Seacor (CKH) 10-Q 26 Apr 16 2016 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2016	Apr. 22, 2016
Document And Entity Information [Abstract]
Entity Registrant Name	SEACOR HOLDINGS INC /NEW/
Entity Central Index Key	859,598
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		17,306,524
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 496,473	$ 530,009
Marketable securities	110,894	138,200
Receivables:
Trade, net of allowance for doubtful accounts of $2,764 and $2,483 in 2016 and 2015, respectively	130,731	159,076
Other Receivables	31,440	27,217
Inventories	18,431	24,768
Prepaid expenses and other	9,615	8,627
Total current assets	797,584	887,897
Property and Equipment:
Property, Plant and Equipment, Gross	2,015,205	2,123,201
Accumulated depreciation	986,048	994,181
Property, Plant and Equipment, Other, Net in Service	1,029,157	1,129,020
Construction in progress	484,472	454,605
Held for sale equipment	86,332	0
Net property and equipment	1,599,961	1,583,625
Investments, at Equity, and Advances to 50% or Less Owned Companies	334,370	331,103
Construction Reserve Funds	255,350	255,408
Goodwill	52,376	52,340
Intangible Assets, Net	25,750	26,392
Other Assets	46,496	48,654
Total assets	3,111,887	3,185,419
Current Liabilities:
Current portion of long-term debt	35,688	35,531
Accounts payable and accrued expenses	50,660	71,952
Other current liabilities	107,811	92,677
Total current liabilities	194,159	200,160
Long-Term Debt	1,018,331	1,034,859
Exchange Option Liability on Subsidiary Convertible Senior Notes	5,747	5,611
Deferred Income Taxes	374,476	389,988
Deferred Gains and Other Liabilities	153,051	163,862
Total liabilities	1,745,764	1,794,480
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; 37,845,556 and 37,684,829 shares issued in 2016 and 2015, respectively	379	377
Additional paid-in capital	1,508,981	1,505,942
Retained earnings	1,099,434	1,126,620
Shares held in Treasury of 20,550,746 and 20,529,929 in 2016 and 2015, respectively, at cost	1,357,809	1,356,499
Accumulated Other Comprehensive Loss, Net of Tax	(7,764)	(5,620)
Stockholders' equity attributable to parent, total	1,243,221	1,270,820
Noncontrolling interests in subsidiaries	122,902	120,119
Total equity	1,366,123	1,390,939
Liabilities and stockholders' equity, total	$ 3,111,887	$ 3,185,419

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Trade receivables, allowance for doubtful accounts	$ 2,764	$ 2,483
Common Stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	37,845,556	37,684,829
Treasury stock, shares held in treasury	20,550,746	20,529,929
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 Statemen

Condensed Consolidated Statements Of Income - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Operating Revenues	$ 213,928,000	$ 260,644,000
Costs and Expenses [Abstract]
Operating	157,468,000	199,148,000
Administrative and general	35,704,000	38,887,000
Depreciation and amortization	30,989,000	31,430,000
Total costs and expenses	224,161,000	269,465,000
Gains (Losses) on Asset Dispositions and Impairments, Net	217,000	(4,846,000)
Operating Loss	(10,016,000)	(13,667,000)
Other Income (Expense):
Interest income	5,593,000	4,579,000
Interest expense	11,935,000	10,512,000
Debt extinguishment gains, net	3,223,000	0
Marketable security losses, net	(25,096,000)	(9,121,000)
Derivative gains (losses), net	2,620,000	(2,996,000)
Foreign currency gains (losses), net	37,000	(1,993,000)
Other, net	268,000	(44,000)
Total Other Nonoperating Income (Expense)	(25,290,000)	(20,087,000)
Loss Before Income Tax Benefit and Equity in Earnings (Losses) of 50% or Less Owned Companies	(35,306,000)	(33,754,000)
Income Tax Benefit	(14,831,000)	(11,954,000)
Loss Before Equity in Earnings (Losses) of 50% or Less Owned Companies	(20,475,000)	(21,800,000)
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	(49,000)	3,899,000
Net Loss	(20,524,000)	(17,901,000)
Net Income Attributable to Noncontrolling Interests in Subsidiaries	6,662,000	1,668,000
Net Loss attributable to SEACOR Holdings Inc.	$ (27,186,000)	$ (19,569,000)
Basic Loss Per Common Share of SEACOR Holdings Inc.	$ (1.62)	$ (1.10)
Diluted Loss Per Common Share of SEACOR Holdings Inc.	$ (1.62)	$ (1.10)
Weighted Average Common Shares Outstanding:
Basic	16,817,368	17,777,725
Diluted	16,817,368	17,777,725

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Loss Statement - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net Loss	$ (20,524)	$ (17,901)
Foreign currency translation losses	(1,868)	(3,734)
Derivative losses on cash flow hedges	(1,830)	(397)
Reclassification of derivative losses on cash flow hedges to equity in earnings (losses) of 50% or less owned companies	224	148
Other	(5)	0
Other Comprehensive Loss, before Tax	(3,479)	(3,983)
Income tax benefit	1,154	1,255
Other Comprehensive Loss, Net of Tax	(2,325)	(2,728)
Comprehensive Loss	(22,849)	(20,629)
Comprehensive Income attributable to Noncontrolling Interests in Subsidiaries	6,481	1,272
Comprehensive Loss attributable to SEACOR Holdings Inc.	$ (29,330)	$ (21,901)

Condensed Consolidated Stateme6

Condensed Consolidated Statement Of Changes In Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Shares Held In Treasury [Member]	Accumulated Other Comprehensive Loss [Member]	Non-Controlling Interests In Subsidiaries [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity	$ 1,390,939	$ 377	$ 1,505,942	$ 1,126,620	$ (1,356,499)	$ (5,620)	$ 120,119
Employee Stock Purchase Plan	1,133	0	0	0	1,133	0	0
Exercise of stock options	483	0	483	0	0	0	0
Director stock awards	55	0	55	0	0	0	0
Restricted stock	(1,168)	2	(1,170)	0	0	0	0
Purchase of conversion option in convertible debt, net of tax	(898)
Purchases of treasury shares	(2,396)	0	0	0	(2,396)	0	0
Amortization of share awards	4,522	0	4,522	0	0	0	0
Cancellation of restricted stock	0	0	47	0	(47)	0	0
Dividends paid to noncontrolling interests	(3,698)	0	0	0	0	0	(3,698)
Comprehensive income:
Net loss attributable to SEACOR Holdings Inc.	(27,186)	0	0	(27,186)	0	0
Net Income Attributable to Noncontrolling Interests in Subsidiaries	6,662						6,662
Net Loss	(20,524)
Other comprehensive loss	(2,325)	0	0	0	0	(2,144)	(181)
Total equity	$ 1,366,123	$ 379	$ 1,508,981	$ 1,099,434	$ (1,357,809)	$ (7,764)	$ 122,902

Condensed Consolidated Stateme7

Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Cash Flows [Abstract]
Net Cash Provided by Operating Activities	$ 42,446	$ 71,117
Cash Flows from Investing Activities
Purchases of property and equipment	47,436	47,430
Proceeds from disposition of property and equipment	246	7,228
Investments in and advances to 50% or less owned companies	7,953	16,734
Return of investments and advances from 50% or less owned companies	1,136	16,953
Net repayments on revolving credit line to 50% or less owned companies	3,394	0
Issuances of third party leases and notes receivable, net	2,023	3,965
Net increase in restricted cash	0	461
Net (increase) decrease in construction reserve funds	(58)	10,507
Net cash used in investing activities	(48,532)	(46,986)
Cash Flows from Financing Activities
Payments on long-term debt and capital lease obligations	32,647	7,396
Net repayments on inventory financing arrangements	0	(1,219)
Proceeds from issuance of long term debt, net of issue costs	12,373	4,435
Purchase of conversion option in convertible debt	1,382	0
Common stock acquired for treasury	2,396	5,245
Proceeds and tax benefits from share award plans	442	2,076
Distributions to noncontrolling interests	(3,698)	(7)
Net cash used in financing activities	(27,308)	(7,356)
Effect of Exchange Rate Changes on Cash and Cash Equivalents	(142)	(2,947)
Net Increase (Decrease) in Cash and Cash Equivalents	(33,536)	13,828
Cash and Cash Equivalents, Beginning of Period	530,009	434,183
Cash and Cash Equivalents, End of Period	$ 496,473	$ 448,011

Basis of Presentation and Accou

Basis of Presentation and Accounting Policy	3 Months Ended
	Mar. 31, 2016
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, 2016 and 2015 has been prepared by the Company and has not been audited by its independent registered certified 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, 2016 , its results of operations for the three months ended March 31, 2016 and 2015 , its comprehensive loss for the three months ended March 31, 2016 and 2015 , its changes in equity for the three months ended March 31, 2016 , and its cash flows for the three months ended March 31, 2016 and 2015 . 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, 2015 . 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, 2015 . 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, 2016 , deferred revenues of $6.8 million , included in other current liabilities in the accompanying condensed consolidated balance sheets, 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. The Company is vigorously defending its interest in connection with the bankruptcy filing; however, payments received under the Conveyance subsequent to May 19, 2012 are subject to creditors' claims in bankruptcy court. The Company will recognize revenues when reasonably assured of a judgment in its favor. 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, 2016 , 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 maintenance and repair costs and the costs of routine overhauls, drydockings and inspections performed on vessels and equipment are charged to operating expense as incurred. Expenditures that extend the useful life or improve the marketing and commercial characteristics of equipment as well as major renewals and improvements to other properties are capitalized. Certain interest costs incurred during the construction of equipment are capitalized as part of the assets’ carrying values and are amortized over such assets’ estimated useful lives. During the three months ended March 31, 2016 , capitalized interest totaled $5.5 million . 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, 2016 and 2015 , the Company recognized impairment charges of $0.4 million and $6.6 million , respectively, related to long-lived assets held for use. The Company had previously identified indicators of impairment for certain of its offshore support vessel classes operated by Offshore Marine Services as a result of continued weak market conditions from the decline in oil and gas prices. These indicators may include a significant decrease in the market price of a long-lived asset or asset group, a significant adverse change in the extent or manner in which a long-lived asset or asset group is being used or in its physical condition, or a current period operating or cash flow loss combined with a history of operating or cash flow losses or a forecast that demonstrates continuing losses associated with the use of a long-lived asset or asset group. As a consequence, the Company estimated the undiscounted cash flows for those asset groups and determined that the carrying value of the long-lived assets would be recovered through the future operations of those asset groups. The preparation of the undiscounted cash flows required management to make certain estimates and assumptions on expected future rates per day worked and utilization levels of the vessel classes based on anticipated future offshore oil and gas exploration and production activity in the geographical regions where the Company operates. If difficult market conditions persist and an anticipated recovery is delayed beyond the Company's expectation, revisions to management's forecasts may result in the Company recording additional impairment charges related to its long-lived assets in future periods. Impairment of 50% or Less Owned Companies. Investments in 50% or less owned companies are reviewed periodically to assess whether there is an other-than-temporary decline in the fair value of the investment. An annual review is performed to consider, among other things, whether the carrying value of the investment is able to be recovered and whether or not the investee’s ability to sustain an earnings capacity would justify the carrying value of the investment. When the Company determines its investment in the 50% or less owned company is not recoverable or the decline in fair value is other-than-temporary, the investment is written down to fair value. Actual results may vary from the Company's estimates due to the uncertainty regarding the projected financial performance of 50% or less owned companies, the severity and expected duration of declines in value, and the available liquidity in the capital markets to support the continuing operations of the 50% or less owned company. During the three months ended March 31, 2016 and 2015 , the Company did not recognize any impairment charges related to its 50% or less owned companies. Income Taxes. During the three months ended March 31, 2016 , the Company's effective tax rate of 42.0% was primarily due to taxes not provided on income attributable to noncontrolling interests (see Note 8). 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 month ended March 31 was as follows (in thousands): 2016 2015 Balance at beginning of period $ 135,909 $ 159,911 Amortization of deferred gains included in operating expenses as a reduction to rental expense (5,658 ) (5,641 ) Amortization of deferred gains included in gains (losses) on asset dispositions and impairments, net (623 ) (1,048 ) Deferred gains on held for sale equipment (1,707 ) — Balance at end of period $ 127,921 $ 153,222 Accumulated Other Comprehensive Loss. The components of accumulated other comprehensive loss were as follows (in thousands): SEACOR Holdings Inc. Stockholders' Equity Noncontrolling Interests Foreign Currency Translation Adjustments Derivative Losses on Cash Flow Hedges, net Other Total Foreign Currency Translation Adjustments Other Other Comprehensive Loss December 31, 2015 $ (5,528 ) $ (116 ) $ 24 $ (5,620 ) $ (528 ) $ 16 Other comprehensive loss (1,689 ) (1,606 ) (3 ) (3,298 ) (179 ) (2 ) $ (3,479 ) Income tax benefit 591 562 1 1,154 — — 1,154 Three Months Ended March 31, 2016 $ (6,626 ) $ (1,160 ) $ 22 $ (7,764 ) $ (707 ) $ 14 $ (2,325 ) Loss Per Share. Basic loss per common share of SEACOR is computed based on the weighted average number of common shares issued and outstanding during the relevant periods. Diluted loss per common share of SEACOR is 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 loss per common share of SEACOR were as follows (in thousands, except share data): Three Months Ended March 31, Net Loss attributable to SEACOR Average O/S Shares Per Share 2016 Basic Weighted Average Common Shares Outstanding $ (27,186 ) 16,817,368 $ (1.62 ) Effect of Dilutive Share Awards: Options and Restricted Stock (1) — — Convertible Notes (2) — — Diluted Weighted Average Common Shares Outstanding $ (27,186 ) 16,817,368 $ (1.62 ) 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 (3) — — Diluted Weighted Average Common Shares Outstanding $ (19,569 ) 17,777,725 $ (1.10 ) ______________________ (1) For the three months ended March 31, 2016 , and 2015 , diluted earnings per common share of SEACOR excluded 1,997,822 and 1,977,402 , 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, 2016 , diluted earnings per common share of SEACOR excluded 3,379,393 common shares issuable pursuant to the Company's 2.5% Convertible Senior Notes, 1,825,326 common shares issuable pursuant to the Company's 3.0% Convertible Senior Notes and 2,243,500 common shares issuable pursuant to the Company's 3.75% Subsidiary 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 , diluted earnings per common share of SEACOR excluded 4,200,525 common shares issuable pursuant to the Company's 2.5% Convertible Senior Notes and 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. 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 or 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 25, 2016, the FASB issued a comprehensive new leasing standard, which improves transparency and comparability among companies by requiring lessees to recognize a lease liability and a corresponding lease asset for virtually all lease contracts. It also requires additional disclosures about leasing arrangements. The new standard is effective for interim and annual periods beginning after December 15, 2018 and requires a modified retrospective approach to adoption. Early adoption is permitted. The Company has not yet determined what impact, if any, the adoption of the new standard will have on its consolidated financial position, results of operations or cash flows.

Investments, At Equity, And Adv

Investments, At Equity, And Advances To 50% Or Less Owned Companies	3 Months Ended
	Mar. 31, 2016
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 Falcon Global. Falcon Global was formed to construct and operate foreign-flag liftboats. During the three months ended March 31, 2016 , the Company and its partner each contributed additional capital of $4.3 million in cash to Falcon Global. SCFCo. SCFCo was established to operate inland river towboats and inland river 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, 2016 , the Company and its partner each contributed additional capital of $0.3 million in cash to SCFCo. As of March 31, 2016 , the Company had outstanding loans and working capital advances to SCFCo of $26.1 million . SEA-Access. SEA-Access owns and operates a U.S.-flag crude oil tanker. During the three months ended March 31, 2016 , the Company received dividends of $1.5 million and capital distributions of $1.1 million from SEA-Access. SeaJon. SeaJon owns an articulated tug-barge operating in the Great Lakes trade. During the three months ended March 31, 2016 , the Company received dividends of $0.6 million from SeaJon. Avion. Avion is a distributor of aircraft and aircraft related parts. During the three months ended March 31, 2016 , the Company made advances of $3.0 million to Avion. As of March 31, 2016 , the Company had $3.0 million of outstanding loans to Avion. VA&E. VA&E primarily focuses on the global origination, trading and merchandising of sugar, pairing producers and buyers and arranging for the transportation and logistics of the product. The Company provides an unsecured revolving credit facility to VA&E for up to $6.0 million . During the three months ended March 31, 2016 , VA&E borrowed $2.1 million and repaid $5.5 million on the revolving credit facility. As of March 31, 2016 , the Company had outstanding advances of $3.6 million to VA&E. Other. During the three months ended March 31, 2016 , the Company made advances of $0.4 million to other 50% or less owned companies. Guarantees. The Company has guaranteed the payment of amounts owed under a vessel charter, a construction contract and banking facilities by certain of its 50% or less owned companies. As of March 31, 2016 , the total amount guaranteed by the Company under these arrangements was $55.2 million . In addition, as of March 31, 2016 , the Company had uncalled capital commitments to two of its 50% or less owned companies totaling $1.9 million .

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2016
Long-term Debt and Capital Lease Obligations [Abstract]
Long-Term Debt	LONG-TERM DEBT SEACOR’s Board of Directors previously approved a securities repurchase plan that authorizes the Company to acquire its 7.375% Senior Notes, 3.0% Convertible Senior Notes, 2.5% Convertible Senior Notes and SEACOR common stock, par value $0.01 per share (“Common Stock”), (collectively the "Securities"), which may be acquired through open market purchases, privately negotiated transactions or otherwise, depending on market conditions. As of March 31, 2016 , the Company's repurchase authority for the Securities was $165.9 million . 2.5% Convertible Senior Notes. During the three months ended March 31, 2016 , the Company repurchased $20.2 million in principal amount of its 2.5% Convertible Senior Notes for total consideration of $18.9 million . Consideration of $17.5 million was allocated to the settlement of the long-term debt resulting in gains on debt extinguishment of $1.4 million included in the accompanying consolidated statements of loss. Consideration of $1.4 million was allocated to the purchase of the conversion option embedded in the 2.5% Convertible Senior Notes as included in the accompanying consolidated statements of changes in equity. 7.375% Senior Notes. During the three months ended March 31, 2016 , the Company purchased $13.9 million in principal amount of its 7.375% Senior Notes for $11.9 million resulting in gains on debt extinguishment of $1.8 million included in the accompanying consolidated statements of loss. SEA-Vista Credit Facility. During the three months ended March 31, 2016 , SEA-Vista borrowed $5.0 million on the Revolving Loan and made scheduled repayments of $1.0 million on the Term A-1 Loan. As of March 31, 2016 , SEA-Vista had $82.0 million of borrowing capacity under the SEA-Vista Credit Facility. Subsequent to March 31, 2016 , SEA-Vista borrowed $32.0 million on the Revolving Loan. ICP Revolving Credit Facility. As of March 31, 2016 , ICP had no borrowings on the ICP Revolving Credit Facility and had $15.5 million of borrowing capacity. Other. During the three months ended March 31, 2016 , the Company made scheduled payments on other long-term debt of $2.2 million and received proceeds from the issuance of other long-term debt of $7.4 million , net of issuance costs of $0.1 million . As of March 31, 2016 , the Company had outstanding letters of credit totaling $25.0 million with various expiration dates through 2019 and had other labor and performance guarantees of $2.7 million .

Derivative Instruments And Hedg

Derivative Instruments And Hedging Strategies	3 Months Ended
	Mar. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments And Hedging Strategies	DERIVATIVE INSTRUMENTS AND HEDGING STRATEGIES Exchange Option Liability on Subsidiary Convertible Senior Notes. The exchange option liability is carried at fair value and relates to a bifurcated embedded derivative in the Company's 3.75% Subsidiary Convertible Senior Notes. The activity of the exchange option liability for the three months ended March 31, 2016 was as follows: Balance as of December 31, 2015 $ 5,611 Unrealized losses included in derivative gains (losses), net 136 Balance as of March 31, 2016 $ 5,747 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. The Company recognized losses on derivative instruments designated as cash flow hedges of $1.8 million and $0.4 million for the three months ended March 31, 2016 and 2015 , respectively, as a component of other comprehensive income (loss). As of March 31, 2016 , the interest rate swaps held by the Company's 50% or less owned companies were as follows: • MexMar had four interest rate swap agreements with maturities in 2023 that call for MexMar to pay a fixed rate of interest ranging from 1.71% to 2.05% on the aggregate amortized notional value of $114.7 million and receive a variable interest rate based on LIBOR on the aggregate amortized notional value. • Sea-Cat Crewzer II 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 $25.0 million and receive a variable interest rate based on LIBOR on the amortized notional value. • Sea-Cat Crewzer 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 $22.2 million and receive a variable interest rate based on LIBOR on the amortized notional value. • SeaJon 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 $32.1 million and receive a variable interest rate based on LIBOR on the amortized notional value. Other Derivative Instruments. Other derivative instruments not designated as hedging 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, 2016 were as follows (in thousands): Derivative Asset Derivative Liability Options on equities and equity indices $ — $ 250 Forward currency exchange, option and future contracts 228 — Interest rate swap agreements — 212 Commodity swap, option and future contracts: Exchange traded 199 1,413 $ 427 $ 1,875 The Company recognized gains (losses) on derivative instruments not designated as hedging instruments for the three month ended March 31 as follows (in thousands): 2016 2015 Options on equities and equity indices $ 2,904 $ (1,374 ) Forward currency exchange, option and future contracts 45 (304 ) Interest rate swap agreements (6 ) (9 ) Commodity swap, option and future contracts: Exchange traded (187 ) (2,184 ) Non-exchange traded — 875 $ 2,756 $ (2,996 ) The Company holds positions in publicly traded equity options that convey the right or obligation to engage in future transactions in 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, 2016 , the outstanding forward currency exchange contracts translated into a net purchase of foreign currencies with an aggregate U.S. dollar equivalent of $2.0 million . These contracts enable the Company to buy currencies in the future at fixed exchange rates, which could offset possible consequences of changes in currency exchange rates with respect to the Company’s business conducted outside of the United States. The Company generally does not enter into contracts with forward settlement dates beyond twelve to eighteen months. The Company 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, 2016 , 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 $5.8 million and receive a variable interest rate based on Euribor on the amortized notional value. • OSV Partners 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 $41.8 million and receive a variable interest rate based on LIBOR on the aggregate amortized notional value. • Dynamic Offshore 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 $81.2 million and receive a variable interest rate based on LIBOR on the amortized notional value. • Falcon Global had an interest rate swap agreement maturing in 2022 that calls for Falcon Global to pay a fixed interest rate of 2.06% on the amortized notional value of $62.5 million and receive a variable interest rate based on LIBOR on the amortized notional value. The Company and certain of its 50% or less owned companies 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 and natural gas) to protect its raw material and finished goods inventory balances from market changes. VA&E enters into exchange traded positions to protect its fixed price future purchase and sale contracts for sugar as well as its inventory balances from market changes. As of March 31, 2016 , the net market exposure to these commodities under these contracts was not material.
Fair Values Of Derivative Instruments	The fair values of the Company’s derivative instruments as of March 31, 2016 were as follows (in thousands): Derivative Asset Derivative Liability Options on equities and equity indices $ — $ 250 Forward currency exchange, option and future contracts 228 — Interest rate swap agreements — 212 Commodity swap, option and future contracts: Exchange traded 199 1,413 $ 427 $ 1,875

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2016
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, 2016 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) $ 110,894 $ — $ — Derivative instruments (included in other receivables) 199 228 — Construction reserve funds 255,350 — — LIABILITIES Short sale of marketable securities (1) (included in other current liabilities) 5,053 — — Derivative instruments (included in other current liabilities) 1,663 212 — Exchange option liability on subsidiary convertible senior notes — — 5,747 ______________________ (1) Marketable security losses, net include unrealized losses of $24.5 million and $0.2 million for the three months ended March 31, 2016 and 2015 , respectively, related to marketable security positions held by the Company as of March 31, 2016 . Level 3 Inputs. The fair value of the exchange option liability on subsidiary convertible senior notes is estimated with significant inputs that are both observable and unobservable in the market and therefore is considered a Level 3 fair value measurement. Observable inputs include market quotes, current interest rates, benchmark yield curves, volatility, quoted prices of securities with similar characteristics and historical dividends. The significant unobservable input used in the fair value measurement is the probability assessment of a SMH Spin-off. In the fair value measurement, holding the observable inputs constant, a significant increase in the probability of a SMH Spin-off would result in a significantly lower exchange option liability. The estimated fair values of the Company’s other financial assets and liabilities as of March 31, 2016 were as follows (in thousands): Estimated Fair Value Carrying Amount Level 1 Level 2 Level 3 ASSETS Cash and cash equivalents $ 496,473 $ 496,473 $ — $ — Investments, at cost, in 50% or less owned companies (included in other assets) 16,045 see below Notes receivable from third parties (included in other receivables and other assets) 22,574 see below LIABILITIES Long-term debt, including current portion (1) 1,054,019 — 1,019,076 — ______________________ (1) The estimated fair value includes the embedded conversion options on the Company's 2.5% and 3.0% Convertible Senior Notes. The carrying value of cash and cash equivalents 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.
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The Company’s financial assets and liabilities as of March 31, 2016 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) $ 110,894 $ — $ — Derivative instruments (included in other receivables) 199 228 — Construction reserve funds 255,350 — — LIABILITIES Short sale of marketable securities (1) (included in other current liabilities) 5,053 — — Derivative instruments (included in other current liabilities) 1,663 212 — Exchange option liability on subsidiary convertible senior notes — — 5,747 ______________________ (1) Marketable security losses, net include unrealized losses of $24.5 million and $0.2 million for the three months ended March 31, 2016 and 2015 , respectively, related to marketable security positions held by the Company as of March 31, 2016 .
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, 2016 were as follows (in thousands): Estimated Fair Value Carrying Amount Level 1 Level 2 Level 3 ASSETS Cash and cash equivalents $ 496,473 $ 496,473 $ — $ — Investments, at cost, in 50% or less owned companies (included in other assets) 16,045 see below Notes receivable from third parties (included in other receivables and other assets) 22,574 see below LIABILITIES Long-term debt, including current portion (1) 1,054,019 — 1,019,076 — ______________________ (1) The estimated fair value includes the embedded conversion options on the Company's 2.5% and 3.0% Convertible Senior Notes.

Stock Repurchases

Stock Repurchases	3 Months Ended
	Mar. 31, 2016
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Stock Repurchases	STOCK REPURCHASES SEACOR’s Board of Directors previously approved a securities repurchase plan that authorizes the Company to acquire its 7.375% Senior Notes, 3.0% Convertible Senior Notes, 2.5% Convertible Senior Notes and Common Stock, (collectively the "Securities"), which may be acquired through open market purchases, privately negotiated transactions or otherwise, depending on market conditions. As of March 31, 2016 , the Company's repurchase authority for the Securities was $165.9 million . During the three months ended March 31, 2016 , the Company purchased 47,455 shares of Common Stock for treasury for an aggregate purchase price of $2.4 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 Sub

Noncontrolling Interests in Subsidiaries (Notes)	3 Months Ended
	Mar. 31, 2016
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, 2016 December 31, 2015 Offshore Marine Services: Windcat Workboats 25% $ 6,682 $ 7,484 Other 1.8 % – 30% 267 470 Inland River Services: Other 3.0 % – 51.8% 960 1,146 Shipping Services: Sea-Vista 49% 95,118 88,290 Illinois Corn Processing 30% 19,392 22,272 Other 5.0 % – 14.6% 483 457 $ 122,902 $ 120,119 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, 2016 , the net assets of Windcat Workboats were $26.7 million . During the three months ended March 31, 2016 , the net loss of Windcat Workboats was $2.5 million , of which $0.6 million was attributable to noncontrolling interests. 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. 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. As of March 31, 2016 , the net assets of SEA-Vista were $194.1 million . During the three months ended March 31, 2016 , the net income of SEA-Vista was $13.9 million , of which $6.8 million was attributable to noncontrolling interests. During the three months ended March 31, 2015 , the net loss of SEA-Vista was $0.1 million . Illinois Corn Processing. ICP owns and operates an alcohol manufacturing, storage and distribution facility located in Pekin, IL. As of March 31, 2016 , the net assets of ICP were $64.6 million . During the three months ended March 31, 2016 , the net income of ICP was $1.4 million , of which $0.4 million was attributable to noncontrolling interests. 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.

Multiemployer Pension Plans

Multiemployer Pension Plans	3 Months Ended
	Mar. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Multiemployer Pension Plans	MULTI-EMPLOYER PENSION PLANS AMOPP. During the three months ended March 31, 2016 , the Company received notification from the AMOPP that the Company's withdrawal liability as of September 30, 2015 was $46.7 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, 2016 , 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, 2016
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, 2016 were as follows: Director stock awards granted 875 Employee Stock Purchase Plan (“ESPP”) shares issued 27,538 Restricted stock awards granted 132,758 Restricted stock awards canceled 900 Stock Option Activities: Outstanding as of December 31, 2015 1,690,899 Granted 46,165 Exercised (27,094 ) Forfeited (18,760 ) Expired (74,602 ) Outstanding as of March 31, 2016 1,616,608 Shares available for future grants and ESPP purchases as of March 31, 2016 651,493

Commitments And Contingencies

Commitments And Contingencies	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	COMMITMENTS AND CONTINGENCIES The Company's capital commitments as of March 31, 2016 by year of expected payment were as follows (in thousands): 2016 2017 2018 2019 Total Shipping Services $ 150,476 $ 22,630 $ — $ — $ 173,106 Offshore Marine Services 55,545 38,847 29,199 10,123 133,714 Inland River Services 29,060 28,510 — — 57,570 Illinois Corn Processing 3,399 — — — 3,399 Other 3 — — — 3 $ 238,483 $ 89,987 $ 29,199 $ 10,123 $ 367,792 Shipping Services' capital commitments included three U.S.-flag product tankers, one U.S.-flag chemical and petroleum articulated tug barge and two U.S.-flag harbor tugs. Offshore Marine Services' capital commitments included eight fast support vessels, four supply vessels, two specialty offshore support vessels and one wind farm utility vessel. Inland River Services' capital commitments included 50 dry-cargo barges, one inland river 30,000 barrel liquid tank barge and five inland river towboats. 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 " in the U.S. Gulf of Mexico on April 20, 2010, 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 was 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 taken under advisement. 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, had to 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 ("PSC") 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 the 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. On January 7, 2016, the Court issued an Order to Show Cause ("OSC") as to the B3 claims against the Clean-Up Responder Defendants, including ORM and NRC. The OSC ordered any plaintiff(s) opposed to the Court entering the proposed Order & Reasons ("O&R") attached to the OSC to show cause, in writing, on or before January 28, 2016 why the Court should not dismiss their B3 claim(s) with prejudice for the reasons set forth in the O&R. The O&R addressed the pending summary judgment motions and stated, among other things, why the Clean-Up Responder Defendants are entitled to derivative immunity under the Clean Water Act and discretionary function immunity under the Federal Tort Claims Act, and why plaintiffs’ claims are preempted by the implied conflict preemption doctrine. The O&R also discussed the results of the protocol delineated in the Court’s July 17, 2014 pretrial order and concluded with the dismissal of all but eleven plaintiffs’ B3 claims against the Clean-Up Responder Defendants with prejudice. Following the issuance of the OSC, ORM and NRC complied with the same notice requirements delineated in the July 17, 2014 pretrial order and, along with the PSC, submitted a joint certification to that effect on January 15, 2016. Eight individual plaintiffs submitted responses to the OSC by the January 28, 2016 deadline, and the Clean-Up Responder Defendants submitted a response thereto on February 4, 2016. On February 16, 2016, the Court issued an order overruling the objections relayed in the eight individual Plaintiffs’ responses to the OSC, and then entered a dismissal order nearly identical to the O&R. Accordingly, the final Order & Reasons entered on February 16, 2016 dismissed all but eleven B3 claims against ORM and NRC with prejudice, whether by joinder in the master complaint, individual complaint, or otherwise (the "B3 Dismissal Order"). The deadline for Plaintiffs to appeal the B3 Dismissal Order has passed and the Company is evaluating how this ruling will impact the individual civil actions discussed below. Moreover, on April 8, 2016, the Court entered an order establishing a summary judgment briefing schedule as to the remaining eleven B3 claimants. Such summary judgment motions are to be filed by the Clean-Up Responder Defendants, including ORM and NRC, on May 9, 2016, with opposition and reply briefing to follow. This summary judgment briefing schedule pertains to several individual civil actions discussed herein, including the Wunstell Action. 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 the remaining B3 claims, the Company does not expect they 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 were stayed upon consolidation with the MDL 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 was 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. On May 22, 2015, the employee filed an opposition to the Company's motion as well as a motion to be recognized as an opt-out plaintiff or extend the opt-out deadline in connection with the below-referenced Medical Settlement, and on May 29, 2015, the Company filed a reply brief in further support of its motion. On June 10, 2015, the Court granted the Company's motion for summary judgment, dismissing all of the employee's claims against the Company and/or the M/V Seacor Vanguard with prejudice, and denied the employee's May 22, 2015 motion regarding his opt-out position in connection with the Medical Settlement. Final judgments for all of the employee's claims were issued by the Court on June 17, 2015, and the employee filed his Notice of Appeal on July 7, 2015. Following the docketing of the employee’s appeals with the Fifth Circuit, the Company filed a motion to consolidate these appeals, which was granted on August 21, 2015. The employee filed his appellant brief in the consolidated appeal on October 23, 2015, the Company submitted its appellee brief on November 25, 2015, and the employee filed his reply brief on January 4, 2016. On April 6, 2016, the Fifth Circuit affirmed the district court's decision dismissing all of the employee's claims with prejiduce. 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 evaluating the impact of the B3 Dismissal Order and other developments in the MDL, including the settlements discussed below, on these individual actions. The Company is unable to estimate the potential exposure, if any, resulting from these matters, to the extent they remain viable, 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. The remainder of the aforementioned cross-claims in Transocean's limitation action remain 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 since they were consolidated with the MDL. The Company continues to evaluate the impact of the B3 Dismissal Order and other developments in the MDL, including the settlements discussed below, 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. 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 submitting claims in both settlements have passed. 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, 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. 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.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2016
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, 2015 . The following tables summarize the operating results, capital expenditures and assets of the Company's reportable segments. Offshore Marine Services $’000 Inland River Services $’000 Shipping Services $’000 ICP (1)(2) $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the three months ended March 31, 2016 Operating Revenues: External customers 59,853 39,028 57,055 49,609 8,383 — 213,928 Intersegment 26 586 — — 36 (648 ) — 59,879 39,614 57,055 49,609 8,419 (648 ) 213,928 Costs and Expenses: Operating 48,850 30,118 27,234 46,289 5,805 (828 ) 157,468 Administrative and general 12,398 3,912 6,918 656 4,223 7,597 35,704 Depreciation and amortization 14,838 7,137 6,562 1,053 455 944 30,989 76,086 41,167 40,714 47,998 10,483 7,713 224,161 Gains (Losses) on Asset Dispositions and Impairments, Net (380 ) 605 (6 ) — (2 ) — 217 Operating Income (Loss) (16,587 ) (948 ) 16,335 1,611 (2,066 ) (8,361 ) (10,016 ) Other Income (Expense): Derivative gains (losses), net 2,898 — — (187 ) — (91 ) 2,620 Foreign currency gains (losses), net (1,560 ) 1,437 (3 ) — (27 ) 190 37 Other, net 265 — 1 — — 2 268 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 2,161 (2,778 ) 26 — 542 — (49 ) Segment Profit (Loss) (12,823 ) (2,289 ) 16,359 1,424 (1,551 ) Other Income (Expense) not included in Segment Profit (Loss) (28,215 ) Less Equity Losses included in Segment Profit (Loss) 49 Loss Before Taxes and Equity Losses (35,306 ) Capital Expenditures 20,907 1,970 23,894 686 — (21 ) 47,436 As of March 31, 2016 Property and Equipment: Historical cost 1,099,063 379,310 451,347 51,341 3,053 31,091 2,015,205 Accumulated depreciation (557,968 ) (148,779 ) (240,652 ) (20,443 ) (2,613 ) (15,593 ) (986,048 ) 541,095 230,531 210,695 30,898 440 15,498 1,029,157 Construction in progress 117,809 9,136 357,296 2,031 — (1,800 ) 484,472 Held for sale equipment — 86,332 — — — — 86,332 Net property and equipment 658,904 325,999 567,991 32,929 440 13,698 1,599,961 Investments, at Equity, and Advances to 50% or Less Owned Companies 135,406 79,478 63,365 — 56,121 — 334,370 Inventories 3,199 1,268 544 13,325 95 — 18,431 Goodwill — 2,400 1,852 — 48,124 — 52,376 Intangible Assets 1,017 5,744 — — 18,989 — 25,750 Other current and long-term assets, excluding cash and near cash assets (3) 93,050 45,383 26,319 7,969 33,524 12,037 218,282 Segment Assets 891,576 460,272 660,071 54,223 157,293 Cash and near cash assets (3) 862,717 Total Assets 3,111,887 ______________________ (1) Operating revenues includes $46.6 million of tangible product sales and operating expenses includes $43.3 million of costs of goods sold. (2) Inventories includes raw materials of $2.5 million and work in process of $1.5 million . (3) Cash and near cash assets includes cash, cash equivalents, marketable securities, and construction reserve funds. Offshore Marine Services $’000 Inland River Services $’000 Shipping Services $’000 ICP (1)(2) $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the three months ended March 31, 2015 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 31, 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 Net property and equipment 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 2,053 272,310 Segment Assets 887,269 525,382 702,605 57,414 183,954 Cash and near cash assets (3) 792,438 Total Assets 3,169,951 ______________________ (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.

Basis of Presentation and Acc19

Basis of Presentation and Accounting Policy (Policy)	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Basis Of Consolidation	The condensed consolidated financial information for the three months ended March 31, 2016 and 2015 has been prepared by the Company and has not been audited by its independent registered certified 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, 2016 , its results of operations for the three months ended March 31, 2016 and 2015 , its comprehensive loss for the three months ended March 31, 2016 and 2015 , its changes in equity for the three months ended March 31, 2016 , and its cash flows for the three months ended March 31, 2016 and 2015 . 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, 2015 . 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, 2015 .
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, 2016 , deferred revenues of $6.8 million , included in other current liabilities in the accompanying condensed consolidated balance sheets, 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. The Company is vigorously defending its interest in connection with the bankruptcy filing; however, payments received under the Conveyance subsequent to May 19, 2012 are subject to creditors' claims in bankruptcy court. The Company will recognize revenues when reasonably assured of a judgment in its favor. 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, 2016 , 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 maintenance and repair costs and the costs of routine overhauls, drydockings and inspections performed on vessels and equipment are charged to operating expense as incurred. Expenditures that extend the useful life or improve the marketing and commercial characteristics of equipment as well as major renewals and improvements to other properties are capitalized. Certain interest costs incurred during the construction of equipment are capitalized as part of the assets’ carrying values and are amortized over such assets’ estimated useful lives. During the three months ended March 31, 2016 , capitalized interest totaled $5.5 million . EQUIPMENT ACQUISITIONS AND DISPOSITIONS During the three months ended March 31, 2016 , capital expenditures were $47.4 million . Equipment deliveries during the three months ended March 31, 2016 included one wind farm utility vessel. During the three months ended March 31, 2016 , the Company sold other property and equipment for net proceeds of $0.1 million in cash. In addition, the Company recognized previously deferred gains of $0.6 million . Held for sale equipment. On April 15, 2016, the Company sold 20 30,000 barrel tank barges, the rights to eight leased-in 30,000 barrel tank barges and 14 inland river towboats for $90.0 million . Included in the sold equipment are one 30,000 barrel tank barge and one towboat currently under construction. The Company is obligated to complete the construction of this equipment prior to delivery, and the estimated costs of completion are included in the Company's capital commitments (see Note 11).
Property, Plant and Equipment [Table Text Block]	As of March 31, 2016 , 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, 2016 and 2015 , the Company recognized impairment charges of $0.4 million and $6.6 million , respectively, related to long-lived assets held for use. The Company had previously identified indicators of impairment for certain of its offshore support vessel classes operated by Offshore Marine Services as a result of continued weak market conditions from the decline in oil and gas prices. These indicators may include a significant decrease in the market price of a long-lived asset or asset group, a significant adverse change in the extent or manner in which a long-lived asset or asset group is being used or in its physical condition, or a current period operating or cash flow loss combined with a history of operating or cash flow losses or a forecast that demonstrates continuing losses associated with the use of a long-lived asset or asset group. As a consequence, the Company estimated the undiscounted cash flows for those asset groups and determined that the carrying value of the long-lived assets would be recovered through the future operations of those asset groups. The preparation of the undiscounted cash flows required management to make certain estimates and assumptions on expected future rates per day worked and utilization levels of the vessel classes based on anticipated future offshore oil and gas exploration and production activity in the geographical regions where the Company operates. If difficult market conditions persist and an anticipated recovery is delayed beyond the Company's expectation, revisions to management's forecasts may result in the Company recording additional impairment charges related to its long-lived assets in future periods. Impairment of 50% or Less Owned Companies. Investments in 50% or less owned companies are reviewed periodically to assess whether there is an other-than-temporary decline in the fair value of the investment. An annual review is performed to consider, among other things, whether the carrying value of the investment is able to be recovered and whether or not the investee’s ability to sustain an earnings capacity would justify the carrying value of the investment. When the Company determines its investment in the 50% or less owned company is not recoverable or the decline in fair value is other-than-temporary, the investment is written down to fair value. Actual results may vary from the Company's estimates due to the uncertainty regarding the projected financial performance of 50% or less owned companies, the severity and expected duration of declines in value, and the available liquidity in the capital markets to support the continuing operations of the 50% or less owned company. During the three months ended March 31, 2016 and 2015 , the Company did not recognize any impairment charges related to its 50% or less owned companies.
Income Tax Disclosure [Text Block]	Income Taxes. During the three months ended March 31, 2016 , the Company's effective tax rate of 42.0% was primarily due to taxes not provided on income attributable to noncontrolling interests (see Note 8).
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 month ended March 31 was as follows (in thousands): 2016 2015 Balance at beginning of period $ 135,909 $ 159,911 Amortization of deferred gains included in operating expenses as a reduction to rental expense (5,658 ) (5,641 ) Amortization of deferred gains included in gains (losses) on asset dispositions and impairments, net (623 ) (1,048 ) Deferred gains on held for sale equipment (1,707 ) — Balance at end of period $ 127,921 $ 153,222
Schedule Of Deferred Gain Activity [Table Text Block]	Deferred gain activity related to these transactions for the three month ended March 31 was as follows (in thousands): 2016 2015 Balance at beginning of period $ 135,909 $ 159,911 Amortization of deferred gains included in operating expenses as a reduction to rental expense (5,658 ) (5,641 ) Amortization of deferred gains included in gains (losses) on asset dispositions and impairments, net (623 ) (1,048 ) Deferred gains on held for sale equipment (1,707 ) — Balance at end of period $ 127,921 $ 153,222
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss. The components of accumulated other comprehensive loss were as follows (in thousands): SEACOR Holdings Inc. Stockholders' Equity Noncontrolling Interests Foreign Currency Translation Adjustments Derivative Losses on Cash Flow Hedges, net Other Total Foreign Currency Translation Adjustments Other Other Comprehensive Loss December 31, 2015 $ (5,528 ) $ (116 ) $ 24 $ (5,620 ) $ (528 ) $ 16 Other comprehensive loss (1,689 ) (1,606 ) (3 ) (3,298 ) (179 ) (2 ) $ (3,479 ) Income tax benefit 591 562 1 1,154 — — 1,154 Three Months Ended March 31, 2016 $ (6,626 ) $ (1,160 ) $ 22 $ (7,764 ) $ (707 ) $ 14 $ (2,325 )
Earnings Per Common Share of SEACOR	Loss Per Share. Basic loss per common share of SEACOR is computed based on the weighted average number of common shares issued and outstanding during the relevant periods. Diluted loss per common share of SEACOR is 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 loss per common share of SEACOR were as follows (in thousands, except share data): Three Months Ended March 31, Net Loss attributable to SEACOR Average O/S Shares Per Share 2016 Basic Weighted Average Common Shares Outstanding $ (27,186 ) 16,817,368 $ (1.62 ) Effect of Dilutive Share Awards: Options and Restricted Stock (1) — — Convertible Notes (2) — — Diluted Weighted Average Common Shares Outstanding $ (27,186 ) 16,817,368 $ (1.62 ) 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 (3) — — Diluted Weighted Average Common Shares Outstanding $ (19,569 ) 17,777,725 $ (1.10 ) ______________________ (1) For the three months ended March 31, 2016 , and 2015 , diluted earnings per common share of SEACOR excluded 1,997,822 and 1,977,402 , 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, 2016 , diluted earnings per common share of SEACOR excluded 3,379,393 common shares issuable pursuant to the Company's 2.5% Convertible Senior Notes, 1,825,326 common shares issuable pursuant to the Company's 3.0% Convertible Senior Notes and 2,243,500 common shares issuable pursuant to the Company's 3.75% Subsidiary 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 , diluted earnings per common share of SEACOR excluded 4,200,525 common shares issuable pursuant to the Company's 2.5% Convertible Senior Notes and 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.
Schedule of Weighted Average Number of Shares [Table Text Block]	Computations of basic and diluted loss per common share of SEACOR were as follows (in thousands, except share data): Three Months Ended March 31, Net Loss attributable to SEACOR Average O/S Shares Per Share 2016 Basic Weighted Average Common Shares Outstanding $ (27,186 ) 16,817,368 $ (1.62 ) Effect of Dilutive Share Awards: Options and Restricted Stock (1) — — Convertible Notes (2) — — Diluted Weighted Average Common Shares Outstanding $ (27,186 ) 16,817,368 $ (1.62 ) 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 (3) — — Diluted Weighted Average Common Shares Outstanding $ (19,569 ) 17,777,725 $ (1.10 ) ______________________ (1) For the three months ended March 31, 2016 , and 2015 , diluted earnings per common share of SEACOR excluded 1,997,822 and 1,977,402 , 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, 2016 , diluted earnings per common share of SEACOR excluded 3,379,393 common shares issuable pursuant to the Company's 2.5% Convertible Senior Notes, 1,825,326 common shares issuable pursuant to the Company's 3.0% Convertible Senior Notes and 2,243,500 common shares issuable pursuant to the Company's 3.75% Subsidiary 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 , diluted earnings per common share of SEACOR excluded 4,200,525 common shares issuable pursuant to the Company's 2.5% Convertible Senior Notes and 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.
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 or 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 25, 2016, the FASB issued a comprehensive new leasing standard, which improves transparency and comparability among companies by requiring lessees to recognize a lease liability and a corresponding lease asset for virtually all lease contracts. It also requires additional disclosures about leasing arrangements. The new standard is effective for interim and annual periods beginning after December 15, 2018 and requires a modified retrospective approach to adoption. Early adoption is permitted. The Company has not yet determined what impact, if any, the adoption of the new standard will have on its consolidated financial position, results of operations or cash flows.

Derivative Instruments And He20

Derivative Instruments And Hedging Strategies Derivative Instruments, Gain (Loss) (Tables)	3 Months Ended
	Mar. 31, 2016
Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) [Table Text Block]	The Company recognized gains (losses) on derivative instruments not designated as hedging instruments for the three month ended March 31 as follows (in thousands): 2016 2015 Options on equities and equity indices $ 2,904 $ (1,374 ) Forward currency exchange, option and future contracts 45 (304 ) Interest rate swap agreements (6 ) (9 ) Commodity swap, option and future contracts: Exchange traded (187 ) (2,184 ) Non-exchange traded — 875 $ 2,756 $ (2,996 )

Noncontrolling Interests in S21

Noncontrolling Interests in Subsidiaries (Tables)	3 Months Ended
	Mar. 31, 2016
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, 2016 December 31, 2015 Offshore Marine Services: Windcat Workboats 25% $ 6,682 $ 7,484 Other 1.8 % – 30% 267 470 Inland River Services: Other 3.0 % – 51.8% 960 1,146 Shipping Services: Sea-Vista 49% 95,118 88,290 Illinois Corn Processing 30% 19,392 22,272 Other 5.0 % – 14.6% 483 457 $ 122,902 $ 120,119

Share Based Compensation (Table

Share Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2016
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, 2016 were as follows: Director stock awards granted 875 Employee Stock Purchase Plan (“ESPP”) shares issued 27,538 Restricted stock awards granted 132,758 Restricted stock awards canceled 900 Stock Option Activities: Outstanding as of December 31, 2015 1,690,899 Granted 46,165 Exercised (27,094 ) Forfeited (18,760 ) Expired (74,602 ) Outstanding as of March 31, 2016 1,616,608 Shares available for future grants and ESPP purchases as of March 31, 2016 651,493

Commitments And Contingencies C

Commitments And Contingencies Capital Commitments (Tables)	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Unrecorded Unconditional Purchase Obligations Disclosure [Table Text Block]	The Company's capital commitments as of March 31, 2016 by year of expected payment were as follows (in thousands): 2016 2017 2018 2019 Total Shipping Services $ 150,476 $ 22,630 $ — $ — $ 173,106 Offshore Marine Services 55,545 38,847 29,199 10,123 133,714 Inland River Services 29,060 28,510 — — 57,570 Illinois Corn Processing 3,399 — — — 3,399 Other 3 — — — 3 $ 238,483 $ 89,987 $ 29,199 $ 10,123 $ 367,792 Shipping Services' capital commitments included three U.S.-flag product tankers, one U.S.-flag chemical and petroleum articulated tug barge and two U.S.-flag harbor tugs. Offshore Marine Services' capital commitments included eight fast support vessels, four supply vessels, two specialty offshore support vessels and one wind farm utility vessel. Inland River Services' capital commitments included 50 dry-cargo barges, one inland river 30,000 barrel liquid tank barge and five inland river towboats.

Segment Information Segment Inf

Segment Information Segment Information (Tables)	3 Months Ended
	Mar. 31, 2016
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 Marine Services $’000 Inland River Services $’000 Shipping Services $’000 ICP (1)(2) $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the three months ended March 31, 2016 Operating Revenues: External customers 59,853 39,028 57,055 49,609 8,383 — 213,928 Intersegment 26 586 — — 36 (648 ) — 59,879 39,614 57,055 49,609 8,419 (648 ) 213,928 Costs and Expenses: Operating 48,850 30,118 27,234 46,289 5,805 (828 ) 157,468 Administrative and general 12,398 3,912 6,918 656 4,223 7,597 35,704 Depreciation and amortization 14,838 7,137 6,562 1,053 455 944 30,989 76,086 41,167 40,714 47,998 10,483 7,713 224,161 Gains (Losses) on Asset Dispositions and Impairments, Net (380 ) 605 (6 ) — (2 ) — 217 Operating Income (Loss) (16,587 ) (948 ) 16,335 1,611 (2,066 ) (8,361 ) (10,016 ) Other Income (Expense): Derivative gains (losses), net 2,898 — — (187 ) — (91 ) 2,620 Foreign currency gains (losses), net (1,560 ) 1,437 (3 ) — (27 ) 190 37 Other, net 265 — 1 — — 2 268 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 2,161 (2,778 ) 26 — 542 — (49 ) Segment Profit (Loss) (12,823 ) (2,289 ) 16,359 1,424 (1,551 ) Other Income (Expense) not included in Segment Profit (Loss) (28,215 ) Less Equity Losses included in Segment Profit (Loss) 49 Loss Before Taxes and Equity Losses (35,306 ) Capital Expenditures 20,907 1,970 23,894 686 — (21 ) 47,436 As of March 31, 2016 Property and Equipment: Historical cost 1,099,063 379,310 451,347 51,341 3,053 31,091 2,015,205 Accumulated depreciation (557,968 ) (148,779 ) (240,652 ) (20,443 ) (2,613 ) (15,593 ) (986,048 ) 541,095 230,531 210,695 30,898 440 15,498 1,029,157 Construction in progress 117,809 9,136 357,296 2,031 — (1,800 ) 484,472 Held for sale equipment — 86,332 — — — — 86,332 Net property and equipment 658,904 325,999 567,991 32,929 440 13,698 1,599,961 Investments, at Equity, and Advances to 50% or Less Owned Companies 135,406 79,478 63,365 — 56,121 — 334,370 Inventories 3,199 1,268 544 13,325 95 — 18,431 Goodwill — 2,400 1,852 — 48,124 — 52,376 Intangible Assets 1,017 5,744 — — 18,989 — 25,750 Other current and long-term assets, excluding cash and near cash assets (3) 93,050 45,383 26,319 7,969 33,524 12,037 218,282 Segment Assets 891,576 460,272 660,071 54,223 157,293 Cash and near cash assets (3) 862,717 Total Assets 3,111,887 ______________________ (1) Operating revenues includes $46.6 million of tangible product sales and operating expenses includes $43.3 million of costs of goods sold. (2) Inventories includes raw materials of $2.5 million and work in process of $1.5 million . (3) Cash and near cash assets includes cash, cash equivalents, marketable securities, and construction reserve funds. Offshore Marine Services $’000 Inland River Services $’000 Shipping Services $’000 ICP (1)(2) $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the three months ended March 31, 2015 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 31, 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 Net property and equipment 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 2,053 272,310 Segment Assets 887,269 525,382 702,605 57,414 183,954 Cash and near cash assets (3) 792,438 Total Assets 3,169,951 ______________________ (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.

Basis of Presentation and Acc25

Basis of Presentation and Accounting Policies Revenue Recognition (Details) $ in Millions	Mar. 31, 2016USD ($)
Offshore Marine Services [Member]
Deferred Revenue	$ 6.8

Basis of Presentation and Acc26

Basis of Presentation and Accounting Policies Property and Equipment (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)
Property, Plant and Equipment [Line Items]
Capitalized Interest Costs, Including Allowance for Funds Used During Construction	$ 5.5
Offshore Support Vessels [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	20 years
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 Acc27

Basis of Presentation and Accounting Policies Impairments of Long-Lived Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Accounting Policies [Abstract]
Asset Impairment Charges	$ 0.4	$ 6.6

Basis of Presentation and Acc28

Basis of Presentation and Accounting Policies Income Taxes (Details)	3 Months Ended
	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, Percent	42.00%

Basis of Presentation and Acc29

Basis of Presentation and Accounting Policies Deferred Gains (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Deferred Gains	$ 127,921	$ 153,222	$ 135,909	$ 159,911
Amortization of Deferred Gains	1,707	0
Operating Expense [Member]
Amortization of Deferred Gains	5,658	5,641
Gain (Loss) on Asset Dispositions and Impairments, Net [Member]
Amortization of Deferred Gains	$ 623	$ 1,048

Basis of Presentation and Acc30

Basis of Presentation and Accounting Policies Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	$ (6,626)		$ (5,528)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(1,160)		(116)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	22		24
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Parent	(1,689)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax, Portion Attributable to Parent	(1,606)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, Portion Attributable to Parent	(3)
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(3,298)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest	(179)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest	(2)
Other Comprehensive Income (Loss), before Tax	(3,479)	$ (3,983)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax, Portion Attributable to Parent	591
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax, Portion Attributable to Parent	562
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax, Portion Attributable to Parent	1
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	1,154
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	(1,154)	(1,255)
Accumulated Other Comprehensive Loss, Net of Tax	(7,764)		(5,620)
Other Comprehensive Income (Loss), Net of Tax	(2,325)	$ (2,728)
Non-Controlling Interests In Subsidiaries [Member]
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(707)		(528)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	14		$ 16
Other Comprehensive Income (Loss), Net of Tax	$ (181)

Basis of Presentation and Acc31

Basis of Presentation and Accounting Policies Earning Per Common Share (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Net Loss attributable to SEACOR Holdings Inc.	$ (27,186,000)	$ (19,569,000)
Dilutive Securities, Effect on Basic Earnings Per Share, Options and Restrictive Stock Units	0	0
Dilutive Securities, Effect on Basic Earnings Per Share, Dilutive Convertible Securities	0	0
Net Loss Available to Common Stockholders, Diluted	$ (27,186,000)	$ (19,569,000)
Weighted Average Number of Shares Outstanding, Basic	16,817,368	17,777,725
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	0	0
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities	0	0
Weighted Average Number of Shares Outstanding, Diluted	16,817,368	17,777,725
Basic Loss Per Common Share of SEACOR Holdings Inc.	$ (1.62)	$ (1.10)
Diluted Loss Per Common Share of SEACOR Holdings Inc.	$ (1.62)	$ (1.10)
Stock Compensation Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,997,822	1,977,402
Three Point Zero Percentage Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,825,326	1,825,326
Three Point Seven Five Percentage Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,243,500
Two Point Five Percentage Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	3,379,393	4,200,525
Three Point Seven Five Percentage Convertible Notes [Member]
Debt Instrument, Interest Rate, Stated Percentage	3.75%
Three Point Zero Percentage Convertible Notes [Member]
Debt Instrument, Interest Rate, Stated Percentage	3.00%	3.00%
Two Point Five Percentage Convertible Notes [Member]
Debt Instrument, Interest Rate, Stated Percentage	2.50%	2.50%

Equipment Acquisitions, Disposi

Equipment Acquisitions, Dispositions and Depreciation and Impairment Policies (Narrative) (Details) $ in Thousands	3 Months Ended
	Jun. 30, 2016USD ($)equipment	Mar. 31, 2016USD ($)equipment	Mar. 31, 2015USD ($)
Property, Plant and Equipment [Line Items]
Payments to Acquire Property, Plant, and Equipment | $		$ 47,436	$ 47,430
Sales Price Of Equipment | $		100
Amortization Of Deferred Gains Included In Gains On Asset Dispositions And Impairments, Net | $		$ 1,707	0
Wind Farm Utility Vessel [Member]
Property, Plant and Equipment [Line Items]
Number Of Equipments Delivered | equipment		1
Gain (Loss) on Asset Dispositions and Impairments, Net [Member]
Property, Plant and Equipment [Line Items]
Amortization Of Deferred Gains Included In Gains On Asset Dispositions And Impairments, Net | $		$ 623	$ 1,048
Subsequent Event [Member]
Property, Plant and Equipment [Line Items]
Sales Price Of Equipment | $	$ 90,000
Subsequent Event [Member] | Inland River Towboat [Member]
Property, Plant and Equipment [Line Items]
Number Of Equipments Sold | equipment	14
Number of Equipment Under Construction | equipment	1
Subsequent Event [Member] | Inland River Liquid Tank Barges - 30,000 Barrel [Member]
Property, Plant and Equipment [Line Items]
Number Of Equipments Sold | equipment	20
Number of Equipment Under Construction | equipment	1

Investments, At Equity, And A33

Investments, At Equity, And Advances To 50% Or Less Owned Companies (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)
Schedule Of Equity Method Investments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 2.7
Allocable Share of Uncalled Capital	1.9
Falcon Global [Member]
Schedule Of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions	4.3
SCFCo Holdings [Member]
Schedule Of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions	0.3
Outstanding Working Capital Advances At End Of Period	26.1
Sea-Access [Member]
Schedule Of Equity Method Investments [Line Items]
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital	1.5
Partners' Capital Account, Return of Capital	1.1
Seajon [Member]
Schedule Of Equity Method Investments [Line Items]
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital	0.6
Avion Pacific Limited [Member]
Schedule Of Equity Method Investments [Line Items]
Outstanding Working Capital Advances At End Of Period	3
Payments for Advance to Affiliate	(3)
VA&E [Member]
Schedule Of Equity Method Investments [Line Items]
Outstanding Working Capital Advances At End Of Period	3.6
Line of Credit Facility, Maximum Borrowing Capacity	6
Proceeds from Unsecured Lines of Credit	2.1
Repayments of Long-term Lines of Credit	(5.5)
Other Corporate Joint Ventures [Member]
Schedule Of Equity Method Investments [Line Items]
Payments for Advance to Affiliate	0.4
Other Offshore Marine Services Joint Ventures [Member]
Schedule Of Equity Method Investments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 55.2

Long-Term Debt (Details)

Long-Term Debt (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Debt Instrument [Line Items]
Common Stock, par value		$ 0.01		$ 0.01
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 165,900
Debt extinguishment gains		3,223	$ 0
Letters of Credit Outstanding, Amount		25,000
Guarantor Obligations, Maximum Exposure, Undiscounted		$ 2,700
Seven Point Three Seven Five Percentage Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		7.375%
Debt Instrument, Repurchased Face Amount		$ 13,900
Debt Instrument, Repurchase Amount		11,900
Debt extinguishment gains		$ 1,800
Three Point Zero Percentage Convertible Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.00%	3.00%
Two Point Five Percentage Convertible Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		2.50%	2.50%
Debt Instrument, Repurchased Face Amount		$ 20,200
Debt Instrument, Repurchase Amount		18,900
Debt extinguishment gains		1,400
Other Debt Obligations [Member]
Debt Instrument [Line Items]
Repayments of long-term debt		2,200
Proceeds from Issuance of Debt		7,400
Debt Issuance Cost		100
Sea-Vista [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Proceeds from Lines of Credit		5,000
Line of Credit Facility, Current Borrowing Capacity		82,000
Sea-Vista [Member] | Term A-1 Loan [Member]
Debt Instrument [Line Items]
Repayments of long-term debt		1,000
Illinois Corn Processing LLC [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity		15,500
Long-term Debt [Member] | Two Point Five Percentage Convertible Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Repurchase Amount		17,500
Additional Paid-In Capital [Member] | Two Point Five Percentage Convertible Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Repurchase Amount		$ 1,400
Subsequent Event [Member] | Sea-Vista [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Proceeds from Lines of Credit	$ 32,000

Derivative Instruments And He35

Derivative Instruments And Hedging Strategies (Fair Values Of Derivative Instruments) (Details) $ in Thousands	Mar. 31, 2016USD ($)
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 427
Derivative Liability	1,875
Options on equities and equity indices
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	0
Derivative Liability	250
Foreign currency exchange, option and future contracts
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	228
Derivative Liability	0
Interest rate swap agreements
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	0
Derivative Liability	212
Commodity swap, option and future contracts, exchange traded
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	199
Derivative Liability	$ 1,413

Derivative Instruments And He36

Derivative Instruments And Hedging Strategies (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Derivative [Line Items]
Derivative losses on cash flow hedges	$ (1,830)	$ (397)
Cash Flow Hedging [Member] | Mexmar [Member]
Derivative [Line Items]
Fixed interest rate range, minimum	1.71%
Fixed interest rate range, maximum	2.05%
Derivative, Notional Amount	$ 114,700
Cash Flow Hedging [Member] | Sea-Cat Crewzer II [Member]
Derivative [Line Items]
Fixed interest rate	1.52%
Derivative, Notional Amount	$ 25,000
Cash Flow Hedging [Member] | Sea Cat Crewzer [Member]
Derivative [Line Items]
Fixed interest rate	1.52%
Derivative, Notional Amount	$ 22,200
Cash Flow Hedging [Member] | Seajon [Member]
Derivative [Line Items]
Fixed interest rate	2.79%
Derivative, Notional Amount	$ 32,100
Three Point Seven Five Percentage Convertible Notes [Member]
Derivative [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.75%
Embedded Derivative, Fair Value of Embedded Derivative Liability	$ 5,747		$ 5,611
Embedded Derivative, Gain on Embedded Derivative	$ 136

Derivative Instruments And He37

Derivative Instruments And Hedging Strategies (Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Derivative [Line Items]
Derivative gains (losses), net	$ 2,756	$ (2,996)
Options on equities and equity indices
Derivative [Line Items]
Derivative gains (losses), net	2,904	(1,374)
Forward Currency Exchange, Option And Future Contracts [Member]
Derivative [Line Items]
Derivative gains (losses), net	45	(304)
Interest rate swap agreements
Derivative [Line Items]
Derivative gains (losses), net	(6)	(9)
Commodity swap, option and future contracts, exchange traded
Derivative [Line Items]
Derivative gains (losses), net	(187)	(2,184)
Commodity swap, option and future contracts, non-exchange traded
Derivative [Line Items]
Derivative gains (losses), net	0	$ 875
Not Designated as Hedging Instrument [Member] | Forward Currency Exchange, Option And Future Contracts [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 2,000
Not Designated as Hedging Instrument [Member] | Interest rate swap agreements
Derivative [Line Items]
Derivative, Fixed Interest Rate	3.00%
Derivative, Notional Amount	$ 5,800
Not Designated as Hedging Instrument [Member] | OSV Partners [Member] | Interest rate swap agreements
Derivative [Line Items]
Derivative, Notional Amount	$ 41,800
Derivative, Lower Fixed Interest Rate Range	1.89%
Derivative, Higher Fixed Interest Rate Range	2.27%
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	$ 81,200
Not Designated as Hedging Instrument [Member] | Falcon Global [Member] | Interest rate swap agreements
Derivative [Line Items]
Derivative, Fixed Interest Rate	2.06%
Derivative, Notional Amount	$ 62,500

Fair Value Measurements (Financ

Fair Value Measurements (Financial Assets And Liabilities Measured At Fair Value On Recurring Basis) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Construction Reserve Funds	$ 255,350		$ 255,408
Exchange Option Liability on Subsidiary Convertible Senior Notes	5,747		$ 5,611
Marketable security (losses), net	(24,500)	$ (200)
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	110,894
Derivative instruments (included in other receivables)	199
Construction Reserve Funds	255,350
Short sales of marketable securities	5,053
Derivative instruments (included in other current liabilities)	1,663
Exchange Option Liability on Subsidiary Convertible Senior Notes	0
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)	228
Construction Reserve Funds	0
Short sales of marketable securities	0
Derivative instruments (included in other current liabilities)	212
Exchange Option Liability on Subsidiary Convertible Senior Notes	0
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	0
Short sales of marketable securities	0
Derivative instruments (included in other current liabilities)	0
Exchange Option Liability on Subsidiary Convertible Senior Notes	$ 5,747

Fair Value Measurements (Estima

Fair Value Measurements (Estimated Fair Value Of Other Financial Assets And Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, Carrying Amount	$ 496,473	$ 530,009	$ 448,011	$ 434,183
Investments, at cost, in 50% or less owned companies (included in other assets), Carrying Amount	16,045
Notes receivable from other business ventures (included in other receivables and other assets), Carrying Amount	22,574
Long-term debt, including current portion, Carrying Amount	1,054,019
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, Fair Value Disclosure	496,473
Debt Instrument, Fair Value Disclosure	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, Fair Value Disclosure	0
Debt Instrument, Fair Value Disclosure	1,019,076
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, Fair Value Disclosure	0
Debt Instrument, Fair Value Disclosure	$ 0
Two Point Five Percentage Convertible Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.50%		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%		3.00%

Stock Repurchases (Details)

Stock Repurchases (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 165.9
Restricted Stock [Member]
Treasury Stock, Shares, Acquired	47,455
Treasury Stock, Value, Acquired, Cost Method	$ 2.4
Seven Point Three Seven Five Percentage Senior Notes [Member]
Debt Instrument, Interest Rate, Stated Percentage	7.375%
Three Point Zero Percentage Convertible Notes [Member]
Debt Instrument, Interest Rate, Stated Percentage	3.00%	3.00%
Two Point Five Percentage Convertible Notes [Member]
Debt Instrument, Interest Rate, Stated Percentage	2.50%	2.50%

Noncontrolling Interests in S41

Noncontrolling Interests in Subsidiaries (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	$ 122,902		$ 120,119
Net Income (Loss)	(20,524)	$ (17,901)
Net Income (Loss) Attributable to Noncontrolling Interest	$ 6,662	1,668
Illinois Corn Processing LLC [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries			22,272
Offshore Marine Services [Member] | Windcat Workboats Ltd. [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	25.00%
Noncontrolling interests in subsidiaries	$ 6,682		7,484
Assets, Net	26,700
Net Income (Loss)	(2,500)	2,300
Net Income (Loss) Attributable to Noncontrolling Interest	(600)
Offshore Marine Services [Member] | Other Offshore Marine Services Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	267		470
Inland River Services [Member] | Other Inland River Services Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	$ 960		1,146
Shipping Services [Member] | Sea-Vista [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	49.00%
Noncontrolling interests in subsidiaries	$ 95,118		88,290
Assets, Net	194,100
Net Income (Loss)	$ 13,900	(100)
Illinois Corn Processing LLC [Member] | Illinois Corn Processing LLC [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	30.00%
Noncontrolling interests in subsidiaries	$ 19,392
Assets, Net	64,600
Net Income (Loss)	1,400	4,100
Net Income (Loss) Attributable to Noncontrolling Interest	400	$ 1,200
Other Segments [Member] | Other Noncontrolling Interests [Member]
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	$ 483		$ 457
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	5.00%
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	30.00%
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	14.60%

Multiemployer Pension Plans (De

Multiemployer Pension Plans (Details) $ in Millions	Sep. 30, 2015USD ($)
American Maritime Officers Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and other postretirement benefit plans, withdrawal liability	$ 46.7

Share Based Compensation (Share

Share Based Compensation (Share Based Compensation Plans) (Details) shares in Thousands	3 Months Ended
	Mar. 31, 2016shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Director stock awards granted	875
Employee Stock Purchase Plan shares issued	27,538
Restricted stock awards granted	132,758
Restricted stock awards forfeited	900
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Stock Options, Outstanding as of December 31, 2015	1,690,899
Stock Option, Granted	46,165
Stock Option, Exercised	(27,094)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period	18,760
Stock Option, Expired	(74,602)
Stock Options, Outstanding as of March 31, 2016	1,616,608
Shares available for future grants and ESPP purchases as of March 31, 2016	651,493

Commitments And Contingencies (

Commitments And Contingencies (Narrative) (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2016USD ($)equipment	Dec. 31, 2013claim	Dec. 31, 2012claim	Dec. 31, 2011claim	Dec. 31, 2010claim
Loss Contingencies [Line Items]
Total unfunded capital commitments	$ 367,792,000
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	238,483,000
Unrecorded Unconditional Purchase Obligation, Due in Second Years	89,987,000
Unrecorded Unconditional Purchase Obligation, Due in Third Year	29,199,000
Unrecorded Unconditional Purchase Obligation Due in Fourth Year	$ 10,123,000
Wunstell Action [Member]
Loss Contingencies [Line Items]
Claims Filed | claim					2
Master Complaints [Member]
Loss Contingencies [Line Items]
Claims Filed | claim					1
Loss Contingency, Number of Plaintiffs	11
Multi-district Litigation [Member]
Loss Contingencies [Line Items]
Claims Filed | claim				10
Darnell Alexander [Member]
Loss Contingencies [Line Items]
Claims Filed | claim			410	117
Abney Litigation [Member]
Loss Contingencies [Line Items]
Claims Filed | claim			668
Abood Litigation [Member]
Loss Contingencies [Line Items]
Claims Filed | claim		174
U.S.-flag Product Tankers [Member]
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	3
U.S. Flag Articulated Tug-Barge [Member]
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	1
U.S.-flag Harbor Tugs [Member]
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	2
Offshore Support Vessels Fast Support [Member]
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	8
Offshore Support Vessels Supply [Member]
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity	0
Offshore Support Vessels Specialty [Member]
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity	2
Wind Farm Utility Vessel [Member]
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	1
Inland River Dry Cargo Barges [Member]
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity	50
Inland River Liquid Tank Barges - 30,000 Barrel [Member]
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	1
Inland River Towboats [Member]
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	5
Shipping Services [Member]
Loss Contingencies [Line Items]
Total unfunded capital commitments	$ 173,106,000
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	150,476,000
Unrecorded Unconditional Purchase Obligation, Due in Second Years	22,630,000
Unrecorded Unconditional Purchase Obligation, Due in Third Year	0
Unrecorded Unconditional Purchase Obligation Due in Fourth Year	0
Offshore Marine Services [Member]
Loss Contingencies [Line Items]
Total unfunded capital commitments	133,714,000
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	55,545,000
Unrecorded Unconditional Purchase Obligation, Due in Second Years	38,847,000
Unrecorded Unconditional Purchase Obligation, Due in Third Year	29,199,000
Unrecorded Unconditional Purchase Obligation Due in Fourth Year	10,123,000
Inland River Services [Member]
Loss Contingencies [Line Items]
Total unfunded capital commitments	57,570,000
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	29,060,000
Unrecorded Unconditional Purchase Obligation, Due in Second Years	28,510,000
Unrecorded Unconditional Purchase Obligation, Due in Third Year	0
Unrecorded Unconditional Purchase Obligation Due in Fourth Year	0
Illinois Corn Processing LLC [Member]
Loss Contingencies [Line Items]
Total unfunded capital commitments	3,399,000
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	3,399,000
Unrecorded Unconditional Purchase Obligation, Due in Second Years	0
Unrecorded Unconditional Purchase Obligation, Due in Third Year	0
Unrecorded Unconditional Purchase Obligation Due in Fourth Year	0
Other Segments [Member]
Loss Contingencies [Line Items]
Total unfunded capital commitments	3,000
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	3,000
Unrecorded Unconditional Purchase Obligation, Due in Second Years	0
Unrecorded Unconditional Purchase Obligation, Due in Third Year	0
Unrecorded Unconditional Purchase Obligation Due in Fourth Year	$ 0

Segment Information (Operating

Segment Information (Operating Results, Capital Expenditures And Assets By Reportable Segments) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Operating Revenues	$ 213,928,000	$ 260,644,000
Costs and Expenses [Abstract]
Administrative and general	35,704,000	38,887,000
Depreciation and amortization	30,989,000	31,430,000
Total costs and expenses	224,161,000	269,465,000
Gains (Losses) on Asset Dispositions and Impairments, Net	217,000	(4,846,000)
Operating Income (Loss)	(10,016,000)	(13,667,000)
Other Income and Expenses [Abstract]
Derivative gains (losses), net	2,620,000	(2,996,000)
Foreign currency gains (losses), net	37,000	(1,993,000)
Other Nonoperating Income (Expense)	268,000	(44,000)
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	(49,000)	3,899,000
Loss Before Taxes and Equity Earnings	(35,306,000)	(33,754,000)
Capital Expenditures	47,436,000	47,430,000
Property, Plant and Equipment, Gross	2,015,205,000		$ 2,123,201,000
Accumulated depreciation	(986,048,000)		(994,181,000)
Construction in progress	484,472,000		454,605,000
Held for sale equipment	86,332,000		0
Net property and equipment	1,599,961,000		1,583,625,000
Inventories	18,431,000		24,768,000
Goodwill	52,376,000		52,340,000
Intangible Assets, Net	25,750,000		26,392,000
Total assets	3,111,887,000	3,169,951,000	$ 3,185,419,000
Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	59,853,000	93,421,000
Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	39,028,000	55,836,000
Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	57,055,000	51,407,000
Illinois Corn Processing LLC [Member]
Segment Reporting Information [Line Items]
Operating Revenues	49,609,000	39,598,000
Other Income and Expenses [Abstract]
Sales Revenue, Goods, Net	46,600,000	37,200,000
Cost of Goods Sold	43,300,000	30,700,000
Inventory, Raw Materials	2,500,000	1,600,000
Inventory, Work in Process	1,500,000	1,700,000
Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues	8,383,000	20,382,000
Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	0	0
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues	213,928,000	260,644,000
Costs and Expenses [Abstract]
Operating Expenses	157,468,000	199,148,000
Administrative and general	35,704,000	38,887,000
Depreciation and amortization	30,989,000	31,430,000
Total costs and expenses	224,161,000	269,465,000
Gains (Losses) on Asset Dispositions and Impairments, Net	217,000	(4,846,000)
Operating Income (Loss)	(10,016,000)	(13,667,000)
Other Income and Expenses [Abstract]
Derivative gains (losses), net	2,620,000	(2,996,000)
Foreign currency gains (losses), net	37,000	(1,993,000)
Other Nonoperating Income (Expense)	268,000	(44,000)
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	(49,000)	3,899,000
Capital Expenditures	47,436,000	47,430,000
Property, Plant and Equipment, Gross	2,015,205,000	2,083,035,000
Accumulated depreciation	(986,048,000)	(918,769,000)
Property, Plant and Equipment, Net In Service	1,029,157,000	1,164,266,000
Construction in progress	484,472,000	339,390,000
Held for sale equipment	86,332,000
Net property and equipment	1,599,961,000	1,503,656,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	334,370,000	483,748,000
Inventories	18,431,000	23,156,000
Goodwill	52,376,000	62,688,000
Intangible Assets, Net	25,750,000	31,955,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	218,282,000	272,310,000
Operating Segments [Member] | Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	59,879,000	93,456,000
Costs and Expenses [Abstract]
Operating Expenses	48,850,000	74,355,000
Administrative and general	12,398,000	13,559,000
Depreciation and amortization	14,838,000	15,366,000
Total costs and expenses	76,086,000	103,280,000
Gains (Losses) on Asset Dispositions and Impairments, Net	(380,000)	(6,649,000)
Operating Income (Loss)	(16,587,000)	(16,473,000)
Other Income and Expenses [Abstract]
Derivative gains (losses), net	2,898,000	(9,000)
Foreign currency gains (losses), net	(1,560,000)	(17,000)
Other Nonoperating Income (Expense)	265,000	(146,000)
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	2,161,000	2,975,000
Segment Profit (Loss)	(12,823,000)	(13,670,000)
Capital Expenditures	20,907,000	24,128,000
Property, Plant and Equipment, Gross	1,099,063,000	1,062,061,000
Accumulated depreciation	(557,968,000)	(504,926,000)
Property, Plant and Equipment, Net In Service	541,095,000	557,135,000
Construction in progress	117,809,000	92,873,000
Held for sale equipment	0
Net property and equipment	658,904,000	650,008,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	135,406,000	118,253,000
Inventories	3,199,000	5,360,000
Goodwill	0	13,367,000
Intangible Assets, Net	1,017,000	1,515,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	93,050,000	98,766,000
Total assets	891,576,000	887,269,000
Operating Segments [Member] | Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	39,614,000	56,607,000
Costs and Expenses [Abstract]
Operating Expenses	30,118,000	41,513,000
Administrative and general	3,912,000	3,884,000
Depreciation and amortization	7,137,000	6,889,000
Total costs and expenses	41,167,000	52,286,000
Gains (Losses) on Asset Dispositions and Impairments, Net	605,000	1,803,000
Operating Income (Loss)	(948,000)	6,124,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	0	82,000
Foreign currency gains (losses), net	1,437,000	(1,121,000)
Other Nonoperating Income (Expense)	0	0
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	(2,778,000)	(274,000)
Segment Profit (Loss)	(2,289,000)	4,811,000
Capital Expenditures	1,970,000	3,916,000
Property, Plant and Equipment, Gross	379,310,000	485,881,000
Accumulated depreciation	(148,779,000)	(162,581,000)
Property, Plant and Equipment, Net In Service	230,531,000	323,300,000
Construction in progress	9,136,000	25,605,000
Held for sale equipment	86,332,000
Net property and equipment	325,999,000	348,905,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	79,478,000	101,344,000
Inventories	1,268,000	2,171,000
Goodwill	2,400,000	2,502,000
Intangible Assets, Net	5,744,000	6,692,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	45,383,000	63,768,000
Total assets	460,272,000	525,382,000
Operating Segments [Member] | Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	57,055,000	51,407,000
Costs and Expenses [Abstract]
Operating Expenses	27,234,000	37,131,000
Administrative and general	6,918,000	6,289,000
Depreciation and amortization	6,562,000	6,735,000
Total costs and expenses	40,714,000	50,155,000
Gains (Losses) on Asset Dispositions and Impairments, Net	(6,000)	0
Operating Income (Loss)	16,335,000	1,252,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	0	0
Foreign currency gains (losses), net	(3,000)	(12,000)
Other Nonoperating Income (Expense)	1,000	29,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	26,000	1,141,000
Segment Profit (Loss)	16,359,000	2,410,000
Capital Expenditures	23,894,000	18,180,000
Property, Plant and Equipment, Gross	451,347,000	454,039,000
Accumulated depreciation	(240,652,000)	(219,662,000)
Property, Plant and Equipment, Net In Service	210,695,000	234,377,000
Construction in progress	357,296,000	218,729,000
Held for sale equipment	0
Net property and equipment	567,991,000	453,106,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	63,365,000	221,658,000
Inventories	544,000	977,000
Goodwill	1,852,000	1,852,000
Intangible Assets, Net	0	146,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	26,319,000	24,866,000
Total assets	660,071,000	702,605,000
Operating Segments [Member] | Illinois Corn Processing LLC [Member]
Segment Reporting Information [Line Items]
Operating Revenues	49,609,000	39,598,000
Costs and Expenses [Abstract]
Operating Expenses	46,289,000	33,118,000
Administrative and general	656,000	562,000
Depreciation and amortization	1,053,000	980,000
Total costs and expenses	47,998,000	34,660,000
Gains (Losses) on Asset Dispositions and Impairments, Net	0	0
Operating Income (Loss)	1,611,000	4,938,000
Other Income and Expenses [Abstract]
Derivative gains (losses), net	(187,000)	(828,000)
Foreign currency gains (losses), net	0	0
Other Nonoperating Income (Expense)	0	0
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	0
Segment Profit (Loss)	1,424,000	4,110,000
Capital Expenditures	686,000	776,000
Property, Plant and Equipment, Gross	51,341,000	47,256,000
Accumulated depreciation	(20,443,000)	(16,468,000)
Property, Plant and Equipment, Net In Service	30,898,000	30,788,000
Construction in progress	2,031,000	1,494,000
Held for sale equipment	0
Net property and equipment	32,929,000	32,282,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	0	0
Inventories	13,325,000	13,711,000
Goodwill	0	0
Intangible Assets, Net	0	0
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	7,969,000	11,421,000
Total assets	54,223,000	57,414,000
Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues	8,419,000	20,452,000
Costs and Expenses [Abstract]
Operating Expenses	5,805,000	13,830,000
Administrative and general	4,223,000	7,136,000
Depreciation and amortization	455,000	500,000
Total costs and expenses	10,483,000	21,466,000
Gains (Losses) on Asset Dispositions and Impairments, Net	(2,000)	0
Operating Income (Loss)	(2,066,000)	(1,014,000)
Other Income and Expenses [Abstract]
Derivative gains (losses), net	0	(776,000)
Foreign currency gains (losses), net	(27,000)	(40,000)
Other Nonoperating Income (Expense)	0	8,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	542,000	57,000
Segment Profit (Loss)	(1,551,000)	(1,765,000)
Capital Expenditures	0	3,000
Property, Plant and Equipment, Gross	3,053,000	3,521,000
Accumulated depreciation	(2,613,000)	(3,236,000)
Property, Plant and Equipment, Net In Service	440,000	285,000
Construction in progress	0	234,000
Held for sale equipment	0
Net property and equipment	440,000	519,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	56,121,000	42,493,000
Inventories	95,000	937,000
Goodwill	48,124,000	44,967,000
Intangible Assets, Net	18,989,000	23,602,000
Other Current And Long-Term Assets, Excluding Cash And Near Cash Assets	33,524,000	71,436,000
Total assets	157,293,000	183,954,000
Operating Segments [Member] | Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	(648,000)	(876,000)
Costs and Expenses [Abstract]
Operating Expenses	(828,000)	(799,000)
Administrative and general	7,597,000	7,457,000
Depreciation and amortization	944,000	960,000
Total costs and expenses	7,713,000	7,618,000
Gains (Losses) on Asset Dispositions and Impairments, Net	0	0
Operating Income (Loss)	(8,361,000)	(8,494,000)
Other Income and Expenses [Abstract]
Derivative gains (losses), net	(91,000)	(1,465,000)
Foreign currency gains (losses), net	190,000	(803,000)
Other Nonoperating Income (Expense)	2,000	65,000
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	0	0
Capital Expenditures	(21,000)	427,000
Property, Plant and Equipment, Gross	31,091,000	30,277,000
Accumulated depreciation	(15,593,000)	(11,896,000)
Property, Plant and Equipment, Net In Service	15,498,000	18,381,000
Construction in progress	(1,800,000)	455,000
Held for sale equipment	0
Net property and equipment	13,698,000	18,836,000
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	12,037,000	2,053,000
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	(26,000)	35,000
Intersegment Eliminations [Member] | Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues	(586,000)	771,000
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	(36,000)	70,000
Intersegment Eliminations [Member] | Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	648,000	(876,000)
Segment Reconciling Items [Member]
Other Income and Expenses [Abstract]
Other Income (Expense) not included in Segment Profit (Loss)	28,215,000	15,054,000
Less Equity Earnings included in Segment Profit (Loss)	49,000	(3,899,000)
Cash And Near Cash Assets	$ 862,717,000	$ 792,438,000

Uncategorized Items - ckh-20160

Label	Element	Value
AOCI Attributable to Parent [Member]
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt, Subsequent Adjustments	us-gaap_AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebtSubsequentAdjustments	$ 0
Additional Paid-in Capital [Member]
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt, Subsequent Adjustments	us-gaap_AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebtSubsequentAdjustments	(898,000)
Common Stock [Member]
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt, Subsequent Adjustments	us-gaap_AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebtSubsequentAdjustments	0
Noncontrolling Interest [Member]
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt, Subsequent Adjustments	us-gaap_AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebtSubsequentAdjustments	0
Retained Earnings [Member]
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt, Subsequent Adjustments	us-gaap_AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebtSubsequentAdjustments	0
Treasury Stock [Member]
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt, Subsequent Adjustments	us-gaap_AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebtSubsequentAdjustments	$ 0