,499	)	24,250
Other Income (Expense):
Derivative gains (losses), net	(61	)	—		—		718		(733	)	(161	)	(237	)
Foreign currency gains (losses), net	107		(327	)	(10	)	—		9		22		(199	)
Other, net	—		(38	)	(3,933	)	193		175		(52	)	(3,655	)
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	2,641		(412	)	753		—		(761	)	—		2,221
Segment Profit (Loss)	13,919		6,654		8,564		10,792		(3,859	)
Other Income (Expense) not included in Segment Profit (Loss)													(2,290	)
Less Equity Earnings included in Segment Profit (Loss)													(2,221	)
Income Before Taxes and Equity Earnings													17,869
Capital Expenditures	22,019		22,162		157,712		1,379		100		15,757		219,129
As of March 31, 2014
Property and Equipment:
Historical cost	1,154,201		495,360		499,084		44,166		3,750		27,651		2,224,212
Accumulated depreciation	(483,230	)	(154,706	)	(231,279	)	(12,374	)	(710	)	(12,212	)	(894,511	)
	670,971		340,654		267,805		31,792		3,040		15,439		1,329,701
Construction in progress	106,872		36,346		164,351		2,118		201		15,641		325,529
	777,843		377,000		432,156		33,910		3,241		31,080		1,655,230
Investments, at Equity, and Advances to 50% or Less Owned Companies	102,543		64,778		199,997		—		89,128		—		456,446
Inventories	6,110		2,705		1,298		13,600		1,249		—		24,962
Goodwill	13,367		2,744		1,852		—		—		—		17,963
Intangible Assets	3,217		7,306		717		—		327		—		11,567
Other current and long-term assets, excluding cash and near cash assets(3)	146,796		50,583		19,032		15,049		42,552		21,714		295,726
Segment Assets	1,049,876		505,116		655,052		62,559		136,497
Cash and near cash assets(3)													683,141
Total Assets													3,145,035
______________________
-1	Operating revenues includes $55.6 million of tangible product sales and operating expenses includes $44.1 million of costs of goods sold.
-2	Inventories includes raw materials of $2.2 million and work in process of $1.8 million.
-3	Cash and near cash assets includes cash, cash equivalents, restricted cash, marketable securities, construction reserve funds and Title XI reserve funds.

Basis_of_Presentation_and_Acco1

Basis of Presentation and Accounting Policy (Policy)	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Basis Of Consolidation	The condensed consolidated financial information for the three months ended March 31, 2015 and 2014 has been prepared by the Company and has not been audited by its independent registered public accounting firm. The condensed consolidated financial statements include the accounts of SEACOR Holdings Inc. and its consolidated subsidiaries. In the opinion of management, all adjustments (consisting of normal recurring adjustments) have been made to fairly present the Company’s financial position as of March 31, 2015, its results of operations for the three months ended March 31, 2015 and 2014, its comprehensive income (loss) for the three months ended March 31, 2015 and 2014, its changes in equity for the three months ended March 31, 2015, and its cash flows for the three months ended March 31, 2015 and 2014. 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, 2014.
	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. Capitalized terms used and not specifically defined herein have the same meaning given those terms in the Company's Annual report on Form 10-K for the year ended December 31, 2014.
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.
	As of March 31, 2015, deferred revenues of $6.8 million, included in other current liabilities, 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, were contingent upon production and energy sale prices. On August 17, 2012, the customer filed a voluntary petition for chapter 11 bankruptcy, which was converted to chapter 7 in June 2014. The Company is vigorously defending its interest in connection with the bankruptcy filing; however, payments received under the Conveyance subsequent to August 17, 2012 and during the 90 days prior to the filing are subject to bankruptcy court approval. The Company will recognize revenues as approved by the bankruptcy court. All costs and expenses related to these charters were recognized as incurred.
Property, Plant and Equipment Disclosure [Text Block]	Property and Equipment. 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 time period beyond which it is typically not justifiable for the Company to continue to operate the asset in the same or similar manner. From time to time, the Company may acquire older assets that have already exceeded the Company’s useful life policy, in which case the Company depreciates such assets based on its best estimate of remaining useful life, typically the next survey or certification date.
	As of March 31, 2015, 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 barges	20
	Inland river liquid tank barges	25
	Inland river towboats	25
	Product tankers - U.S.-flag	25
	Short-sea Container/RORO(1) vessels	20
	Harbor and offshore tugs	25
	Ocean liquid tank barges	25
	Terminal and manufacturing facilities	20
	______________________
	-1	Roll on/Roll off ("RORO").
	EQUIPMENT ACQUISITIONS, DISPOSITIONS AND IMPAIRMENTS
	During the three months ended March 31, 2015, capital expenditures were $47.4 million. Equipment deliveries during the period included one fast support vessel, one wind farm utility vessel and one inland river towboat.
	During the three months ended March 31, 2015, the Company sold one 10,000 barrel inland river tank barge, twelve inland river deck barges and other property and equipment for net proceeds of $7.2 million in cash and gains of $0.8 million, all of which were recognized currently. In addition, the Company recognized previously deferred gains of $1.0 million.
	During the three months ended March 31, 2015, the Company recognized impairment charges of $6.6 million related to the suspended construction of two offshore support vessels.
Schedule of Estimated Useful Life of Newly Acquired Equipment [Table Text Block]	As of March 31, 2015, 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 barges	20
	Inland river liquid tank barges	25
	Inland river towboats	25
	Product tankers - U.S.-flag	25
	Short-sea Container/RORO(1) vessels	20
	Harbor and offshore tugs	25
	Ocean liquid tank barges	25
	Terminal and manufacturing facilities	20
	______________________
	-1	Roll on/Roll off ("RORO").
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]	Impairment of Long-Lived Assets. The Company performs an impairment analysis of long-lived assets used in operations, including intangible assets, when indicators of impairment are present. If the carrying value of the assets is not recoverable, as determined by the estimated undiscounted cash flows, the carrying value of the assets is reduced to fair value. Generally, fair value is determined using valuation techniques, such as expected discounted cash flows or appraisals, as appropriate. During the three months ended March 31, 2015 and 2014, the Company recognized impairment charges of $6.6 million and $3.9 million, respectively, related to long-lived assets held for use.
Deferred Gains [Policy Text Block]	Deferred Gains. 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 three months ended March 31 was as follows (in thousands):
		2015			2014
	Balance at beginning of period	$	159,911		$	124,763
	Amortization of deferred gains included in operating expenses as a reduction to rental expense	(5,641		)	(3,314		)
	Amortization of deferred gains included in gains (losses) on asset dispositions and impairments, net	(1,048		)	(976		)
	Balance at end of period	$	153,222		$	120,473
Schedule Of Deferred Gain Activity [Table Text Block]	Deferred gain activity related to these transactions for the three months ended March 31 was as follows (in thousands):
		2015			2014
	Balance at beginning of period	$	159,911		$	124,763
	Amortization of deferred gains included in operating expenses as a reduction to rental expense	(5,641		)	(3,314		)
	Amortization of deferred gains included in gains (losses) on asset dispositions and impairments, net	(1,048		)	(976		)
	Balance at end of period	$	153,222		$	120,473
Comprehensive Income (Loss) Note	Accumulated Other Comprehensive Loss. The components of accumulated other comprehensive 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					Loss
		Adjustments			Hedges, net									Adjustments
	31-Dec-14	$	(3,494	)	$	(16	)		$	5	$	(3,505	)	$	(86	)	$	3
	Other comprehensive loss	(3,338		)	(249		)		—		(3,587		)	(396		)	—		$	(3,983	)
	Income tax benefit	1,168			87				—		1,255			—			—		1,255
	Three months ended	$	(5,664	)	$	(178	)		$	5	$	(5,837	)	$	(482	)	$	3	$	(2,728	)
	31-Mar-15
Earnings Per Common Share of SEACOR	Earnings (Loss) Per Share. Basic earnings (loss) 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 (loss) 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 (loss) per common share of SEACOR were as follows (in thousands, except share data):
		Three Months Ended March 31,
		Net Income (Loss) attributable to SEACOR			Average O/S Shares			Per Share
	2015
	Basic Weighted Average Common Shares Outstanding	$	(19,569	)	17,777,725			$	(1.10	)
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—			—
	Convertible Notes(2)(3)	—			—
	Diluted Weighted Average Common Shares Outstanding	$	(19,569	)	17,777,725			$	(1.10	)
	2014
	Basic Weighted Average Common Shares Outstanding	$	11,509		20,109,373			$	0.57
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—			436,739
	Convertible Notes(2)(3)	—			—
	Diluted Weighted Average Common Shares Outstanding	$	11,509		20,546,112			$	0.56
	______________________
	-1	For the three months ended March 31, 2015 and 2014, diluted earnings per common share of SEACOR excluded 1,977,402 and 212,859, respectively, of certain share awards as the effect of their inclusion in the computation would be anti-dilutive.
	-2	For the three months ended March 31, 2015 and 2014, diluted earnings per common share of SEACOR excluded 1,825,326 common shares issuable pursuant to the Company's 3.0% Convertible Senior Notes as the effect of their inclusion in the computation would be anti-dilutive.
	-3	For the three months ended March 31, 2015 and 2014, 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.
New Accounting Pronouncements	New Accounting Pronouncements. On May 28, 2014, the Financial Accounting Standards Board ("FASB") issued a comprehensive new revenue recognition standard that will supersede nearly all existing revenue recognition guidance under generally accepted accounting principles in the United States. The core principal of the new standard is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The new standard is effective for annual and interim periods beginning after December 15, 2017 and early adoption is permitted. The Company has not yet selected the method of adoption and determined what impact, if any, the adoption of the new standard will have on its consolidated financial position, results of operations or cash flows.
	On February 18, 2015, the FASB issued an accounting standard update that amends the guidance for evaluating whether to consolidate certain legal entities. Specifically, the accounting standard update modifies the method for determining whether limited partnerships and similar legal entities are variable interest entities (“VIEs”) or voting interest entities. Further, it eliminates the presumption that a general partner should consolidate a limited partnership and impacts the consolidation analysis of reporting entities that are involved with VIEs, particularly those that have fee arrangements and related party relationships. The accounting standard update is effective for annual and interim periods beginning after December 15, 2015 and early adoption permitted. The Company has not yet determined what impact, if any, the adoption of the accounting standard update will have on its consolidated financial position, results of operations or cash flows.
	On April 7, 2015, the FASB issued final guidance to simplify the presentation of debt issuance costs by requiring debt issuance costs related to a recognized debt liability to be presented in the balance sheet as a direct deduction from the debt liability rather than as an asset. The recognition and measurement guidance for debt issuance costs have not changed. The new standard requires retrospective application and represents a change in accounting principle. The final guidance is effective for annual and interim periods beginning after December 15, 2015 and early adoption is permitted. As of March 31, 2015, the Company had $10.1 million of debt issuance costs included in other assets in the accompanying condensed consolidated balance sheets.

Basis_of_Presentation_and_Acco2

Basis of Presentation and Accounting Policy Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Schedule of Weighted Average Number of Shares [Table Text Block]	Computations of basic and diluted earnings (loss) per common share of SEACOR were as follows (in thousands, except share data):
		Three Months Ended March 31,
		Net Income (Loss) attributable to SEACOR			Average O/S Shares	Per Share
	2015
	Basic Weighted Average Common Shares Outstanding	$	(19,569	)	17,777,725	$	(1.10	)
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—			—
	Convertible Notes(2)(3)	—			—
	Diluted Weighted Average Common Shares Outstanding	$	(19,569	)	17,777,725	$	(1.10	)
	2014
	Basic Weighted Average Common Shares Outstanding	$	11,509		20,109,373	$	0.57
	Effect of Dilutive Share Awards:
	Options and Restricted Stock(1)	—			436,739
	Convertible Notes(2)(3)	—			—
	Diluted Weighted Average Common Shares Outstanding	$	11,509		20,546,112	$	0.56
	______________________
	-1	For the three months ended March 31, 2015 and 2014, diluted earnings per common share of SEACOR excluded 1,977,402 and 212,859, respectively, of certain share awards as the effect of their inclusion in the computation would be anti-dilutive.
	-2	For the three months ended March 31, 2015 and 2014, diluted earnings per common share of SEACOR excluded 1,825,326 common shares issuable pursuant to the Company's 3.0% Convertible Senior Notes as the effect of their inclusion in the computation would be anti-dilutive.
	-3	For the three months ended March 31, 2015 and 2014, 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.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The Company’s financial assets and liabilities as of March 31, 2015 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)	$	39,002		$	—		$	—
	Derivative instruments (included in other receivables)	653			7,113			—
	Construction reserve funds and Title XI reserve funds	288,529			—			—
	LIABILITIES
	Short sale of marketable securities(1) (included in other current liabilities)	5,786			—			—
	Derivative instruments (included in other current liabilities)	6,603			684			—
	______________________
	-1	Marketable security gains (losses), net include unrealized losses of $8.2 million and unrealized gains of $2.8 million for the three months ended March 31, 2015 and 2014, respectively, related to marketable security positions held by the Company as of March 31, 2015.
Estimated Fair Value Of Other Financial Assets And Liabilities	The estimated fair values of the Company’s other financial assets and liabilities as of March 31, 2015 were as follows (in thousands):
					Estimated Fair Value
		Carrying			Level 1			Level 2			Level 3
		Amount
	ASSETS
	Cash, cash equivalents and restricted cash	$	464,907		$	464,907		$	—		$	—
	Investments, at cost, in 50% or less owned companies (included in other assets)	10,442			see below
	Notes receivable from third parties (included in other receivables and other assets)	19,358			see below
	LIABILITIES
	Long-term debt, including current portion(1)	879,639			—			955,181			—
	______________________
	-1	The estimated fair value includes the conversion options on the Company's 2.5% and 3.0% Convertible Senior 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 three months ended March 31, 2015 were as follows (in thousands):
			Level 1			Level 2			Level 3
	ASSETS
	Construction in progress(1)		$	—		$	200		$	—
	______________________
	-1	During the three months ended March 31, 2015, the Company recognized impairment charges of $6.6 million related to the suspended construction of two offshore support vessels. The fair value of the construction in progress was determined based on the scrap value of the hulls.

Derivative_Instruments_And_Hed1

Derivative Instruments And Hedging Strategies (Tables)	3 Months Ended
	Mar. 31, 2015
Derivative [Line Items]
Fair Values Of Derivative Instruments	The fair values of the Company’s derivative instruments as of March 31, 2015 were as follows (in thousands):
		Derivative			Derivative
		Asset			Liability
	Options on equities and equity indices	$	—		$	1,868
	Forward currency exchange, option and future contracts	—			224
	Interest rate swap agreements	—			391
	Commodity swap, option and future contracts:
	Exchange traded	653			4,734
	Non-exchange traded	7,113			70
		$	7,766		$	7,287
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments	Other Derivative Instruments. The Company recognized gains (losses) on derivative instruments not designated as hedging instruments for the three months ended March 31 as follows (in thousands):
		2015			2014
	Options on equities and equity indices	$	(1,374	)	$	13
	Forward currency exchange, option and future contracts	(304		)	11
	Interest rate swap agreements	(9		)	(65		)
	Commodity swap, option and future contracts:
	Exchange traded	(2,184		)	1,841
	Non-exchange traded	875			(2,037		)
		$	(2,996	)	$	(237	)

Noncontrolling_Interests_in_Su1

Noncontrolling Interests in Subsidiaries (Tables)	3 Months Ended
	Mar. 31, 2015
Noncontrolling Interest [Abstract]
Noncontrolling Interests in Subsidiaries [Table Text Block]	oncontrolling interests in the Company's consolidated subsidiaries were as follows (in thousands):
		Noncontrolling Interests				March 31, 2015		December 31, 2014
	Offshore Marine Services:
	Windcat Workboats	25%				$	7,703	$	7,527
	Other	1.8	%	–	33.30%	1,321		1,323
	Inland River Services:
	Other	3	%	–	51.80%	1,100		1,088
	Shipping Services:
	Sea-Vista	49%				89,632		89,680
	Illinois Corn Processing	30%				17,631		16,397
	Other	10	%	–	18.90%	1,871		1,978
						$	119,258	$	117,993

Share_Based_Compensation_Table

Share Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share Based Compensation Plans	Transactions in connection with the Company’s share based compensation plans during the three months ended March 31, 2015 were as follows:
	Director stock awards granted	750
	Employee Stock Purchase Plan (“ESPP”) shares issued	20,470
	Restricted stock awards granted	134,650
	Restricted stock awards canceled	—
	Shares released from Deferred Compensation Plan	—
	Stock Option Activities:
	Outstanding as of December 31, 2014	1,546,508
	Granted	43,060
	Exercised	(19,584	)
	Outstanding as of March 31, 2015	1,569,984
	Shares available for future grants and ESPP purchases as of March 31, 2015	928,398

Segment_Information_Segment_In

Segment Information Segment Information (Tables)	3 Months Ended
	Mar. 31, 2015
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		ICP(1)(2)		Other		Corporate		Total
		Marine		River		Services		$’000		$’000		and		$’000
		Services		Services		$’000						Eliminations
		$’000		$’000								$’000
	For the three months ended
	31-Mar-15
	Operating Revenues:
	External customers	93,421		55,836		51,407		39,598		20,382		—		260,644
	Intersegment	35		771		—		—		70		(876	)	—
		93,456		56,607		51,407		39,598		20,452		(876	)	260,644
	Costs and Expenses:
	Operating	74,355		41,513		37,131		33,118		13,830		(799	)	199,148
	Administrative and general	13,559		3,884		6,289		562		7,136		7,457		38,887
	Depreciation and amortization	15,366		6,889		6,735		980		500		960		31,430
		103,280		52,286		50,155		34,660		21,466		7,618		269,465
	Gains (Losses) on Asset Dispositions and Impairments, Net	(6,649	)	1,803		—		—		—		—		(4,846	)
	Operating Income (Loss)	(16,473	)	6,124		1,252		4,938		(1,014	)	(8,494	)	(13,667	)
	Other Income (Expense):
	Derivative gains (losses), net	(9	)	82		—		(828	)	(776	)	(1,465	)	(2,996	)
	Foreign currency losses, net	(17	)	(1,121	)	(12	)	—		(40	)	(803	)	(1,993	)
	Other, net	(146	)	—		29		—		8		65		(44	)
	Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	2,975		(274	)	1,141		—		57		—		3,899
	Segment Profit (Loss)	(13,670	)	4,811		2,410		4,110		(1,765	)
	Other Income (Expense) not included in Segment Profit (Loss)													(15,054	)
	Less Equity Earnings included in Segment Profit (Loss)													(3,899	)
	Loss Before Taxes and Equity Earnings													(33,754	)
	Capital Expenditures	24,128		3,916		18,180		776		3		427		47,430
	As of March 30, 2015
	Property and Equipment:
	Historical cost	1,062,061		485,881		454,039		47,256		3,521		30,277		2,083,035
	Accumulated depreciation	(504,926	)	(162,581	)	(219,662	)	(16,468	)	(3,236	)	(11,896	)	(918,769	)
		557,135		323,300		234,377		30,788		285		18,381		1,164,266
	Construction in progress	92,873		25,605		218,729		1,494		234		455		339,390
		650,008		348,905		453,106		32,282		519		18,836		1,503,656
	Investments, at Equity, and Advances to 50% or Less Owned Companies	118,253		101,344		221,658		—		42,493		—		483,748
	Inventories	5,360		2,171		977		13,711		937		—		23,156
	Goodwill	13,367		2,502		1,852		—		44,967		—		62,688
	Intangible Assets	1,515		6,692		146		—		23,602		—		31,955
	Other current and long-term assets, excluding cash and near cash assets(3)	98,766		63,768		24,866		11,421		71,436		12,114		282,371
	Segment Assets	887,269		525,382		702,605		57,414		183,954
	Cash and near cash assets(3)													792,438
	Total Assets													3,180,012
	______________________
	-1	Operating revenues includes $37.2 million of tangible product sales and operating expenses includes $30.7 million of costs of goods sold.
	-2	Inventories includes raw materials of $1.6 million and work in process of $1.7 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		ICP(1)(2)		Other		Corporate		Total
		Marine		River		Services		$’000		$’000		and		$’000
		Services		Services		$’000						Eliminations
		$’000		$’000								$’000
	For the three months ended
	31-Mar-14
	Operating Revenues:
	External customers	128,957		57,011		52,401		58,656		12,992		—		310,017
	Intersegment	44		948		—		—		—		(992	)	—
		129,001		57,959		52,401		58,656		12,992		(992	)	310,017
	Costs and Expenses:
	Operating	94,043		39,674		26,997		47,274		11,936		(948	)	218,976
	Administrative and general	15,160		4,337		5,896		511		3,111		9,062		38,077
	Depreciation and amortization	16,304		7,370		7,754		990		85		889		33,392
		125,507		51,381		40,647		48,775		15,132		9,003		290,445
	Gains (Losses) on Asset Dispositions and Impairments, Net	7,738		853		—		—		(409	)	(3,504	)	4,678
	Operating Income (Loss)	11,232		7,431		11,754		9,881		(2,549	)	(13,499	)	24,250
Other Income (Expense):
Derivative gains (losses), net	(61	)	—		—		718		(733	)	(161	)	(237	)
Foreign currency gains (losses), net	107		(327	)	(10	)	—		9		22		(199	)
Other, net	—		(38	)	(3,933	)	193		175		(52	)	(3,655	)
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	2,641		(412	)	753		—		(761	)	—		2,221
Segment Profit (Loss)	13,919		6,654		8,564		10,792		(3,859	)
Other Income (Expense) not included in Segment Profit (Loss)													(2,290	)
Less Equity Earnings included in Segment Profit (Loss)													(2,221	)
Income Before Taxes and Equity Earnings													17,869
Capital Expenditures	22,019		22,162		157,712		1,379		100		15,757		219,129
As of March 31, 2014
Property and Equipment:
Historical cost	1,154,201		495,360		499,084		44,166		3,750		27,651		2,224,212
Accumulated depreciation	(483,230	)	(154,706	)	(231,279	)	(12,374	)	(710	)	(12,212	)	(894,511	)
	670,971		340,654		267,805		31,792		3,040		15,439		1,329,701
Construction in progress	106,872		36,346		164,351		2,118		201		15,641		325,529
	777,843		377,000		432,156		33,910		3,241		31,080		1,655,230
Investments, at Equity, and Advances to 50% or Less Owned Companies	102,543		64,778		199,997		—		89,128		—		456,446
Inventories	6,110		2,705		1,298		13,600		1,249		—		24,962
Goodwill	13,367		2,744		1,852		—		—		—		17,963
Intangible Assets	3,217		7,306		717		—		327		—		11,567
Other current and long-term assets, excluding cash and near cash assets(3)	146,796		50,583		19,032		15,049		42,552		21,714		295,726
Segment Assets	1,049,876		505,116		655,052		62,559		136,497
Cash and near cash assets(3)													683,141
Total Assets													3,145,035
______________________
-1	Operating revenues includes $55.6 million of tangible product sales and operating expenses includes $44.1 million of costs of goods sold.
-2	Inventories includes raw materials of $2.2 million and work in process of $1.8 million.
-3	Cash and near cash assets includes cash, cash equivalents, restricted cash, marketable securities, construction reserve funds and Title XI reserve funds.

Basis_of_Presentation_and_Acco3

Basis of Presentation and Accounting Policy Revenue Recognition (Details) (USD $)	Mar. 31, 2015
In Millions, unless otherwise specified
Revenue Recognition [Abstract]
Deferred Revenue	$6.80

Basis_of_Presentation_and_Acco4

Basis of Presentation and Accounting Policy Property and Equipment (Details)	3 Months Ended
	Mar. 31, 2015
Wind Farm Utility Vessel [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	10 years
Inland River Dry Cargo Barges [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	20 years
Inland River Liquid Tank Barges [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	25 years
Inland River Towboats [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	25 years
U.S.-flag Product Tankers [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	25 years
R O R O Vessels [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	20 years
Harbor and Offshore Tugs [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	25 years
Ocean Liquid Tank Barge [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	25 years
Terminal And Manufacturing Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	20 years

Basis_of_Presentation_and_Acco5

Basis of Presentation and Accounting Policy Impairments of Long-Lived Assets (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Offshore Support Vessels [Member]
Asset Impairment Charges	$6.60
Aircraft [Member]
Asset Impairment Charges		$3.90

Basis_of_Presentation_and_Acco6

Basis of Presentation and Accounting Policy Deferred Gains (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Deferred Gains	$153,222	$120,473	$159,911	$124,763
Sales Leaseback and Financed Equipment Sales [Member]
Amortization Of Deferred Gains Included in Operating Expenses As A Reduction To Rental Expense	5,641	3,314
Amortization Of Deferred Gains Included In Gains On Asset Dispositions And Impairments, Net	$1,048	$976

Basis_of_Presentation_and_Acco7

Basis of Presentation and Accounting Policy Accumulated Other Comprehensive Income (Details) (USD $)	3 Months Ended		9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax			($5,664)		($3,494)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax			-178		-16
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax			5		5
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Parent				-3,338
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax, Portion Attributable to Parent				-249
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, Portion Attributable to Parent				0
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent			-3,587
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest				-396
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest			0
Other Comprehensive Income (Loss), before Tax	-3,983	452	-3,983
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax, Portion Attributable to Parent				1,168
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax, Portion Attributable to Parent				87
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax, Portion Attributable to Parent				0
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent			1,255
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax, Portion Attributable to Noncontrolling Interest			0
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax, Portion Attributable to Noncontrolling Interest			0
Other Comprehensive Income (Loss), Tax	-1,255	142	-1,255
Accumulated Other Comprehensive Loss, Net of Tax	-5,837		-5,837	-3,505	-3,505
Other Comprehensive Income (Loss), Net of Tax	-2,728	310	-2,728
Non-Controlling Interests In Subsidiaries [Member]
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax			-482		-86
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax			3		3
Other Comprehensive Income (Loss), Net of Tax	$396

Basis_of_Presentation_and_Acco8

Basis of Presentation and Accounting Policy Earning Per Common Share (Details) (USD $)	3 Months Ended				6 Months Ended	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2014	Dec. 31, 2014
Net Income (Loss) attributable to SEACOR Holdings Inc.	($19,569,000)	$11,509,000
Dilutive Securities, Effect on Basic Earnings Per Share, Options and Restrictive Stock Units	0
Dilutive Securities, Effect on Basic Earnings Per Share, Dilutive Convertible Securities	0	0
Net Income (Loss) Available to Common Stockholders, Diluted	($19,569,000)	$11,509,000
Weighted Average Number of Shares Outstanding, Basic	17,777,725	20,109,373
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	0	436,739
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities	0	0
Weighted Average Number of Shares Outstanding, Diluted	17,777,725	20,546,112
Earnings Per Share, Basic	($1.10)	$0.57
Earnings Per Share, Diluted	($1.10)	$0.56
Stock Compensation Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount			1,977,402	212,859
Three Point Zero Percentage Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount					1,825,326
Two Point Five Percentage Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount						4,200,525

Basis_of_Presentation_and_Acco9

Basis of Presentation and Accounting Policy New Accounting Pronouncements (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015
Accounting Policies [Abstract]
Debt Issuance Cost	$10.10

Business_Acquisitions_Narrativ

Business Acquisitions (Narrative) (Details) (Witt O'Brien's LLC [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Jul. 11, 2014
Witt O'Brien's LLC [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired		45.80%
Payments to Acquire Businesses, Gross	$35.40
Goodwill, Gross		$45

Equipment_Acquisitions_Disposi1

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Property, Plant and Equipment [Line Items]
Payments to Acquire Property, Plant, and Equipment	$47,430,000	$219,129,000
Proceeds from disposition of property and equipment	7,200,000
Gain (Loss) on Disposition of Property Plant Equipment	800,000
Offshore Support Vessels Fast Support [Member]
Property, Plant and Equipment [Line Items]
Number Of Equipments Delivered	1
Wind Farm Utility Vessel [Member]
Property, Plant and Equipment [Line Items]
Number Of Equipments Delivered	1
Inland River Towboat [Member]
Property, Plant and Equipment [Line Items]
Number Of Equipments Delivered	1
Inland River Liquid Tank Barges - 10,000 Barrel [Member]
Property, Plant and Equipment [Line Items]
Number Of Equipments Sold	1
Inland River Deck Barges [Member]
Property, Plant and Equipment [Line Items]
Number Of Equipments Sold	12
Offshore Support Vessels [Member]
Property, Plant and Equipment [Line Items]
Asset Impairment Charges	6,600,000
Gains on Asset Dispositions and Impariments, Net [Member]
Property, Plant and Equipment [Line Items]
Amortization Of Deferred Gains Included In Gains On Asset Dispositions And Impairments, Net	$1,000,000

Investments_At_Equity_And_Adva1

Investments, At Equity, And Advances To 50% Or Less Owned Companies (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014
Schedule Of Equity Method Investments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted			$102,700,000
Allocable Share of Uncalled Capital			2,000,000
Mexmar [Member]
Schedule Of Equity Method Investments [Line Items]
Secured Debt, Repayments	15,000,000
Partners' Capital Account, Contributions		7,900,000
Falcon Global [Member]
Schedule Of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions	6,700,000
SCFCo Holdings [Member]
Schedule Of Equity Method Investments [Line Items]
Outstanding Working Capital Advances At End Of Period	30,600,000
Partners' Capital Account, Contributions	1,000,000
Bunge Scf Grain [Member]
Schedule Of Equity Method Investments [Line Items]
Outstanding Working Capital Advances At End Of Period	7,000,000
SCF Bunge Marine [Member]
Schedule Of Equity Method Investments [Line Items]
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital	2,500,000
Dorian LPG [Member]
Schedule Of Equity Method Investments [Line Items]
Investments, at Equity, and Advances to 50% or Less Owned Companies	140,900,000
Equity Method Investment, Quoted Market Value	121,500,000
SeaJon II [Member]
Schedule Of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions	1,000,000
Sea-Access [Member]
Schedule Of Equity Method Investments [Line Items]
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital	$5,100,000

Commitments_And_Contingencies_

Commitments And Contingencies (Narrative) (Details) (USD $)	12 Months Ended				3 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2013	Mar. 31, 2015	Jun. 30, 2015
	claim	claim	claim	claim	claim
Loss Contingencies [Line Items]
Total unfunded capital commitments					459.4
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year					199.1
Recorded Unconditional Purchase Obligation Due in Second Year					217.3
Recorded Unconditional Purchase Obligation Due in Third Year					37.6
Recorded Unconditional Purchase Obligation Due in Fourth Year					5.4
Wunstell Action [Member]
Loss Contingencies [Line Items]
Claims Filed	2
Master Complaints [Member]
Loss Contingencies [Line Items]
Claims Filed	1
Multi-district Litigation [Member]
Loss Contingencies [Line Items]
Claims Filed		10
Darnell Alexander [Member]
Loss Contingencies [Line Items]
Claims Filed		117	410
Abney Litigation [Member]
Loss Contingencies [Line Items]
Claims Filed			668
Abood Litigation [Member]
Loss Contingencies [Line Items]
Claims Filed				174
Prejean [Member]
Loss Contingencies [Line Items]
Loss Contingency, Claims Settled, Number					3
Offshore Support Vessels [Member]
Loss Contingencies [Line Items]
Total unfunded capital commitments					153.7
Unrecorded Unconditional Purchase Obligation, Maximum Quantity					16
Inland River Liquid Tank Barges - 30,000 Barrel [Member]
Loss Contingencies [Line Items]
Total unfunded capital commitments					1.7
Unrecorded Unconditional Purchase Obligation, Maximum Quantity					2
Inland River Liquid Tank Barges - 10,000 Barrel [Member]
Loss Contingencies [Line Items]
Total unfunded capital commitments					11
Unrecorded Unconditional Purchase Obligation, Maximum Quantity					8
Inland River Towboats [Member]
Loss Contingencies [Line Items]
Total unfunded capital commitments					2.7
Unrecorded Unconditional Purchase Obligation, Maximum Quantity					3
U.S.-flag Product Tankers [Member]
Loss Contingencies [Line Items]
Total unfunded capital commitments					216.9
Unrecorded Unconditional Purchase Obligation, Maximum Quantity					3
U.S. Flag Articulated Tug-Barge [Member]
Loss Contingencies [Line Items]
Total unfunded capital commitments					56.2
Unrecorded Unconditional Purchase Obligation, Maximum Quantity					1
Other Machinery and Equipment [Member]
Loss Contingencies [Line Items]
Total unfunded capital commitments					17.2
Subsequent Event [Member]
Loss Contingencies [Line Items]
Total unfunded capital commitments						7.5
Unconditional Purchase Obligation, Amount Eligible for Termination						6.8
Unconditional Purchase Obligations, Liquidated Damages						$0.70

LongTerm_Debt_Details

Long-Term Debt (Details) (USD $)	3 Months Ended		9 Months Ended	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Sep. 30, 2014	Jun. 30, 2015	Dec. 31, 2014	Apr. 15, 2015	Apr. 16, 2015
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount					$31,700,000
Repayments of long-term debt			1,900,000
Net borrowings (repayments) on inventory financing arrangements	-1,219,000	-1,254,000
Proceeds from Lines of Credit			4,400,000
Repayments of Lines of Credit			-5,500,000
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%
Long-term Debt	233,500,000
Title Eleven Bonds [Member]
Debt Instrument [Line Items]
Restricted Cash and Cash Equivalents	16,600,000
Bond Reserve Fund Balance	9,600,000
Long-term Debt	70,800,000
Debt Instrument, Unamortized Discount	8,500,000
Subsequent Event [Member] | Seven Point Three Seven Five Percentage Senior Notes Due Two Thousand Nineteen Member
Debt Instrument [Line Items]
Debt Instrument, Repurchased Face Amount				9,300,000
Debt Instrument, Repurchase Amount				9,500,000
Subsequent Event [Member] | Maximum [Member] | Title Eleven Bonds [Member]
Debt Instrument [Line Items]
Gains (Losses) on Extinguishment of Debt				22,000,000
Sea-Vista [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity						300,000,000
Sea-Vista [Member] | Subsequent Event [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Fair Value of Amount Outstanding							25,000,000
Line of Credit Facility, Maximum Borrowing Capacity				100,000,000
Sea-Vista [Member] | Subsequent Event [Member] | Term A-1 Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal				1.25%
Debt Instrument, Unused Borrowing Capacity, Amount						80,000,000
Sea-Vista [Member] | Subsequent Event [Member] | Term A-2 Loan [Member]
Debt Instrument [Line Items]
Long-term Debt							25,000,000
Debt Instrument, Periodic Payment, Principal				2.50%
Debt Instrument, Unused Borrowing Capacity, Amount						120,000,000
Sea-Vista [Member] | Subsequent Event [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Prepayment Increments				1,000,000
Sea-Vista [Member] | Subsequent Event [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Mandatory Prepayment Balance				$75,000,000
London Interbank Offered Rate (LIBOR) [Member] | Sea-Vista [Member] | Subsequent Event [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate				2.00%
London Interbank Offered Rate (LIBOR) [Member] | Sea-Vista [Member] | Subsequent Event [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate				2.75%
Base Rate [Member] | Sea-Vista [Member] | Subsequent Event [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate				1.25%
Base Rate [Member] | Sea-Vista [Member] | Subsequent Event [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate				1.75%

Fair_Value_Measurements_Financ

Fair Value Measurements (Financial Assets And Liabilities Measured At Fair Value On Recurring Basis) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Construction Reserve Funds & Title XI Reserve Funds	$288,529,000		$278,022,000
Marketable security gains (losses), net	-8,200,000	2,800,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	39,002,000
Derivative instruments (included in other receivables)	653,000
Construction Reserve Funds & Title XI Reserve Funds	288,529,000
Short sales of marketable securities	5,786,000
Derivative instruments (included in other current liabilities)	6,603,000
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0
Derivative instruments (included in other receivables)	7,113,000
Construction Reserve Funds & Title XI Reserve Funds	0
Short sales of marketable securities	0
Derivative instruments (included in other current liabilities)	684,000
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0
Derivative instruments (included in other receivables)	0
Construction Reserve Funds & Title XI Reserve Funds	0
Short sales of marketable securities	0
Derivative instruments (included in other current liabilities)	$0

Fair_Value_Measurements_Estima

Fair Value Measurements (Estimated Fair Value Of Other Financial Assets And Liabilities) (Details) (USD $)	Mar. 31, 2015
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	$464,907
Investments, at cost, in 50% or less owned companies (included in other assets), Carrying Amount	10,442
Notes receivable from other business ventures (included in other receivables and other assets)	19,358
Long-term debt, including current portion, Carrying Amount	879,639
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash, Cash Equivalents and Restricted Cash, Fair Value Disclosure	464,907
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, Cash Equivalents and Restricted Cash, Fair Value Disclosure	0
Debt Instrument, Fair Value Disclosure	955,181
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash, Cash Equivalents and Restricted Cash, 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%
Three Point Zero Percentage Convertible Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.00%

Fair_Value_Measurements_NonFin

Fair Value Measurements (Non-Financial Assets And Liabilities Measured At Fair Value) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Construction in progress	$339,390,000	$318,000,000
Offshore Support Vessels [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges	6,600,000
Offshore Support Vessels [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Construction in progress	0
Offshore Support Vessels [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Construction in progress	200,000
Offshore Support Vessels [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Construction in progress	$0

Derivative_Instruments_And_Hed2

Derivative Instruments And Hedging Strategies (Fair Values Of Derivative Instruments) (Details) (USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	$7,766
Derivative Liability	7,287
Options on equities and equity indices
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	0
Derivative Liability	1,868
Foreign currency exchange, option and future contracts
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	0
Derivative Liability	224
Interest rate swap agreements
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	0
Derivative Liability	391
Commodity swap, option and future contracts, exchange traded
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	653
Derivative Liability	4,734
Commodity swap, option and future contracts, non-exchange traded
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	7,113
Derivative Liability	$70

Derivative_Instruments_And_Hed3

Derivative Instruments And Hedging Strategies (Narrative) (Details) (Cash Flow Hedging [Member], USD $)	Mar. 31, 2015	Jun. 30, 2015
In Millions, unless otherwise specified
SCFCo Holdings [Member]
Derivative [Line Items]
Fixed interest rate range, minimum	1.53%
Fixed interest rate range, maximum	1.62%
Derivative, Notional Amount	$15
Seajon [Member]
Derivative [Line Items]
Fixed interest rate	2.79%
Derivative, Notional Amount	34.5
Sea Cat Crewzer [Member]
Derivative [Line Items]
Fixed interest rate	1.52%
Derivative, Notional Amount	24.3
Sea-Cat Crewzer II [Member]
Derivative [Line Items]
Fixed interest rate	1.52%
Derivative, Notional Amount	27.4
Mexmar [Member]
Derivative [Line Items]
Fixed interest rate range, minimum	1.97%
Fixed interest rate range, maximum	2.05%
Derivative, Notional Amount	42.6
Subsequent Event [Member] | Mexmar [Member]
Derivative [Line Items]
Fixed interest rate range, minimum		1.71%
Fixed interest rate range, maximum		1.72%
Derivative, Notional Amount		$82.80

Derivative_Instruments_And_Hed4

Derivative Instruments And Hedging Strategies (Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Sep. 30, 2014
Derivative [Line Items]
Derivative gains (losses), net	($2,996,000)	($237,000)
Options on equities and equity indices
Derivative [Line Items]
Derivative gains (losses), net	-1,374,000	13,000
Forward Currency Exchange, Option And Future Contracts [Member]
Derivative [Line Items]
Derivative gains (losses), net	-304,000	11,000
Interest rate swap agreements
Derivative [Line Items]
Derivative gains (losses), net	-9,000	-65,000
Commodity swap, option and future contracts, exchange traded
Derivative [Line Items]
Derivative gains (losses), net	-2,184,000	1,841,000
Commodity swap, option and future contracts, non-exchange traded
Derivative [Line Items]
Derivative gains (losses), net	875,000	-2,037,000
Not Designated as Hedging Instrument [Member] | Forward Currency Exchange, Option And Future Contracts [Member]
Derivative [Line Items]
Derivative, Notional Amount	3,600,000
Not Designated as Hedging Instrument [Member] | Interest rate swap agreements
Derivative [Line Items]
Derivative, Fixed Interest Rate	3.00%
Derivative, Notional Amount	8,300,000
Not Designated as Hedging Instrument [Member] | Dynamic Offshore Drilling Ltd [Member] | Interest rate swap agreements
Derivative [Line Items]
Derivative, Fixed Interest Rate	1.30%
Derivative, Notional Amount	91,000,000
Not Designated as Hedging Instrument [Member] | OSV Partners [Member] | Interest rate swap agreements
Derivative [Line Items]
Derivative, Lower Fixed Interest Rate Range	1.89%
Derivative, Higher Fixed Interest Rate Range			2.27%
Derivative, Notional Amount	38,300,000
Not Designated as Hedging Instrument [Member] | Dorian LPG [Member] | Interest rate swap agreements
Derivative [Line Items]
Derivative, Lower Fixed Interest Rate Range	2.96%
Derivative, Higher Fixed Interest Rate Range				5.40%
Derivative, Notional Amount	$116,500,000

Stock_Repurchases_Details

Stock Repurchases (Details) (USD $)	3 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2015	Sep. 30, 2014	Dec. 31, 2013
Common Stock, par value	$0.01	$0.01	$0.01
Treasury Stock, Shares, Acquired	33,354
Treasury Stock, Value, Acquired, Cost Method	$2.30
Stock Repurchase Program, Remaining Authorized Repurchase Amount	147.7
Restricted Stock [Member]
Treasury Stock, Shares, Acquired	40,859
Treasury Stock, Value, Acquired, Cost Method	$3

Noncontrolling_Interests_in_Su2

Noncontrolling Interests in Subsidiaries (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2014
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	$119,258,000			$117,993,000
Net Income (Loss)	-17,901,000	13,715,000
Net Income (Loss) Attributable to Noncontrolling Interest	1,668,000	2,206,000
Windcat Workboats Ltd. [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Assets, Net	30,800,000
Net Income (Loss)	2,300,000		-600,000
Net Income (Loss) Attributable to Noncontrolling Interest	600,000	-200,000
Sea-Vista [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Assets, Net	182,900,000
Net Income (Loss)	-100,000
Illinois Corn Processing LLC [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries				16,397,000
Assets, Net	63,200,000
Net Income (Loss)	4,100,000	10,600,000
Net Income (Loss) Attributable to Noncontrolling Interest	1,200,000	2,000,000
Offshore Marine Services [Member] | Windcat Workboats Ltd. [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	7,703,000			7,527,000
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	25.00%
Offshore Marine Services [Member] | Other Offshore Marine Services Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	1,321,000			1,323,000
Inland River Services [Member] | Other Inland River Services Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	1,100,000			1,088,000
Shipping Services [Member] | Sea-Vista [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	89,632,000			89,680,000
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	49.00%
Illinois Corn Processing LLC [Member] | Illinois Corn Processing LLC [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	17,631,000
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	30.00%
Other Segments [Member] | Other Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	$1,871,000			$1,978,000
Minimum [Member] | Offshore Marine Services [Member] | Other Offshore Marine Services Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	1.80%
Minimum [Member] | Inland River Services [Member] | Other Inland River Services Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	3.00%
Minimum [Member] | Other Segments [Member] | Other Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	10.00%
Maximum [Member] | Offshore Marine Services [Member] | Other Offshore Marine Services Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	33.30%
Maximum [Member] | Inland River Services [Member] | Other Inland River Services Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	51.80%
Maximum [Member] | Other Segments [Member] | Other Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	18.90%
U.S.-flag Product Tankers [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity	3
U.S.-flag Product Tankers [Member] | Shipping Services [Member] | Sea-Vista [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity	3

Multiemployer_Pension_Plans_De

Multiemployer Pension Plans (Details)	Sep. 30, 2014	Dec. 31, 2011	Mar. 31, 2015	Mar. 31, 2015
In Millions, unless otherwise specified	American Maritime Officers Pension Plan [Member]	United Kingdom Merchant Navy Ratings Pension Fund [Member]	United Kingdom Merchant Navy Ratings Pension Fund [Member]	United Kingdom Merchant Navy Ratings Pension Fund [Member]
	USD ($)	USD ($)	USD ($)	GBP (£)
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefit Expense		$0.40
Pension And Other Postretirement Benefit Plans, Total Funding Deficit			481.6	325
Pension and Other Postretirement Benefit Plans, Allocated Share of Funding Deficit			6.2	4.2
Pension and other postretirement benefit plans, withdrawal liability	$39.90

Share_Based_Compensation_Share

Share Based Compensation (Share Based Compensation Plans) (Details)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Director stock awards granted	750
Employee Stock Purchase Plan shares issued	20,470
Restricted stock awards granted	134,650
Restricted stock awards forfeited	0
Shares released from Deferred Compensation Plan	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Stock Options, Outstanding as of December 31, 2014	1,546,508
Stock Option, Granted	43,060
Stock Option, Exercised	19,584
Stock Options, Outstanding as of March 31, 2015	1,569,984
Shares available for future grants and ESPP purchases as of March 31, 2015	928,398

Segment_Information_Operating_

Segment Information (Operating Results, Capital Expenditures And Assets By Reportable Segments) (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Operating Revenues	$260,644,000	$310,017,000
Costs and Expenses [Abstract]
Administrative and general	38,887,000	38,077,000
Depreciation and amortization	31,430,000	33,392,000
Total costs and expenses	269,465,000	290,445,000
Gains (Losses) on Assets Dispositions and Impairments, Net	-4,846,000	4,678,000
Operating Income (Loss)	-13,667,000	24,250,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	-2,996,000	-237,000
Foreign currency gains (losses), net	-1,993,000	-199,000
Other Nonoperating Income (Expense)	-44,000	-3,655,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	3,899,000	2,221,000
Income (Loss) Before Income Tax Expense (Benefit) and Equity in Earnings of 50% or Less Owned Companies	-33,754,000	17,869,000
Capital Expenditures	47,430,000	219,129,000
Property, Plant and Equipment, Gross	2,083,035,000		2,086,957,000
Accumulated depreciation	918,769,000		902,284,000
Construction in progress	339,390,000		318,000,000
Net property and equipment	1,503,656,000		1,502,673,000
Inventories	23,156,000		22,783,000
Goodwill	62,688,000		62,759,000
Intangible Assets, Net	31,955,000		32,727,000
Total assets	3,180,012,000	3,145,035,000	3,245,033,000
Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	93,421,000	128,957,000
Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	55,836,000	57,011,000
Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	51,407,000	52,401,000
Illinois Corn Processing LLC [Member]
Segment Reporting Information [Line Items]
Operating Revenues	39,598,000	58,656,000
Other Income and Expenses [Abstract]
Sales Revenue, Goods, Net			37,200,000	55,600,000
Cost of Goods Sold			30,700,000	44,100,000
Inventory, Raw Materials			1,600,000	2,200,000
Inventory, Work in Process			1,700,000	1,800,000
Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues	20,382,000	12,992,000
Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues	260,644,000	310,017,000
Costs and Expenses [Abstract]
Operating Expenses	199,148,000	218,976,000
Administrative and general	38,887,000	38,077,000
Depreciation and amortization	31,430,000	33,392,000
Total costs and expenses	269,465,000	290,445,000
Gains (Losses) on Assets Dispositions and Impairments, Net	-4,846,000	4,678,000
Operating Income (Loss)	-13,667,000	24,250,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	-2,996,000	-237,000
Foreign currency gains (losses), net	-1,993,000	-199,000
Other Nonoperating Income (Expense)	-44,000	-3,655,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	3,899,000	2,221,000
Capital Expenditures	47,430,000	219,129,000
Property, Plant and Equipment, Gross	2,083,035,000	2,224,212,000
Accumulated depreciation	918,769,000	894,511,000
Property, Plant and Equipment, Net In Service	1,164,266,000	1,329,701,000
Construction in progress	339,390,000	325,529,000
Net property and equipment	1,503,656,000	1,655,230,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	483,748,000	456,446,000
Inventories	23,156,000	24,962,000
Goodwill	62,688,000	17,963,000
Intangible Assets, Net	31,955,000	11,567,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	282,371,000	295,726,000
Operating Segments [Member] | Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	93,456,000	129,001,000
Costs and Expenses [Abstract]
Operating Expenses	74,355,000	94,043,000
Administrative and general	13,559,000	15,160,000
Depreciation and amortization	15,366,000	16,304,000
Total costs and expenses	103,280,000	125,507,000
Gains (Losses) on Assets Dispositions and Impairments, Net	-6,649,000	7,738,000
Operating Income (Loss)	-16,473,000	11,232,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	-9,000	-61,000
Foreign currency gains (losses), net	-17,000	107,000
Other Nonoperating Income (Expense)	-146,000	0
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	2,975,000	2,641,000
Segment Profit (Loss)	-13,670,000	13,919,000
Capital Expenditures	24,128,000	22,019,000
Property, Plant and Equipment, Gross	1,062,061,000	1,154,201,000
Accumulated depreciation	504,926,000	483,230,000
Property, Plant and Equipment, Net In Service	557,135,000	670,971,000
Construction in progress	92,873,000	106,872,000
Net property and equipment	650,008,000	777,843,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	118,253,000	102,543,000
Inventories	5,360,000	6,110,000
Goodwill	13,367,000	13,367,000
Intangible Assets, Net	1,515,000	3,217,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	98,766,000	146,796,000
Total assets	887,269,000	1,049,876,000
Operating Segments [Member] | Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	56,607,000	57,959,000
Costs and Expenses [Abstract]
Operating Expenses	41,513,000	39,674,000
Administrative and general	3,884,000	4,337,000
Depreciation and amortization	6,889,000	7,370,000
Total costs and expenses	52,286,000	51,381,000
Gains (Losses) on Assets Dispositions and Impairments, Net	1,803,000	853,000
Operating Income (Loss)	6,124,000	7,431,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	82,000	0
Foreign currency gains (losses), net	-1,121,000	-327,000
Other Nonoperating Income (Expense)	0	-38,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	-274,000	-412,000
Segment Profit (Loss)	4,811,000	6,654,000
Capital Expenditures	3,916,000	22,162,000
Property, Plant and Equipment, Gross	485,881,000	495,360,000
Accumulated depreciation	162,581,000	154,706,000
Property, Plant and Equipment, Net In Service	323,300,000	340,654,000
Construction in progress	25,605,000	36,346,000
Net property and equipment	348,905,000	377,000,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	101,344,000	64,778,000
Inventories	2,171,000	2,705,000
Goodwill	2,502,000	2,744,000
Intangible Assets, Net	6,692,000	7,306,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	63,768,000	50,583,000
Total assets	525,382,000	505,116,000
Operating Segments [Member] | Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	51,407,000	52,401,000
Costs and Expenses [Abstract]
Operating Expenses	37,131,000	26,997,000
Administrative and general	6,289,000	5,896,000
Depreciation and amortization	6,735,000	7,754,000
Total costs and expenses	50,155,000	40,647,000
Gains (Losses) on Assets Dispositions and Impairments, Net	0	0
Operating Income (Loss)	1,252,000	11,754,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	0	0
Foreign currency gains (losses), net	-12,000	-10,000
Other Nonoperating Income (Expense)	29,000	-3,933,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	1,141,000	753,000
Segment Profit (Loss)	2,410,000	8,564,000
Capital Expenditures	18,180,000	157,712,000
Property, Plant and Equipment, Gross	454,039,000	499,084,000
Accumulated depreciation	219,662,000	231,279,000
Property, Plant and Equipment, Net In Service	234,377,000	267,805,000
Construction in progress	218,729,000	164,351,000
Net property and equipment	453,106,000	432,156,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	221,658,000	199,997,000
Inventories	977,000	1,298,000
Goodwill	1,852,000	1,852,000
Intangible Assets, Net	146,000	717,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	24,866,000	19,032,000
Total assets	702,605,000	655,052,000
Operating Segments [Member] | Illinois Corn Processing LLC [Member]
Segment Reporting Information [Line Items]
Operating Revenues	39,598,000	58,656,000
Costs and Expenses [Abstract]
Operating Expenses	33,118,000	47,274,000
Administrative and general	562,000	511,000
Depreciation and amortization	980,000	990,000
Total costs and expenses	34,660,000	48,775,000
Gains (Losses) on Assets Dispositions and Impairments, Net	0	0
Operating Income (Loss)	4,938,000	9,881,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	-828,000	718,000
Foreign currency gains (losses), net	0	0
Other Nonoperating Income (Expense)	0	193,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	0
Segment Profit (Loss)	4,110,000	10,792,000
Capital Expenditures	776,000	1,379,000
Property, Plant and Equipment, Gross	47,256,000	44,166,000
Accumulated depreciation	16,468,000	12,374,000
Property, Plant and Equipment, Net In Service	30,788,000	31,792,000
Construction in progress	1,494,000	2,118,000
Net property and equipment	32,282,000	33,910,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	0	0
Inventories	13,711,000	13,600,000
Goodwill	0	0
Intangible Assets, Net	0	0
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	11,421,000	15,049,000
Total assets	57,414,000	62,559,000
Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues	20,452,000	12,992,000
Costs and Expenses [Abstract]
Operating Expenses	13,830,000	11,936,000
Administrative and general	7,136,000	3,111,000
Depreciation and amortization	500,000	85,000
Total costs and expenses	21,466,000	15,132,000
Gains (Losses) on Assets Dispositions and Impairments, Net	0	-409,000
Operating Income (Loss)	-1,014,000	-2,549,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	-776,000	-733,000
Foreign currency gains (losses), net	-40,000	9,000
Other Nonoperating Income (Expense)	8,000	175,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	57,000	-761,000
Segment Profit (Loss)	-1,765,000	-3,859,000
Capital Expenditures	3,000	100,000
Property, Plant and Equipment, Gross	3,521,000	3,750,000
Accumulated depreciation	3,236,000	710,000
Property, Plant and Equipment, Net In Service	285,000	3,040,000
Construction in progress	234,000	201,000
Net property and equipment	519,000	3,241,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	42,493,000	89,128,000
Inventories	937,000	1,249,000
Goodwill	44,967,000	0
Intangible Assets, Net	23,602,000	327,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	71,436,000	42,552,000
Total assets	183,954,000	136,497,000
Operating Segments [Member] | Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	-876,000	-992,000
Costs and Expenses [Abstract]
Operating Expenses	-799,000	-948,000
Administrative and general	7,457,000	9,062,000
Depreciation and amortization	960,000	889,000
Total costs and expenses	7,618,000	9,003,000
Gains (Losses) on Assets Dispositions and Impairments, Net	0	-3,504,000
Operating Income (Loss)	-8,494,000	-13,499,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	-1,465,000	-161,000
Foreign currency gains (losses), net	-803,000	22,000
Other Nonoperating Income (Expense)	65,000	-52,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	0
Capital Expenditures	427,000	15,757,000
Property, Plant and Equipment, Gross	30,277,000	27,651,000
Accumulated depreciation	11,896,000	12,212,000
Property, Plant and Equipment, Net In Service	18,381,000	15,439,000
Construction in progress	455,000	15,641,000
Net property and equipment	18,836,000	31,080,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	0	0
Inventories	0	0
Goodwill	0	0
Intangible Assets, Net	0	0
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	12,114,000	21,714,000
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0
Intersegment Eliminations [Member] | Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	-35,000	44,000
Intersegment Eliminations [Member] | Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	-771,000	948,000
Intersegment Eliminations [Member] | Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0
Intersegment Eliminations [Member] | Illinois Corn Processing LLC [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0
Intersegment Eliminations [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues	-70,000	0
Intersegment Eliminations [Member] | Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	876,000	-992,000
Segment Reconciling Items [Member]
Other Income and Expenses [Abstract]
Other Income (Expense) not included in Segment Profit (Loss)	15,054,000	2,290,000
Less Equity Earnings (Loss) included in Segment Profit (Loss)	-3,899,000	-2,221,000
Cash And Near Cash Assets	$792,438,000	$683,141,000