Seacor (CKH) 10-K 30 Mar 17 2016 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2016	Mar. 28, 2017	Jun. 30, 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-K
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		17,405,946
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 914,009,247

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 399,644	$ 530,009
Restricted cash	3,711	0
Marketable securities	116,276	138,200
Receivables:
Trade, net of allowance for doubtful accounts of $5,201 and $2,483 in 2016 and 2015, respectively	162,880	159,076
Other	56,287	27,217
Inventories	16,773	24,768
Prepaid expenses and other	7,230	8,627
Total current assets	762,801	887,897
Property and Equipment:
Historical cost	2,194,023	2,123,201
Accumulated depreciation	1,008,867	994,181
Property, Plant and Equipment, Net In Service	1,185,156	1,129,020
Construction in progress	370,512	454,605
Net property and equipment	1,555,668	1,583,625
Investments, at Equity, and Advances to 50% or Less Owned Companies	313,772	331,103
Construction Reserve Funds	153,962	255,408
Goodwill	32,758	52,340
Intangible Assets, Net	20,078	26,392
Other Assets	23,282	48,654
Total Assets	2,862,321	3,185,419
Current Liabilities:
Current portion of long-term debt	183,602	35,531
Accounts payable and accrued expenses	90,702	71,952
Accrued wages and benefits	17,989	21,938
Accrued interest	5,503	5,774
Accrued income taxes	5,835	5,801
Short sales of marketable securities	1,274	4,827
Accrued capital, repair and maintenance expenditures	23,665	11,585
Deferred revenues	6,953	6,953
Other current liabilities	34,426	35,799
Total current liabilities	369,949	200,160
Long-Term Debt	848,771	1,034,859
Exchange Option Liability on Subsidiary Convertible Senior Notes	19,436	5,611
Deferred Income Taxes	288,601	389,988
Deferred Gains and Other Liabilities	139,296	163,862
Total liabilities	1,666,053	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; 37,939,032 and 37,684,829 shares issued in 2016 and 2015, respectively	379	377
Additional paid-in capital	1,518,635	1,505,942
Retained earnings	910,723	1,126,620
Shares held in treasury of 20,538,327 and 20,529,929 in 2016 and 2015, respectively, at cost	1,357,331	1,356,499
Accumulated other comprehensive loss, net of tax	(11,514)	(5,620)
Stockholders' equity attributable to SEACOR Holdings Inc.	1,060,892	1,270,820
Noncontrolling interests in subsidiaries	135,376	120,119
Total equity	1,196,268	1,390,939
Liabilities and stockholders' equity, total	$ 2,862,321	$ 3,185,419

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Trade receivables, allowance for doubtful accounts	$ 8,347,300.39	$ 2,483,172.89
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	37,939,032	37,684,829
Treasury stock, shares	20,538,327	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

Consolidated Statements Of Inco

Consolidated Statements Of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Operating Revenues	$ 830,985	$ 1,054,736	$ 1,319,394
Costs and Expenses:
Operating	597,813	748,605	909,372
Administrative and general	138,581	156,611	164,938
Depreciation and amortization	124,933	125,987	131,819
Total costs and expenses	861,327	1,031,203	1,206,129
Gains (Losses) on Asset Dispositions and Impairments, Net	(142,205)	(2,408)	51,978
Operating Income (Loss)	(172,547)	21,125	165,243
Other Income (Expense):
Interest income	19,339	20,020	19,662
Interest expense	(49,726)	(43,297)	(43,632)
Debt extinguishment gains (losses), net	5,184	(28,497)	0
Marketable security gains (losses), net	(32,199)	(74)	28,760
Derivative losses, net	(10,225)	(2,096)	(3,902)
Foreign currency losses, net	(1,868)	(4,752)	(6,335)
Other, net	(20,206)	6,773	3,439
Nonoperating Income (Expense)	(89,701)	(51,923)	(2,008)
Income (Loss) Before Income Tax Expense (Benefit) and Equity in Earnings (Losses) of 50% or Less Owned Companies	(262,248)	(30,798)	163,235
Income Tax Expense (Benefit):
Current	1,894	26,568	72,261
Deferred	(95,724)	(37,930)	(17,064)
Income Tax Expense (Benefit)	(93,830)	(11,362)	55,197
Income (Loss) Before Equity in Earnings (Losses) of 50% or Less Owned Companies	(168,418)	(19,436)	108,038
Equity in Earnings (Losses) of 50% or Less Owned Companies	(27,354)	(40,414)	16,309
Net Income (Loss)	(195,772)	(59,850)	124,347
Net Income Attributable to Noncontrolling Interests in Subsidiaries	20,125	8,932	24,215
Net Income (Loss) attributable to SEACOR Holdings Inc.	$ (215,897)	$ (68,782)	$ 100,132
Basic Earnings (Loss) Per Common Share of SEACOR Holdings Inc.	$ (12.76)	$ (3.94)	$ 5.18
Diluted Earnings (Loss) Per Common Share of SEACOR Holdings Inc.	$ (12.76)	$ (3.94)	$ 4.71
Weighted Average Common Shares Outstanding:
Basic Weighted Average Common Shares Outstanding	16,914,928	17,446,137	19,336,280
Diluted Weighted Average Common Shares Outstanding	16,914,928	17,446,137	25,765,325

Consolidated Statements Of Chan

Consolidated Statements 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]
Total equity	$ 1,425,428	$ 372	$ 1,394,621	$ 1,095,270	$ (1,088,219)	$ (1,192)	$ 24,576
Issuance of common stock:
Employee Stock Purchase Plan	2,165	0	0	0	2,165	0	0
Exercise of stock options	6,875	1	6,874	0	0	0	0
Director stock awards	210	0	210	0	0	0	0
Restricted stock and restricted stock units	(222)	(2)	(199)	0	(21)	0	0
Purchase of treasury shares	(197,336)	0	0	0	(197,336)	0	0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	15,119	0	15,119	0	0	0	0
Cancellation of restricted stock	0	0	107	0	107	0	0
Purchase of subsidiary shares from noncontrolling interests, net of tax	(3,110)	0	(1,242)	0	0	0	(1,868)
Issuance of noncontrolling interests	152,423	0	74,810	0	0	0	77,613
Dividends paid to noncontrolling interests	6,070	0	0	0	0	0	6,070
Comprehensive income:
Net Income attributable to SEACOR Holdings Inc.	100,132	0	0		0	0
Net Income (Loss) Attributable to Noncontrolling Interest	24,215
Net Income (Loss)	124,347
Other Comprehensive Loss, Net of Tax	(2,786)	0	0	0	0	(2,313)	(473)
Total equity	1,517,487	375	1,490,698	1,195,402	(1,283,476)	(3,505)	117,993
Employee Stock Purchase Plan	2,298	0	0	0	2,298	0	0
Exercise of stock options	1,948	1	1,947	0	0	0	0
Director stock awards	234	0	234	0	0	0	0
Restricted stock and restricted stock units	(123)	(1)	(145)	0	(21)	0	0
Purchase of conversion option in convertible debt, net of tax	1,938	0	1,938	0	0	0	0
Purchase of treasury shares	(75,342)	0	0	0	(75,342)	0	0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	14,649	0	14,649	0	0	0	0
Purchase of subsidiary shares from noncontrolling interests, net of tax	497	0	497	0	0	0	0
Disposition of subsidiary with noncontrolling interests	(1,578)	0	0	0	0	0	(1,578)
Issuance of noncontrolling interests	400	0	0	0	0	0	400
Dividends paid to noncontrolling interests	5,199	0	0	0	0	0	5,199
Net Income attributable to SEACOR Holdings Inc.	(68,782)	0	0		0	0
Net Income (Loss) Attributable to Noncontrolling Interest	8,932
Net Income (Loss)	(59,850)
Other Comprehensive Loss, Net of Tax	(2,544)	0	0	0	0	(2,115)	(429)
Total equity	1,390,939	377	1,505,942	1,126,620	(1,356,499)	(5,620)	120,119
Employee Stock Purchase Plan	1,726	0	0	0	1,726	0	0
Exercise of stock options	4,368	1	4,367	0	0	0	0
Director stock awards	186	0	186	0	0	0	0
Restricted stock and restricted stock units	(1,179)	(1)	(1,180)	0	0	0	0
Purchase of conversion option in convertible debt, net of tax	(4,793)	0	(4,793)	0	0	0	0
Purchase of treasury shares	(2,396)	0	0	0	(2,396)	0	0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	13,951	0	13,951	0	0	0	0
Cancellation of restricted stock	0	0	162	0	162	0	0
Dividends paid to noncontrolling interests	3,753	0	0	0	0	0	3,753
Net Income attributable to SEACOR Holdings Inc.	(215,897)	0	0		0	0
Net Income (Loss) Attributable to Noncontrolling Interest	20,125
Net Income (Loss)	(195,772)
Other Comprehensive Loss, Net of Tax	(7,009)	0	0	0	0	(5,894)	(1,115)
Total equity	$ 1,196,268	$ 379	$ 1,518,635	$ 910,723	$ (1,357,331)	$ (11,514)	$ 135,376

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash Flows from Operating Activities:
Net Income (Loss)	$ (195,772)	$ (59,850)	$ 124,347
Adjustments to reconcile income to net cash provided by operating activities:
Depreciation and amortization	124,933	125,987	131,819
Amortization of deferred gains on sale and leaseback transactions	23,272	22,521	18,847
Debt discount and issuance cost amortization, net	23,393	19,785	18,542
Amortization of share awards	13,951	14,649	15,119
Director stock awards	190	242	211
Bad debt expense	7,054	842	2,618
(Gains) Losses on asset dispositions and impairments, net	(142,205)	(2,408)	51,978
Debt extinguishment (gains) losses, net	5,184	(28,497)	0
Marketable security (gains) losses, net	(32,199)	(74)	28,760
Purchases of marketable securities	22,997	72,080	15,810
Proceeds from sale of marketable securities	9,169	91,333	6,802
Derivative losses, net	(10,225)	(2,096)	(3,902)
Cash settlements on derivative transactions, net	1,804	(359)	5,703
Foreign currency losses, net	(1,868)	(4,752)	(6,335)
Deferred income tax benefit	(95,724)	(37,930)	(17,064)
Equity in (earnings) losses of 50% or less owned companies, net of tax	27,354	40,414	(16,309)
Dividends received from 50% or less owned companies	5,939	15,249	9,290
Other, net	20,590	0	7,286
Changes in operating assets and liabilities:
(Increase) decrease in receivables	24,205	(74,830)	(7,514)
Increase in prepaid expenses and other assets	1,012	11,220	4,696
Increase (decrease) in accounts payable, accrued expenses and other liabilities	2,055	(46,759)	16,764
Net cash provided by operating activities	51,155	171,157	191,382
Cash Flows from Investing Activities:
Purchases of property and equipment	358,413	295,930	360,637
Cash settlements on derivative transactions, net	373	0	0
Proceeds from disposition of property and equipment	184,947	95,460	254,763
Investments in and advances to 50% or less owned companies	24,957	56,188	90,815
Return of investments and advances of 50% or less owned companies	9,519	61,479	36,311
Net repayments (advances) on revolving credit line to 50% or less owned companies	(2,397)	3,495	0
(Issuances of) payments received on third party leases and notes receivable, net	(2,583)	1,241	(8,437)
Net (increase) decrease in restricted cash	3,436	(16,435)	4,260
Net (increase) decrease in construction reserve funds and title XI reserve funds	(101,446)	(22,614)	16,283
Business acquisitions, net of cash acquired	20,539	0	35,000
Net cash used in investing activities	(111,992)	(158,384)	(224,358)
Cash Flows from Financing Activities:
Payments on long-term debt and capital lease obligations	195,751	233,259	35,444
Net payments under inventory financing arrangements	0	(2,661)	(4,240)
Proceeds from Issuance of long-term debt, net of offering costs	137,326	400,115	26,916
Purchase of conversion option in convertible debt	(7,374)	(2,982)	0
Common stock acquired for treasury	2,396	75,342	197,336
Proceeds and tax benefits from share award plans	4,911	4,094	9,240
Purchase of subsidiary shares from noncontrolling interests	0	0	2,090
Issuance of noncontrolling interests, net of issue costs	0	400	151,849
Dividends paid to noncontrolling interests, net	(3,753)	(5,199)	(6,070)
Net cash provided by (used in) financing activities	(67,037)	85,166	(57,175)
Effects of Exchange Rate Changes on Cash and Cash Equivalents	(2,491)	(2,113)	(3,101)
Net Increase (Decrease) in Cash and Cash Equivalents	(130,365)	95,826	(93,252)
Cash and Cash Equivalents, Beginning of Year	530,009	434,183	527,435
Cash and Cash Equivalents, End of Year	$ 399,644	$ 530,009	$ 434,183

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income Statement - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net Income (Loss)	$ (195,772)	$ (59,850)	$ 124,347
Foreign currency translation losses	(10,490)	(3,592)	(4,265)
Reclassification of foreign currency translation (gains) losses to foreign currency losses, net	74	21	(165)
Derivative losses on cash flow hedges	(2,537)	(1,304)	(140)
Other	(44)	42	28
Other Comprehensive Loss, before Tax	(10,183)	(3,683)	(4,031)
Income tax benefit	3,174	1,139	1,245
Other Comprehensive Loss, Net of Tax	(7,009)	(2,544)	(2,786)
Comprehensive Income (Loss)	(202,781)	(62,394)	121,561
Comprehensive Income attributable to Noncontrolling Interests in Subsidiaries	19,010	8,503	23,742
Comprehensive Income (Loss) attributable to SEACOR Holdings Inc.	(221,791)	(70,897)	97,819
Interest Expense [Member]
Reclassification of derivative losses on cash flow hedges to equity in earnings (losses) of 50% or less owned companies	(18)	0	0
Equity Method Investments [Member]
Reclassification of derivative losses on cash flow hedges to equity in earnings (losses) of 50% or less owned companies	$ 2,796	$ 1,150	$ 511

Nature Of Operations And Accoun

Nature Of Operations And Accounting Policies	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Nature Of Operations And Accounting Policies	1. NATURE OF OPERATIONS AND ACCOUNTING POLICIES Nature of Operations and Segmentation. SEACOR Holdings Inc. (“SEACOR”) and its subsidiaries (collectively referred to as the “Company”) are in the business of owning, operating, investing in and marketing equipment, primarily in the offshore oil and gas, shipping and logistics industries. Accounting standards require public business enterprises to report information about each of their operating business segments that exceed certain quantitative thresholds or meet certain other reporting requirements. Operating business segments have been defined as a component of an enterprise about which separate financial information is available and is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. Certain reclassifications of prior year information have been made to conform to the current year’s reportable segment presentation (see Note 17) as a result of Witt O’Brien’s, LLC (“Witt O’Brien’s”) meeting certain quantitative thresholds in 2016. The Company has identified the following reporting segments: Offshore Marine Services. Offshore Marine Services operates a diverse fleet of support vessels primarily servicing major integrated national and international oil companies, large independent oil and gas exploration and production companies and emerging independent companies. These vessels deliver cargo and personnel to offshore installations; provide field security services; handle anchors and mooring equipment required to tether rigs to the seabed; tow rigs and assist in placing them on location and moving them between regions; and carry and launch equipment such as remote operated vehicles or “ROVs” used underwater in drilling and well installation, maintenance, inspection and repair. In addition, Offshore Marine Services' vessels provide accommodations for technicians and specialists, and provide standby safety support and emergency response services. Offshore Marine Services also operates a fleet of liftboats in the U.S. Gulf of Mexico that primarily support well intervention, work-over, decommissioning and diving operations. In non-oil and gas industry activity, Offshore Marine Services operates vessels primarily used to move personnel and supplies to offshore wind farms in Europe. Offshore Marine Services contributed 26% , 35% and 40% of consolidated operating revenues in 2016 , 2015 and 2014 , respectively. Inland River Services. Inland River Services operates domestic river transportation equipment used for moving agricultural and industrial commodities and containers on the U.S. Inland River Waterways, primarily the Mississippi River, Illinois River, Tennessee River, Ohio River and their tributaries and the Gulf Intracoastal Waterways. Internationally, Inland River Services has liquid tank barge operations on the Magdalena River in Colombia primarily transporting petroleum products and dry-cargo barge operations on the Parana-Paraguay River Waterways in Brazil, Bolivia, Paraguay, Argentina and Uruguay primarily transporting agricultural and industrial commodities. In addition to its primary barge and towboat businesses, Inland River Services also operates and invests in high-speed multi-modal terminal facilities for both dry and liquid commodities; barge fleeting locations in various areas of the U.S. Inland River Waterways; a broad range of service facilities including machine shop and the repair and drydocking of barges and towboats at strategic locations on the U.S. Inland River Waterways; and a transshipment terminal at the Port of Ibicuy, Argentina. Inland River Services contributed 20% , 22% and 19% of consolidated operating revenues in 2016 , 2015 and 2014 , respectively. Shipping Services. Shipping Services operates a diversified fleet of U.S.-flag marine transportation related assets, including its 51% controlling interest (see Note 12) in certain subsidiaries (collectively “SEA-Vista”) that operate product tankers servicing the U.S. coastwise trade of crude oil, petroleum and chemical products, and including its harbor tugs servicing vessels docking in U.S. Gulf and East Coast ports. Additional services include liner and short-sea transportation to and from ports in Florida, Puerto Rico, the Bahamas and the Western Caribbean, a terminal support and bunkering operation in St. Eustatius, a U.S.-flag articulated tug and dry bulk barge operating on the Great Lakes, a U.S.-flag offshore tug and technical ship management services for third party vessel owners. Shipping Services contributed 28% , 21% and 16% of consolidated operating revenues in 2016 , 2015 and 2014 , respectively. Illinois Corn Processing. Illinois Corn Processing, LLC (“ICP”) operates a single-site alcohol manufacturing, storage and distribution facility located in Pekin, Illinois and is a leading producer of alcohol used in the food, beverage, industrial and petrochemical end-markets. As co-products of its manufacturing process, ICP additionally produces Dried Distillers Grains with Solubles (“DDGS”) primarily used for animal feed and produces non-food grade Corn Oil primarily used for feedstock in biodiesel production. The Company owns a 70% interest in ICP (see Note 12). ICP contributed 21% , 16% and 18% of consolidated operating revenues in 2016 , 2015 and 2014 . Witt O’Brien’s. Witt O’Brien’s provides resilience solutions for key areas of critical infrastructure, including, but not limited to, government, energy, transportation, healthcare and education, in the United States and abroad. Witt O’Brien’s protects and enhances its customers’ enterprise value by strengthening their ability to prepare for, respond to and recover from natural and man-made disasters, including hurricanes, infectious disease, terrorism, cyber breaches, oil spills, shipping incidents and other disruptions. Witt O’Brien’s contributed 5% , 5% and 2% of consolidated operating revenues in 2016 , 2015 and 2014 . Other. The Company also has activities that are referred to and described under Other, which primarily include lending and leasing activities and noncontrolling investments in various other businesses, primarily industrial aviation services businesses in Asia and an agricultural commodity trading and logistics business that is primarily focused on the global origination, trading and merchandising of sugar. Basis of Consolidation. The consolidated financial statements include the accounts of SEACOR and its controlled subsidiaries. Control is generally deemed to exist if the Company has greater than 50% of the voting rights of a subsidiary. All significant intercompany accounts and transactions are eliminated in consolidation. Noncontrolling interests in consolidated subsidiaries are included in the consolidated balance sheets as a separate component of equity. The Company reports consolidated net income inclusive of both the Company’s and the noncontrolling interests’ share, as well as the amounts of consolidated net income (loss) attributable to each of the Company and the noncontrolling interests. If a subsidiary is deconsolidated upon a change in control, any retained noncontrolled equity investment in the former controlled subsidiary is measured at fair value and a gain or loss is recognized in net income (loss) based on such fair value. If a subsidiary is consolidated upon a change in control, any previous noncontrolled equity investment in the subsidiary is measured at fair value and a gain or loss is recognized based on such fair value. The Company employs the equity method of accounting for investments in 50% or less owned companies that it does not control but has the ability to exercise significant influence over the operating and financial policies of the business venture. Significant influence is generally deemed to exist if the Company has between 20% and 50% of the voting rights of a business venture but may exist when the Company’s ownership percentage is less than 20%. In certain circumstances, the Company may have an economic interest in excess of 50% but may not control and consolidate the business venture. Conversely, the Company may have an economic interest less than 50% but may control and consolidate the business venture. The Company reports its investments in and advances to these business ventures in the accompanying consolidated balance sheets as investments, at equity, and advances to 50% or less owned companies. The Company reports its share of earnings or losses from investments in 50% or less owned companies in the accompanying consolidated statements of income (loss) as equity in earnings (losses) of 50% or less owned companies, net of tax. The Company employs the cost method of accounting for investments in 50% or less owned companies it does not control or exercise significant influence. These investments in private companies are carried at cost and are adjusted only for capital distributions and other-than-temporary declines in fair value. Use of Estimates. The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Such estimates include those related to deferred revenues, allowance for doubtful accounts, useful lives of property and equipment, impairments, income tax provisions and certain accrued liabilities. Actual results could differ from those estimates and those differences may be material. Revenue Recognition. The Company recognizes revenue when it is realized or realizable and earned. Revenue is realized or realizable and earned when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price to the buyer is fixed or determinable, and collectability is reasonably assured. Revenue that does not meet these criteria is deferred until the criteria are met. Deferred revenues for the years ended December 31 were as follows (in thousands): 2016 2015 2014 Balance at beginning of year $ 6,953 $ 6,794 $ 6,592 Revenues deferred during the year — 159 202 Balance at end of year $ 6,953 $ 6,953 $ 6,794 As of December 31, 2016 , deferred revenues of $6.8 million 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. The Company’s Offshore Marine Services segment earns and recognizes revenues primarily from the time charter and bareboat charter of vessels to customers based upon daily rates of hire. Under a time charter, Offshore Marine Services provides a vessel to a customer and is responsible for all operating expenses, typically excluding fuel. Under a bareboat charter, Offshore Marine Services provides the vessel to the customer and the customer assumes responsibility for all operating expenses and risk of operation. Vessel charters may range from several days to several years. Revenues from time charters and bareboat charters are recognized as services are provided. In the U.S. Gulf of Mexico, time charter durations and rates are typically established in the context of master service agreements that govern the terms and conditions of charter. The Company’s Inland River Services segment earns and recognizes revenues primarily from the time charter and bareboat charter of equipment to customers and from voyage affreightment contracts whereby customers are charged an established rate per ton to transport cargo from point to point. Under a time charter, Inland River Services provides equipment to a customer and is responsible for all operating expenses, typically excluding fuel. Under a bareboat charter, Inland River Services provides the equipment to the customer and the customer assumes responsibility for all operating expenses and risk of operation. These charters typically range from one to six years and revenues from these charters are recognized as services are provided on a per day basis. Revenues from voyage affreightment contracts are generally recognized over the progress of the voyage while the related costs are expensed as incurred. Certain of Inland River Services’ barges are operated in barge pools with other barges owned by third parties from whom Inland River Services earns and recognizes a management fee as the services are rendered. Pursuant to the pooling agreements, operating revenues and expenses of participating barges are combined and the net results are allocated on a pro-rata basis based on the number of barge days contributed by each participant. In addition, revenues are earned from equipment chartered to third parties and from the storage and demurrage of cargoes associated with affreightment activities. In both of these cases, revenues are recognized as services are rendered. Inland River Services’ tank farm and handling facility earns revenues through rental and throughput charges. Rental revenues are recognized ratably over the rental period while throughput charges are recognized as product volume moves through the facility. The Company’s Shipping Services segment earns revenue from the time charter, bareboat charter and voyage charter of vessels, contracts of affreightment, ship assist services, transporting third party freight and ship management agreements with vessel owners. Under a time charter, Shipping Services provides a vessel to a customer and is responsible for all operating expenses, typically excluding fuel. Under a bareboat charter, Shipping Services provides the vessel to a customer and the customer assumes responsibility for all operating expenses and risk of operation. Revenues from time charters and bareboat charters are recognized as services are provided. Voyage contracts are contracts to carry cargoes on a single voyage basis regardless of time to complete. Contracts of affreightment are contracts for cargoes that are committed on a multi-voyage basis for various periods of time with minimum and maximum cargo tonnages specified over the period at a fixed or escalating rate per ton. Revenues for voyage contracts and contracts of affreightment are recognized over the progress of the voyage while the related costs are expensed as incurred. Ship assist services are provided by the Company’s harbor towing fleet to dock and undock vessels in various ports in the U.S. Gulf of Mexico and Atlantic Coast. Revenues from ship assist services are recognized as the services are performed. Revenues from transporting freight are recognized as third party freight is transported to various destinations, typically determined by a tariff based on weight and voyage length, which is usually one to eight days. Ship management agreements typically provide for technical services over a specified period of time, typically a year or more. Revenues from ship management agreements are recognized ratably over the service period. ICP earns revenues from the sale of alcohol and co-products. Revenues and related costs from these sales are recorded when title transfers to the buyer. Witt O’Brien’s earns revenues primarily from emergency response and debris management incidents, retainer and consulting services. Emergency response and debris management revenues are recognized as services are provided. Revenues from short term remediation services and longer term customer staff augmentation services for remediation and claims management are dependent on the magnitude and number of incidents. Retainer agreements with vessel and facility owners and operators generally have evergreen terms and are typically invoiced on an annual basis. Such retainer fees are generally recognized ratable over the term of the coverage period. Consulting services are performed in accordance with retainer agreements or specific contract terms. Revenues are recognized based on contractual terms, generally on a time and material basis with revenues recognized as the services are provided or on a fixed fee basis with revenues and expenses recognized upon completion of the contract or specific task. Cash Equivalents. The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. Cash equivalents consist of U.S treasury securities, money market instruments, time deposits and overnight investments. Restricted Cash. Restricted cash primarily related to cash collateral for letters of credit and banking facility requirements. Marketable Securities. Marketable equity securities with readily determinable fair values and debt securities are reported in the accompanying consolidated balance sheets as marketable securities. These investments are stated at fair value, as determined by their market observable prices, with both realized and unrealized gains and losses reported in the accompanying consolidated statements of income (loss) as marketable security gains (losses), net. Short sales of marketable securities are stated at fair value in the accompanying consolidated balance sheets with both realized and unrealized gains and losses reported in the accompanying consolidated statements of income (loss) as marketable security gains (losses), net. Long and short marketable security positions are primarily in energy, marine, transportation and other related businesses. Marketable securities are classified as trading securities for financial reporting purposes with gains and losses reported as operating activities in the accompanying consolidated statements of cash flows. The Company’s most significant marketable security position is its investment in 9,177,135 shares of Dorian LPG Ltd. (“Dorian”), a publicly traded company listed on the New York Stock Exchange under the symbol “LPG” (see Note 4). Dorian’s closing share price was $8.21 and $11.77 as of December 31, 2016 and 2015, respectively. The Company’s cost basis in Dorian is $13.66 per share. Trade Receivables. Customers of Offshore Marine Services are primarily major integrated oil companies, large independent oil and gas exploration and production companies and emerging independent companies. Customers of Inland River Services are primarily major agricultural companies, major integrated oil companies, iron ore producers and industrial companies. Customers of Shipping Services are primarily multinational oil and gas companies, refining companies, oil trading companies and large industrial consumers of crude and petroleum. Customers of ICP are primarily alcohol trading companies, industrial manufacturers, major agricultural companies, major integrated oil companies, and manufacturers in the food, beverage and household products industries. Customers of the Company’s other business activities primarily include industrial companies and distributors. All customers are granted credit on a short-term basis and related credit risks are considered minimal. The Company routinely reviews its trade receivables and makes provisions for probable doubtful accounts; however, those provisions are estimates and actual results could differ from those estimates and those differences may be material. Trade receivables are deemed uncollectible and removed from accounts receivable and the allowance for doubtful accounts when collection efforts have been exhausted. Derivative Instruments. The Company accounts for derivatives through the use of a fair value concept whereby all of the Company’s derivative positions are stated at fair value in the accompanying consolidated balance sheets. Realized and unrealized gains and losses on derivatives not designated as hedges are reported in the accompanying consolidated statements of income (loss) as derivative losses, net. Realized and unrealized gains and losses on derivatives designated as fair value hedges are recognized as corresponding increases or decreases in the fair value of the underlying hedged item to the extent they are effective, with any ineffective portion reported in the accompanying consolidated statements of income (loss) as derivative losses, net. Realized and unrealized gains and losses on derivatives designated as cash flow hedges are reported as a component of other comprehensive income (loss) in the accompanying consolidated statements of comprehensive income (loss) to the extent they are effective and reclassified into earnings on the same line item associated with the hedged transaction and in the same period the hedged transaction affects earnings. Any ineffective portions of cash flow hedges are reported in the accompanying consolidated statements of income (loss) as derivative losses, net. Realized and unrealized gains and losses on derivatives designated as cash flow hedges that are entered into by the Company’s 50% or less owned companies are also reported as a component of the Company’s other comprehensive income (loss) in proportion to the Company’s ownership percentage, with reclassifications and ineffective portions being included in equity in earnings (losses) of 50% or less owned companies, net of tax, in the accompanying consolidated statements of income (loss). Concentrations of Credit Risk. The Company is exposed to concentrations of credit risk associated with its cash and cash equivalents, construction reserve funds and derivative instruments. The Company minimizes its credit risk relating to these positions by monitoring the financial condition of the financial institutions and counterparties involved and by primarily conducting business with large, well-established financial institutions and diversifying its counterparties. The Company does not currently anticipate nonperformance of its significant counterparties. The Company is also exposed to concentrations of credit risk relating to its receivables due from customers in the industries described above. The Company does not generally require collateral or other security to support its outstanding receivables. The Company minimizes its credit risk relating to receivables by performing ongoing credit evaluations and, to date, credit losses have not been material. Inventories. Inventories are stated at the lower of cost (using the first-in, first-out and average cost methods) or market. Inventories consist primarily of fuel and fuel oil in the Company’s Offshore Marine Services, Shipping Services and Inland River Services segments. Inventories in ICP consist primarily of corn, high quality alcohol and fuel alcohol. The Company records write-downs, as needed, to adjust the carrying amount of inventories to the lower of cost or market. During the years ended December 31, 2016 , 2015 and 2014 , the Company recorded market write-downs of $2.7 million , $3.0 million and $0.4 million , respectively. 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 typically based upon a newly built asset being placed into service and represents the point at which it is typically not justifiable for the Company to continue to operate the asset in the same or similar manner. From time to time, the Company may acquire older assets that have already exceeded the Company’s useful life policy, in which case the Company depreciates such assets based on its best estimate of remaining useful life, typically the next survey or certification date. As of December 31, 2016 , the estimated useful life (in years) of each of the Company’s major classes of new equipment was as follows: Offshore support vessels (excluding wind farm utility) 20 Wind farm utility vessels 10 Inland river dry-cargo and deck barges 20 Inland river liquid tank barges 25 Inland river towboats and harbor boats 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”). The Company’s major classes of property and equipment as of December 31 were as follows (in thousands): Historical Cost (1) Accumulated Depreciation Net Book Value 2016 Offshore Marine Services: Anchor handling towing supply $ 228,857 $ (183,757 ) $ 45,100 Fast support 251,415 (72,599 ) 178,816 Supply 96,774 (58,028 ) 38,746 Standby safety 109,436 (88,020 ) 21,416 Specialty 45,765 (24,063 ) 21,702 Liftboats 104,356 (45,447 ) 58,909 Wind farm utility 60,671 (29,019 ) 31,652 Machinery and spares 32,921 (20,008 ) 12,913 Other (2) 28,564 (19,678 ) 8,886 958,759 (540,619 ) 418,140 Inland River Services: Dry-cargo barges 246,237 (97,602 ) 148,635 Liquid tank barges 16,114 (1,982 ) 14,132 Towboats 14,675 (1,320 ) 13,355 Harbor boats 17,338 (5,715 ) 11,623 Specialty and deck barges 12,292 (4,869 ) 7,423 Terminal and fleeting facilities 94,913 (48,981 ) 45,932 Other (2) 18,145 (6,658 ) 11,487 419,714 (167,127 ) 252,587 Shipping Services: Product tankers - U.S.-flag 546,019 (189,536 ) 356,483 Harbor and offshore tugs - U.S.-flag 72,877 (34,606 ) 38,271 Harbor tugs - Foreign-flag 29,689 (9,480 ) 20,209 Ocean liquid tank barges - U.S.-flag 39,238 (11,604 ) 27,634 Short-sea container\RORO - Foreign-flag 20,954 (6,774 ) 14,180 Other (2) 18,825 (6,004 ) 12,821 727,602 (258,004 ) 469,598 Illinois Corn Processing: Manufacturing facilities 55,028 (23,689 ) 31,339 Land 1,680 — 1,680 56,708 (23,689 ) 33,019 Witt O’Brien’s: Other (2) 1,559 (1,244 ) 315 Corporate and Eliminations: Other (2) 29,681 (18,184 ) 11,497 $ 2,194,023 $ (1,008,867 ) $ 1,185,156 ______________________ (1) Includes property and equipment acquired in business acquisitions at acquisition date fair value, and net of the impact of recognized impairment charges. (2) Includes land and buildings, leasehold improvements, fixed-wing aircraft, vehicles and other property and equipment. Historical Cost (1) Accumulated Depreciation Net Book Value 2015 Offshore Marine Services: Anchor handling towing supply $ 301,707 $ (168,534 ) $ 133,173 Fast support 222,720 (61,515 ) 161,205 Supply 139,315 (80,862 ) 58,453 Standby Safety 141,864 (113,136 ) 28,728 Specialty 46,522 (21,224 ) 25,298 Liftboats 122,764 (36,154 ) 86,610 Wind farm utility 66,950 (26,773 ) 40,177 Machinery and spares 34,116 (19,480 ) 14,636 Other (2) 26,661 (19,284 ) 7,377 1,102,619 (546,962 ) 555,657 Inland River Services: Dry-cargo barges 226,916 (86,068 ) 140,848 Liquid tank barges 61,175 (14,638 ) 46,537 Towboats 67,265 (15,670 ) 51,595 Harbor boats 10,206 (5,136 ) 5,070 Specialty and deck barges 12,293 (3,992 ) 8,301 Terminal and fleeting facilities 90,379 (40,890 ) 49,489 Other (2) 16,910 (4,877 ) 12,033 485,144 (171,271 ) 313,873 Shipping Services: Product tankers - U.S.-flag 271,141 (168,838 ) 102,303 Harbor and offshore tugs - U.S.-flag 72,073 (37,418 ) 34,655 Harbor tugs - Foreign-flag 29,689 (8,291 ) 21,398 Ocean liquid tank barges - U.S.-flag 39,238 (10,175 ) 29,063 Short-sea container\RORO - Foreign-flag 20,954 (5,369 ) 15,585 Other (2) 21,049 (8,985 ) 12,064 454,144 (239,076 ) 215,068 Illinois Corn Processing: Manufacturing facilities 45,576 (19,390 ) 26,186 Land 1,680 — 1,680 47,256 (19,390 ) 27,866 Witt O’Brien’s: Other (2) 3,338 (2,834 ) 504 Corporate and Eliminations: Other (2) 30,700 (14,648 ) 16,052 $ 2,123,201 $ (994,181 ) $ 1,129,020 ______________________ (1) Includes property and equipment acquired in business acquisitions at acquisition date fair value, and net of the impact of recognized impairment charges. (2) Includes land and buildings, leasehold improvements, fixed-wing aircraft, vehicles and other property and equipment. Depreciation expense totaled $122.5 million , $122.9 million and $127.6 million in 2016 , 2015 and 2014 , respectively. 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. Capitalized interest totaled $18.5 million , $18.5 million and $17.0 million in 2016 , 2015 and 2014 , respectively. Intangible Assets. The Company’s intangible assets primarily arose from business acquisitions (see Note 2) and consist of non-compete agreements, trademarks and tradenames, customer relationships, software and technology, and acquired contractual rights. These intangible assets are amortized over their estimated useful lives ranging from two to ten years. During the years ended December 31, 2016 , 2015 , and 2014 , the Company recognized amortization expense of $2.5 million , $3.1 million and $4.3 million , respectively. The Company’s intangible assets by type were as follows (in thousands): Trademark/ Tradenames Customer Relationships Software/ Technology Acquired Contractual Rights Total Gross Carrying Value Year Ended December 31, 2014 $ 10,681 $ 48,570 $ 1,652 $ 2,985 $ 63,888 Purchase price adjustments to acquired intangible assets (1,024 ) (2,133 ) — — (3,157 ) Foreign currency translation — — — (78 ) (78 ) Fully amortized intangible assets (4,737 ) (22,700 ) — — (27,437 ) Year Ended December 31, 2015 4,920 23,737 1,652 2,907 33,216 Acquired intangible assets — 1,598 — 5,500 7,098 Foreign currency translation — — — 9 9 Impairment of intangible assets (1,596 ) (8,128 ) (1,220 ) — (10,944 ) Fully amortized intangible assets — — (432 ) — (432 ) Year Ended December 31, 2016 $ 3,324 $ 17,207 $ — $ 8,416 $ 28,947 Accumulated Amortization Year Ended December 31, 2014 $ (5,429 ) $ (24,179 ) $ (96 ) $ (1,457 ) $ (31,161 ) Amortization expense (624 ) (2,543 ) (192 ) 259 (3,100 ) Fully amortized intangible assets 4,737 22,700 — — 27,437 Year Ended December 31, 2015 (1,316 ) (4,022 ) (288 ) (1,198 ) (6,824 ) Amortization expense (332 ) (1,687 ) (144 ) (314 ) (2,477 ) Fully amortized intangible assets — — 432 — 432 Year Ended December 31, 2016 $ (1,648 ) $ (5,709 ) $ — $ (1,512 ) $ (8,869 ) Weighted average remaining contractual life, in years 5.0 9.2 0.0 8.4 8.6 Future amortization expense of intangible assets for each of the years ended December 31 is as follows (in thousands): 2017 $ 2,346 2018 2,173 2019 2,227 2020 2,227 2021 2,227 Years subsequent to 2021 8,878 $ 20,078 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. 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. If the carrying values of the assets are not recoverable, as determined by the estimated undiscounted cash flows, the estimated fair value of the assets or asset groups are compared to their current carrying values and impairment charges are recorded if the carrying value exceeds fair value. The Company performs its testing on an asset or asset group basis. Generally, fair value is determined using valuation techniques, such as expected discounted cash flows or appraisals, as appropriate. During the years ended December 31, 2016 , 2015 , and 2014 , the Company recognized impairment charges of $130.8 million , $7.1 million and $4.4 million , respectively, r

Business Acquisitions (Notes)

Business Acquisitions (Notes)	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Business Acquisitions	2. BUSINESS ACQUISITIONS Witt O'Brien's. On July 11, 2014, the Company acquired a controlling interest in Witt O’Brien’s through the acquisition of its partner’s 45.8% equity interest for $35.4 million in cash (see Note 4). The Company performed a fair value analysis and the purchase price was allocated to the acquired assets and liabilities based on their fair values resulting in $48.1 million of goodwill being recorded. CCM. On October 31, 2016, the Company acquired certain assets from Central Contracting & Marine, Inc. (“CCM”) consisting primarily of terminal and fleeting assets, including five harbor boats, for $18.1 million in cash. The Company performed a preliminary fair value analysis and the purchase price was allocated to the acquired assets based on their fair values resulting in no goodwill being recorded. SeaJon II. On December 2, 2016, the Company acquired a controlling interest in SeaJon II LLC (“SeaJon II”), which owns one U.S.-flag offshore tug, through the acquisition of its partner’s 50% equity interest for $3.4 million in cash (see Note 4). The Company performed a preliminary fair value analysis and the purchase price was allocated to the acquired assets and liabilities based on their fair values resulting in no goodwill being recorded. Cypress CKOR. On December 12, 2016, the Company obtained a 100% controlling interest in Cypress CKOR LLC (“Cypress CKOR”), an owner of one offshore support vessel, for one dollar and the assumption of $3.1 million in debt. The Company performed a preliminary fair value analysis and the purchase price was allocated to the acquired assets and liabilities based on their fair values resulting in no goodwill being recorded. Purchase Price Allocation. The allocation of the purchase price for the Company’s acquisitions for the years ended December 31 was as follows (in thousands): 2016 2015 2014 Restricted cash $ 275 $ — $ — Trade and other receivables 2,187 — 31,079 Other current assets 150 — 1,925 Investments, at Equity, and Advances to 50% or Less Owned Companies (3,437 ) — (49,968 ) Property and Equipment 17,132 — 519 Goodwill — 3,157 44,967 Intangible Assets 7,098 (3,157 ) 24,901 Other Assets — — 111 Accounts payable 238 — (1,709 ) Other current liabilities (13 ) — (12,274 ) Long-Term Debt (3,091 ) — (3,266 ) Deferred Income Taxes — — 91 Other Liabilities — — (1,376 ) Purchase price (1) $ 20,539 $ — $ 35,000 ______________________ (1) Purchase price is net of cash acquired totaling $0.9 million and $0.4 million in 2016 and 2014 , respectively.

Investments, At Equity, And Adv

Investments, At Equity, And Advances To 50% Or Less Owned Companies	12 Months Ended
	Dec. 31, 2016
Equity Method Investment, Summarized Financial Information [Abstract]
Investments, At Equity, And Advances To 50% Or Less Owned Companies	4. INVESTMENTS, AT EQUITY, AND ADVANCES TO 50% OR LESS OWNED COMPANIES Investments, at equity, and advances to 50% or less owned companies as of December 31 were as follows (in thousands): Ownership 2016 2015 Offshore Marine Services: MexMar 49.0% $ 63,404 $ 50,163 Falcon Global 50.0% 18,539 17,951 Dynamic Offshore 19.0% 15,871 14,172 Sea-Cat Crewzer II 50.0% 11,246 11,339 OSV Partners 30.4% 9,245 11,374 Nautical Power 50.0% 6,413 6,412 Sea-Cat Crewzer 50.0% 4,088 2,701 Other 20.0% – 50.0% 9,505 15,898 138,311 130,010 Inland River Services: SCFCo 50.0% 46,028 57,437 Bunge-SCF Grain 50.0% 16,176 16,695 SCF Bunge Marine 50.0% 4,233 4,544 Other 50.0% 2,744 2,687 69,181 81,363 Shipping Services: Trailer Bridge (1) 55.3% 43,050 41,710 SEA-Access 50.0% — 8,414 SeaJon 50.0% 8,570 7,987 SeaJon II 50.0% — 6,388 51,620 64,499 Other: Hawker Pacific 34.2% 20,418 20,964 VA&E 41.3% 11,133 13,954 Avion 39.1% 14,783 11,994 Cleancor 50.0% 5,373 5,613 Other 34.0% – 50.0 % 2,953 2,706 54,660 55,231 $ 313,772 $ 331,103 ______________________ (1) The Company’s ownership percentage represents its economic interest in the joint venture. Combined Condensed Financial Information. Summarized financial information for the Company’s investments, at equity, excluding Dorian, as of and for the years ended December 31 was as follows (in thousands): 2016 2015 Current assets $ 745,872 $ 603,446 Noncurrent assets 1,009,317 1,066,610 Current liabilities 622,530 401,987 Noncurrent liabilities 458,922 674,896 2016 2015 2014 Operating Revenues $ 1,359,370 $ 1,281,708 $ 1,175,872 Costs and Expenses: Operating and administrative 1,204,496 1,085,518 1,021,730 Depreciation 80,784 94,105 61,233 1,285,280 1,179,623 1,082,963 Gains (Losses) on Asset Dispositions and Impairments, Net (27,900 ) (2,174 ) 368 Operating Income $ 46,190 $ 99,911 $ 93,277 Net Income (Loss) $ (34,569 ) $ 18,835 $ 29,296 As of December 31, 2016 and 2015 , cumulative undistributed net earnings of 50% or less owned companies accounted for by the equity method and included in the Company’s consolidated retained earnings were $7.8 million and $19.9 million , respectively. Condensed Financial Information of Dorian. On December 21, 2015, the Company classified its investment in Dorian as marketable securities. Dorian files periodic reports on Form 10-Q and Form 10-K with the Securities and Exchange Commission (“SEC”). Summarized financial information for Dorian as of and for the years ended December 31 was as follows (in thousands): 2015 (1) 2014 Current assets $ 98,254 $ 198,058 Noncurrent assets 1,724,758 812,164 Current liabilities 88,021 20,662 Noncurrent liabilities 759,636 125,716 2015 (1) 2014 Operating Revenues $ 239,206 $ 78,666 Operating Income 126,820 20,494 Net Income 118,356 15,122 ______________________ (1) Financial information provided is as of and for the year ended December 31, 2015 as it was not practical to obtain financial information through period ended December 21, 2015 without undue difficulty or cost. MexMar. Mantenimiento Express Maritimo, S.A.P.I. de C.V. (“MexMar”) owns and operates 15 offshore support vessels in Mexico. During the year ended December 31, 2016 , the Company contributed additional capital of $7.4 million in cash and sold two offshore support vessels for $34.0 million in cash to MexMar. During the year ended December 31, 2015 , the Company contributed capital of $7.9 million in cash to MexMar. In addition, during the year ended December 31, 2015 , MexMar repaid $15.0 million of seller financing provided by the Company. During the year ended December 31, 2014 , the Company contributed capital of $2.9 million and sold two offshore support vessels for $32.0 million ( $6.4 million in cash and $25.6 million in seller financing, of which $10.7 million was repaid in 2014) to MexMar. During the years ended December 31, 2016 , 2015 and 2014 , the Company received $0.3 million , $0.4 million and $0.3 million , respectively, of vessel management fees from MexMar. During the years ended December 31, 2016 , 2015 and 2014 , MexMar paid the Company $5.1 million , $11.6 million and $13.5 million , respectively, to charter certain vessels under bareboat and time charter arrangements. Falcon Global. On August 1, 2014, the Company and Montco Global, LLC formed Falcon Global LLC (“Falcon Global”) to construct and operate two foreign-flag liftboats. The Company has a 50% ownership interest in Falcon Global. During the years ended December 31, 2016 , 2015 and 2014 , the Company and its partner each contributed capital of $7.7 million , $15.7 million and $3.4 million , respectively, in cash to Falcon Global. During the year ended December 31, 2016 , the Company recorded an impairment charge of $6.4 million , net of tax, for an other-than-temporary decline in the fair value of its investment in Falcon Global (see Note 10). As of December 31, 2016 , the Company has guaranteed $3.8 million related to the construction contract for the liftboats, which declines as progress payments are made in accordance with the contract. In addition, as of December 31, 2016 , the Company has jointly and severally guaranteed $51.8 million of debt used to construct the liftboats. As of December 31, 2016 , the Company’s carrying value of its investment in Falcon Global was $6.4 million lower than its proportionate share of the underlying equity in Falcon Global. Dynamic Offshore Drilling. Dynamic Offshore Drilling Ltd. (“Dynamic Offshore”) was established to construct and operate a jack-up drilling rig that was delivered in the first quarter of 2013. Sea-Cat Crewzer II. Sea-Cat Crewzer II LLC (“Sea-Cat Crewzer II”) owns and operates two high speed offshore catamarans. The Company is a guarantor of its proportionate share of Sea-Cat Crewzer’s II debt and the amount of the guarantee declines as principal payments are made and will terminate when the debt is repaid. As of December 31, 2016 , the Company’s guarantee was $11.6 million . During the year ended December 31, 2015 , the Company received dividends of $1.8 million from Sea-Cat Crewzer II. During the year ended December 31, 2014 , the Company received capital distributions of $14.0 million . During the years ended December 31, 2016 , 2015 and 2014 , the Company received $0.7 million , $0.7 million and $0.7 million , respectively, of vessel management fees from Sea-Cat Crewzer II. OSV Partners. SEACOR OSV Partners GP LLC and SEACOR OSV Partners I LP (collectively “OSV Partners”) owns and operates five offshore support vessels. During the years ended December 31, 2016 , 2015 and 2014 , the Company contributed capital of $1.2 million , $1.4 million and $5.1 million , respectively, in cash to OSV Partners. In addition, during the year ended December 31, 2016 , equity in earnings (losses) of 50% or less owned companies, net of tax, includes $1.0 million related to the Company’s proportionate share of impairment charges associated with OSV Partners’ fleet. During the year ended December 31, 2014 , the Company sold two offshore support vessels for $27.7 million to OSV Partners. During the years ended December 31, 2016 , 2015 and 2014 , the Company received $0.5 million , $1.2 million and $1.2 million , respectively, of vessel management fees from OSV Partners. Nautical Power. The Company and another offshore operator formed Nautical Power, LLC (“Nautical Power”) to operate one offshore support vessel. Nautical Power bareboat chartered the vessel from a leasing company and that charter terminated in 2013. As of December 31, 2016 , the Company’s investment in Nautical Power consists of its share of funds dedicated for future investment. Sea-Cat Crewzer. Sea-Cat Crewzer LLC (“Sea-Cat Crewzer”) owns and operates two high speed offshore catamarans. The Company is a guarantor of its proportionate share of Sea-Cat Crewzer’s debt and the amount of the guarantee declines as principal payments are made and will terminate when the debt is repaid. As of December 31, 2016 , the Company’s guarantee was $10.3 million . During the years ended December 31, 2015 and 2014 , the Company received dividends of $1.3 million and $3.3 million , respectively, from Sea-Cat Crewzer. In addition, during the year ended December 31, 2014 , the Company received capital distributions of $3.2 million from Sea-Cat Crewzer. During the years ended December 31, 2016 , 2015 and 2014 , the Company received $0.7 million , $0.7 million and $0.7 million , respectively, of vessel management fees from Sea-Cat Crewzer. During the years ended December 31, 2016 , 2015 and 2014 , the Company paid $4.3 million , $5.9 million and $6.7 million , respectively, to Sea-Cat Crewzer to bareboat charter one of its vessels. Other Offshore Marine Services. The Company’s other Offshore Marine Services 50% or less owned companies own and operate ten vessels. During the year ended December 31, 2016 , the Company received dividends of $0.8 million from these 50% or less owned companies and made capital contributions of $0.5 million to these 50% or less owned companies. In addition, during the year ended December 31, 2016 , the Company recognized impairment charges of $0.5 million , net of tax, for an other-than-temporary decline in the fair value of its investment in a certain 50% or less owned company and recognized $2.7 million , net of tax, for its proportionate share of impairment charges recognized by certain of its 50% or less owned companies related to offshore support vessels used in their operations, both of which are included in equity in earnings (losses) of 50% or less owned companies, net of tax in the accompanying consolidated statements of income (loss). During the year ended December 31, 2015 , the Company received dividends of $0.9 million and repayments on advances of $0.2 million from these 50% or less owned companies. In addition, during the year ended December 31, 2015 , the Company recognized impairment charges of $2.0 million , net of tax, for its proportionate share of impairment charges recognized by certain of its 50% or less owned companies related to offshore support vessels used in their operations, which are included in equity in earnings (losses) of 50% or less owned companies in the accompanying consolidated statements of income (loss). During the year ended December 31, 2014 , the Company received capital distributions of $0.2 million , dividends of $1.0 million and repayments of advances of $0.6 million , and made capital contributions and advances of $0.8 million to these 50% or less owned companies. Certain of these 50% or less owned companies obtained bank debt to finance the acquisition of offshore support vessels from the Company. Under the terms of the debt, the bank has the authority, under certain circumstances, to require the parties of these 50% or less owned companies to fund uncalled capital commitments, as defined in the 50% or less owned companies’ partnership agreements. In such an event, the Company would be required to contribute its allocable share of the uncalled capital commitments, which was $1.8 million in the aggregate as of December 31, 2016 . The Company manages certain vessels on behalf of its 50% or less owned companies and guarantees the outstanding charter receivables of one of its 50% or less owned companies if a customer defaults in payment and the Company either fails to take enforcement action against the defaulting customer or fails to assign its right of recovery against the defaulting customer. As of December 31, 2016 , the Company’s contingent guarantee of outstanding charter receivables was $0.4 million . During the years ended December 31, 2016 , 2015 and 2014 , the Company received $0.8 million , $0.8 million and $0.6 million , respectively, of vessel management fees from these 50% or less owned companies. SCFCo. SCFCo Holdings LLC (“SCFCo”) was established to operate dry-cargo barges and towboats on the Parana-Paraguay Rivers and a terminal facility at Port Ibicuy, Argentina. During the years ended December 31, 2016 , 2015 and 2014 , the Company contributed capital of $0.8 million , $18.0 million and $19.7 million , respectively, to SCFCo. During the years ended December 31, 2016 and 2014 , the Company provided working capital advances and loans of $1.8 million and $23.5 million , respectively. In addition, during the year ended December 31, 2014 , the Company financed the sale of one inland river towboat and 20 dry-cargo barges to SCFCo for $13.0 million . During the years ended December 31, 2015 and 2014 , the Company received repayments on these working capital advances, loans and financings of $14.0 million and $1.0 million , respectively. As of December 31, 2016 , $30.3 million of working capital advances and loans remained outstanding. The Company also provides SCFCo with certain information technology services and received $0.1 million and $0.2 million , respectively, for these services during the years ended December 31, 2016 and 2015 . During the years ended December 31, 2016 and 2015, the Company identified indicators of impairment in its investment in SCFCo as a result of continuing losses and recognized impairment charges of $7.7 million and $21.5 million , respectively, for an other-than-temporary decline in the fair value of its investment (see Note 10). As of December 31, 2016 , the Company’s carrying value of its investment in SCFCo was $28.5 million lower than its proportionate share of the underlying equity in SCFCo. Bunge-SCF Grain. Bunge-SCF Grain LLC (“Bunge-SCF Grain”) operates a terminal grain elevator in Fairmont City, Illinois. During the year ended December 31, 2014 , the Company contributed capital of $2.0 million in cash and made working capital advances of $2.0 million to Bunge-SCF Grain. During the year ended December 31, 2015 , the Company received $2.0 million of repayments of working capital advances. As of December 31, 2016 , the total outstanding balance of working capital advances was $7.0 million . In addition, Bunge-SCF Grain operates and manages the Company’s grain storage and handling facility in McLeansboro, Illinois, and the Company received $1.0 million , $1.0 million and $1.0 million in rental income for the years ended December 31, 2016 , 2015 and 2014 , respectively. The Company also provides freight transportation to Bunge-SCF Grain and received $7.2 million , $10.8 million and $7.8 million for these services during the years ended December 31, 2016 , 2015 and 2014 , respectively. SCF Bunge Marine. SCF Bunge Marine LLC (“SCF Bunge Marine”) provides towing services on the U.S. Inland River Waterways, primarily the Mississippi River, Illinois River, Tennessee River and Ohio River. The Company time charters six inland river towboats to SCF Bunge Marine, of which four are bareboat chartered-in by the Company from a third-party leasing company. The Company and its partner are required to fund SCF Bunge Marine, if necessary, to support the payment of its time charter obligations to the Company. Pursuant to the time charter, the Company received charter fees of $35.0 million , $41.7 million and $41.6 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. During the years ended December 31, 2016 , 2015 and 2014 , the Company received dividends of $2.5 million , $4.0 million and $4.5 million , respectively, from SCF Bunge Marine. In addition, during the years ended December 31, 2016 , 2015 and 2014 , SCF Bunge Marine received $40.2 million , $47.9 million and $46.6 million , respectively, for towing services provided to the Company. Other Inland River Services. The Company’s other Inland River Services 50% or less owned company operates a fabrication facility. During the year ended December 31, 2014 , the Company received capital distributions of $2.1 million from this 50% or less owned company. Dorian. During the year ended December 31, 2014, Dorian completed three private placement equity offerings prior to becoming a publicly traded company in May of 2014. The Company did not participate in any of the offerings and as a consequence its ownership was diluted to a 16.1% ownership interest and the Company recognized a $4.4 million gain, net of tax, which is included in equity in earnings (losses) of 50% or less owned companies in the accompanying consolidated statements of income (loss). During the year ended December 31, 2015 , the Company sold 150,000 shares of Dorian for $2.3 million in cash reducing the Company’s ownership to 15.9% . On December 21, 2015, Mr. Fabrikant, the Executive Chairman and Chief Executive Officer of SEACOR, resigned from Dorian’s board of directors. As a consequence, the Company determined it no longer exercised significant influence over Dorian and marked its investment, at equity, in Dorian to fair value resulting in a loss of $32.3 million , net of tax, which is included in equity in earnings (losses) of 50% or less owned companies in the accompanying consolidated statements of income (loss). The Company’s investment in Dorian is classified as marketable securities in the accompanying consolidated balance sheet (see Note 1). Trailer Bridge. Trailer Bridge, Inc. (“Trailer Bridge”), an operator of U.S.-flag deck and RORO barges, provides marine transportation services between Jacksonville, Florida, San Juan, Puerto Rico and Puerto Plata, Dominican Republic. In December 2016, the Company and other major investors recapitalized Trailer Bridge by agreeing to exchange outstanding subordinated debt for equity. As a consequence of the recapitalization, the Company’s noncontrolling interest in Trailer Bridge increased to 55.3% resulting in an equity loss of $2.2 million , net of tax. The Company provides secured financing to Trailer Bridge and during the year ended December 31, 2016 , the Company provided advances of $1.7 million on the secured financing. During the years ended December 31, 2015 and 2014 , the Company received repayments of $18.7 million and $2.1 million , respectively, on the secured financing. As of December 31, 2016 , the outstanding amount on the secured financing was $3.9 million , inclusive of accrued and unpaid interest. During the years ended December 31, 2016 , 2015 and 2014 , the Company received $3.0 million , $0.4 million and $2.0 million , respectively, for the time charter of a U.S.-flag harbor tug to Trailer Bridge. The Company also provides Trailer Bridge with technical and commercial management services and during the years ended December 31, 2016 and 2015 , received $0.3 million and $0.8 million , respectively, for these services. SEA-Access. On November 7, 2014, the Company and Access Shipping Limited Partnership formed SEA-Access LLC (“SEA-Access”) to acquire and operate the M/V Eagle Ford , a U.S.-flag 124,000 dwt crude oil tanker. In June 2016, the M/V Eagle Ford was scrapped and, as of December 31, 2016 , SEA-Access had been liquidated. During the year ended December 31, 2014 , the Company and its partner each contributed capital of $16.7 million to SEA-Access to acquire the vessel and for working capital. During the year ended December 31, 2016 , the Company received capital distributions of $8.4 million and dividends of $2.0 million from SEA-Access. During the year ended December 31, 2015 , the Company received capital distributions of $8.3 million and dividends of $4.4 million from SEA-Access. The Company also provided SEA-Access with technical and commercial management services and received $0.5 million , $1.0 million and $0.1 million , for the years ended December 31, 2016 , 2015 and 2014 , respectively, for these services. SeaJon. SeaJon LLC (“SeaJon”) owns an articulated tug-barge operating in the Great Lakes trade. The Company is a guarantor of its proportionate share of SeaJon’s debt up to a maximum of $5.0 million . As of December 31, 2016 , the Company’s guarantee was $5.0 million . During the year ended December 31, 2014 , the Company and its partner each made capital contributions of $2.3 million . In addition, during the year ended December 31, 2014 , SeaJon made a $5.4 million non-cash distribution of an interest in an offshore tug under reconstruction to each partner (see SeaJon II). During the years ended December 31, 2016 and 2015 , the Company received dividends of $0.6 million and $0.6 million , respectively, from SeaJon. SeaJon II. On October 1, 2014, the Company and Donjon Marine Co., Inc. formed SeaJon II LLC (“SeaJon II”) to own a U.S.-flag offshore tug on time charter to Trailer Bridge. During the years ended December 31, 2015 and 2014 , the Company and its partner each contributed capital of $1.0 million and $0.6 million , respectively, in cash. During the year ended December 31, 2014 , the Company and its partner each contributed an interest in an offshore tug under construction valued at $5.4 million (see SeaJon). During the year ended December 31, 2015 , the Company received capital distributions of $0.3 million from SeaJon II. The Company also provides SeaJon II with technical and commercial management services and received $0.1 million and $0.1 million , during the years ended December 31, 2016 and 2015 , respectively, for these services. On December 2, 2016, the Company acquired a controlling interest in SeaJon II through the acquisition of its partner’s 50% equity interest for $3.4 million in cash (see Note 2). Upon the change in control, the Company marked its investment in SeaJon II to fair value resulting in a loss of $1.9 million , net of tax, which is included in equity in earnings (losses) of 50% or less owned companies in the accompanying consolidated statements of income (loss) (see Note 10). Hawker Pacific. Hawker Pacific Airservices, Limited (“Hawker Pacific”) is an aviation sales and support organization and a distributor of aviation components from leading manufacturers. As of December 31, 2016 , the Company had a $6.5 million letter of credit outstanding in support of certain Hawker Pacific performance guarantees. During the years ended December 31, 2016 , 2015 and 2014 , the Company received management fees of $0.3 million , $0.3 million and $0.5 million , respectively, from Hawker Pacific. VA&E. On June 1, 2015, the Company contributed its 81.1% interest in the assets and liabilities of a previously controlled and consolidated subsidiary that operated its agricultural commodity trading and logistics business (including $3.5 million of cash on hand) in exchange for a 41.3% ownership interest in each of VA&E Trading USA LLC and VA&E Trading LLP (collectively “VA&E”), two newly formed 50% or less owned companies with certain subsidiaries of ECOM Agroindustrial Corp. Ltd. and certain managers of 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. Through November 2016, the Company provided VA&E an unsecured revolving credit facility of up to $6.0 million , a term loan of $1.1 million and a subordinated loan of $1.0 million . In December 2016, the Company increased its subordinated loan to $3.5 million and terminated the revolving credit facility and term loan. During the years ended December 31, 2016 and 2015 , VA&E borrowed $10.0 million and $15.0 million , respectively and repaid $12.4 million and $11.5 million , respectively, on the revolving credit facility. During the year ended December 31, 2016 , the Company received repayments of $1.1 million on its term loan. During the year ended December 31, 2015 , the Company and its partner each funded $1.0 million under the subordinated note executed upon formation of VA&E. As of December 31, 2016 , the Company had outstanding advances of $3.6 million to VA&E inclusive of accrued and unpaid interest. Avion. Avion Pacific Limited (“Avion”) is a distributor of aircraft and aircraft related parts. During the years ended December 31, 2016 and 2014 , the Company made advances of $3.0 million and $3.0 million , respectively, to Avion. During the years ended December 31, 2015 and 2014 , the Company received repayments on advances of $3.0 million and $4.0 million , respectively, from Avion. As of December 31, 2016 , the Company had $3.0 million of outstanding advances to Avion. Cleancor. CLEANCOR Energy Solutions LLC (“Cleancor”) a full service solution provider delivering clean fuel to end users. During the year ended December 31, 2014 , the Company contributed capital of $4.8 million to Cleancor to fund its start-up operations and provide capital for future investments. During the year ended December 31, 2015 , the Company provided Cleancor financing of $2.0 million for certain equipment, of which $1.9 million was outstanding as of December 31, 2016 . Witt O’Brien’s. On December 31, 2012, the Company contributed its interest in O’Brien’s Response Management Inc. (“ORM”) to Witt Group Holdings, LLC, which was renamed Witt O’Brien’s, LLC. On July 11, 2014, the Company acquired a controlling interest in Witt O’Brien’s through the acquisition of its partner’s equity interest (see Note 2). During the six months ended June 30, 2014, the Company received capital distributions of $0.4 million and dividends of $0.4 million from Witt O’Brien’s. During the six months ended December 31, 2014 , the Company received management fees of $0.1 million from Witt O’Brien’s. Other. The Company’s other 50% or less owned companies are primarily industrial aviation businesses in Asia. During the years ended December 31, 2016 , 2015 and 2014 , the Company contributed capital and made advances of $0.8 million , $0.2 million and $1.7 million , respectively, to these 50% or less owned companies. During the year ended December 31, 2014 , the Company received capital distributions of $0.1 million from these 50% or less owned companies.

Construction Reserve Funds Cons

Construction Reserve Funds Construction Reserve Funds (Notes)	12 Months Ended
	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Construction Reserve Funds Disclosure [Text Block]	5. CONSTRUCTION RESERVE FUNDS The Company has established, pursuant to Section 511 of the Merchant Marine Act, 1936, as amended, construction reserve fund accounts subject to agreements with the Maritime Administration. In accordance with this statute, the Company is permitted to deposit proceeds from the sale of certain vessels into the construction reserve fund accounts and defer the taxable gains realized from the sale of those vessels. Qualified withdrawals from the construction reserve fund accounts are only permitted for the purpose of acquiring qualified U.S.-flag vessels as defined in the statute and approved by the Maritime Administration. To the extent that sales proceeds are reinvested in replacement vessels, the carryover depreciable tax basis of the vessels originally sold is attributed to the U.S.-flag vessels acquired using such qualified withdrawals. The construction reserve funds must be committed for expenditure within three years of the date of sale of the equipment, subject to two one-year extensions that can be granted at the discretion of the Maritime Administration, or be released for the Company’s general use as nonqualified withdrawals. For nonqualified withdrawals, the Company is obligated to pay taxes on the previously deferred gains at the prevailing statutory tax rate plus penalties and interest thereon for the period such taxes were deferred. The Company’s construction reserve funds are classified as non-current assets in the accompanying consolidated balance sheets as the Company has the intent and ability to use the funds to acquire equipment. Construction reserve fund transactions for the years ended December 31 were as follows (in thousands): 2016 2015 2014 Withdrawals $ (130,446 ) $ (47,472 ) $ (131,167 ) Deposits 29,000 34,459 147,450 $ (101,446 ) $ (13,013 ) $ 16,283
Schedule of Construction Reserve Funds [Table Text Block]	Construction reserve fund transactions for the years ended December 31 were as follows (in thousands): 2016 2015 2014 Withdrawals $ (130,446 ) $ (47,472 ) $ (131,167 ) Deposits 29,000 34,459 147,450 $ (101,446 ) $ (13,013 ) $ 16,283

Third Party Notes Receivable

Third Party Notes Receivable	12 Months Ended
	Dec. 31, 2016
Notes, Loans and Financing Receivable, Net, Noncurrent [Abstract]
Loans, Notes, Trade and Other Receivables Disclosure [Text Block]	6. LEASES AND NOTES RECEIVABLE FROM THIRD PARTIES From time to time, the Company engages in lending and leasing activities involving various types of equipment. The Company recognizes interest income as payments are due, typically monthly, and expenses all costs associated with its lending and leasing activities as incurred. These leases and notes receivable are typically collateralized by the underlying equipment and require scheduled lease payments or periodic principal and interest payments. As of December 31, 2016 and 2015 , the outstanding balance of leases and notes receivable from third parties was $12.6 million and $24.9 million , respectively, and is included in other long-term assets in the accompanying consolidated balance sheets. During the years ended December 31, 2016 , 2015 and 2014 , the Company made advances on notes receivable from third parties of $9.4 million , $9.6 million and $19.0 million , respectively, and received repayments on notes receivable from third parties of $6.8 million , $10.8 million and $10.0 million , respectively. During the year ended December 31, 2014 , the Company received net lease payments of $0.6 million from third parties. During the year ended December 31, 2016 , the Company recognized reserves of $8.5 million for two notes receivable from third parties following non-performance and a decline in the underlying collateral values (see Note 10).

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2016
Long-term Debt, Unclassified [Abstract]
Long-Term Debt	7. LONG-TERM DEBT The Company’s borrowings as of December 31 were as follows (in thousands): 2016 2015 3.0% Convertible Senior Notes (1) $ 230,000 $ 230,000 2.5% Convertible Senior Notes (2) 157,128 284,500 7.375% Senior Notes (3) 160,699 195,941 3.75% Subsidiary Convertible Senior Notes (4) 175,000 175,000 SEA-Vista Credit Facility (5) 279,245 210,025 Other (6) 82,742 54,287 1,084,814 1,149,753 Portion due within one year, net of related debt discount and issuance costs (183,602 ) (35,531 ) Debt discount included in long-term debt (39,537 ) (62,914 ) Debt issuance costs included in long-term debt (12,904 ) (16,449 ) $ 848,771 $ 1,034,859 ______________________ (1) Excludes unamortized discount and unamortized issue costs of $29.8 million and $3.0 million , respectively, as of December 31, 2016 and $36.2 million and $3.7 million , respectively, as of December 31, 2015 . (2) Excludes unamortized discount and unamortized issue costs of $4.8 million and $0.8 million , respectively, as of December 31, 2016 and $17.3 million and $2.8 million , respectively, as of December 31, 2015 . (3) Excludes unamortized discount and unamortized issue costs of $0.4 million and $0.5 million , respectively, as of December 31, 2016 and $0.6 million and $0.9 million , respectively, as of December 31, 2015 . (4) Excludes unamortized discount and unamortized issue costs of $4.1 million and $3.1 million , respectively, as of December 31, 2016 and $8.2 million and $6.2 million , respectively, as of December 31, 2015 . (5) Excludes unamortized issue costs of $2.0 million and $2.7 million as of December 31, 2016 and December 31, 2015 , respectively. (6) Excludes unamortized discount and unamortized issue costs of $0.5 million and $3.5 million , respectively, as of December 31, 2016 and unamortized discount and unamortized issue costs of $0.6 million and $0.2 million , respectively, as of December 31, 2015 . The Company’s contractual long-term debt maturities for the years ended December 31 are as follows (in thousands): 2017 (1) $ 189,164 2018 21,766 2019 183,212 2020 238,846 2021 25,800 Years subsequent to 2021 426,026 $ 1,084,814 ______________________ (1) Includes the aggregate principal amount outstanding of the Company’s 2.5% Convertible Senior Notes with a contractual maturity date of December 15, 2027 as the holders may require the Company to repurchase the notes on December 19, 2017. 3.0% Convertible Senior Notes. On November 13, 2013, SEACOR issued $230.0 million aggregate principal amount of its 3.0% Convertible Senior Notes due November 15, 2028 (the “ 3.0% Convertible Senior Notes”). Interest on the 3.0% Convertible Senior Notes is payable semi-annually on May 15 and November 15 of each year. Beginning November 15, 2020, contingent interest is payable during any subsequent semi-annual interest period if the average trading price of the 3.0% Convertible Senior Notes for a defined period is greater than or equal to $1,200 per $1,000 principal amount of the 3.0% Convertible Senior Notes. The amount of contingent interest payable for any such period will be equal to 0.45% per annum of such average trading price of the 3.0% Convertible Senior Notes. After March 31, 2014 and prior to August 15, 2028, the 3.0% Convertible Senior Notes are convertible into shares of SEACOR common stock, par value $0.01 per share (“Common Stock”), at the initial conversion rate (“Conversion Rate”) of 7.9362 shares per $1,000 principal amount of notes only if certain conditions are met, as more fully described in the indenture. After August 15, 2028, holders may elect to convert at any time. The Company has reserved the maximum number of shares of Common Stock needed upon conversion, or 1,825,326 shares as of December 31, 2016 . On or after November 19, 2018, the 3.0% Convertible Senior Notes may be redeemed, in whole or in part, at a price equal to 100% of the principal amount, plus accrued and unpaid interest to the date of redemption. On November 19, 2020, November 20, 2023 or if the Company undergoes a fundamental change, as more fully described in the indenture, the holders of the 3.0% Convertible Senior Notes may require SEACOR to purchase for cash all or part of the notes at a price equal to 100% of the principal amount, plus accrued and unpaid interest to the date of purchase. The Company accounts separately for the liability and equity components of the 3.0% Convertible Senior Notes and the associated underwriting fees in a manner that reflects the Company’s non-convertible borrowing rate. The resulting debt discount and offering costs associated with the liability component is amortized as additional non-cash interest expense over the seven year period for which the debt is expected to be outstanding (November 19, 2020) for an overall effective annual interest rate of 7.4% . 2.5% Convertible Senior Notes. On December 11, 2012, SEACOR issued $350.0 million aggregate principal amount of its 2.5% Convertible Senior Notes due December 15, 2027 (the “ 2.5% Convertible Senior Notes”). Interest on the 2.5% Convertible Senior Notes is payable semi-annually on June 15 and December 15 of each year. Beginning December 15, 2017, contingent interest is payable during any subsequent semi-annual interest period if the average trading price of the 2.5% Convertible Senior Notes for a defined period is greater than or equal to $1,200 per $1,000 principal amount of the 2.5% Convertible Senior Notes. The amount of contingent interest payable for any such period will be equal to 0.25% per annum of such average trading price of the 2.5% Convertible Senior Notes. Prior to September 15, 2017, the 2.5% Convertible Senior Notes are convertible into shares of Common Stock at a conversion rate of 12.0015 shares per $1,000 principal amount of notes only if certain conditions are met, as more fully described in the indenture. After September 15, 2017, holders may elect to convert at any time. The Company has reserved the maximum number of shares of Common Stock needed upon conversion, or 1,885,772 shares as of December 31, 2016 . After December 19, 2015 and prior to December 19, 2017, the 2.5% Convertible Senior Notes may be redeemed, in whole or in part, only if certain conditions are met, as more fully described in the indenture, at a price equal to 100% of the principal amount, plus accrued and unpaid interest to the date of redemption, plus $55 per $1,000 principal amount of notes. On or after December 19, 2017, the 2.5% Convertible Senior Notes may be redeemed, in whole or in part, at a price equal to 100% of the principal amount, plus accrued and unpaid interest to the date of redemption. On December 19, 2017, December 19, 2022 or if the Company undergoes a fundamental change, as more fully described in the indenture, the holders of the 2.5% Convertible Senior Notes may require SEACOR to purchase for cash all or part of the notes at a price equal to 100% of the principal amount, plus accrued and unpaid interest to the date of purchase. The Company accounts separately for the liability and equity components of the 2.5% Convertible Senior Notes and the associated underwriting fees in a manner that reflects the Company’s non-convertible borrowing rate. The resulting debt discount and offering costs associated with the liability component is amortized as additional non-cash interest expense over the five year period for which the debt is expected to be outstanding (December 19, 2017) for an overall effective annual interest rate of 6.5% . During the year ended December 31, 2016 , the Company repurchased $127.4 million in principal amount of its 2.5% Convertible Senior Notes for total consideration of $124.7 million . Consideration of $117.3 million was allocated to the settlement of the long-term debt resulting in gains on debt extinguishment of $3.3 million included in the accompanying consolidated statements of income (loss). Consideration of $7.4 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. During the year ended December 31, 2015 , the Company repurchased $65.5 million in principal amount of its 2.5% Convertible Senior Notes for total consideration of $62.6 million . Consideration of $59.6 million was allocated to the settlement of the long-term debt resulting in gains on debt extinguishment of $1.1 million included in the accompanying consolidated statements of income (loss). Consideration of $3.0 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. On September 24, 2009, SEACOR issued $250.0 million aggregate principal amount of its 7.375% Senior Notes due October 1, 2019 (the “ 7.375% Senior Notes”). The 7.375% Senior Notes were issued under a supplemental indenture dated as of September 24, 2009 (the “2009 Supplemental Indenture”) to the base indenture relating to SEACOR’s senior debt securities, dated as of January 10, 2001, between SEACOR and U.S. Bank National Association, as trustee. Interest on the 7.375% Senior Notes is payable semi-annually on April 1 and October 1 of each year. The 7.375% Senior Notes may be redeemed at any time, in whole or in part, at a price equal to the principal amount, plus accrued and unpaid interest to the date of redemption, plus a specified “make-whole” premium. The 2009 Supplemental Indenture contained covenants including, among others, limitations on liens and sale and leasebacks of certain Principal Properties, as defined, and certain restrictions on SEACOR consolidating with or merging into any other Person, as more fully described in the indenture. During the year ended December 31, 2016 , the Company repurchased $35.2 million in principal amount of its 7.375% Senior Notes for $33.1 million resulting in gains on debt extinguishment of $1.9 million included in the accompanying consolidated statements of income (loss). During the year ended December 31, 2015 , the Company repurchased $37.6 million in principal amount of its 7.375% Senior Notes for $37.9 million resulting in losses on debt extinguishment of $0.6 million included in the accompanying consolidated statements of income (loss). 3.75% Subsidiary Convertible Senior Notes. On December 1, 2015, SEACOR Marine Holdings Inc. (“SMHI”), a subsidiary of SEACOR that is the parent company of the Offshore Marine Services business segment, issued $175.0 million aggregate principal amount of its 3.75% Convertible Senior Notes due December 1, 2022 (the “ 3.75% Subsidiary Convertible Senior Notes”) to investment funds managed and controlled by The Carlyle Group. Interest on the 3.75% Subsidiary Convertible Senior Notes is payable semi-annually on June 15 and December 15 of each year, commencing June 15, 2016. On November 30, 2015, SEACOR and the holders of the 3.75% Subsidiary Convertible Senior Notes also entered into an exchange agreement whereby the holders may elect to exchange the principal amount of their outstanding notes, in whole or in part, into shares of Common Stock at an initial exchange rate of 12.82 shares of Common Stock per $1,000 principal amount of the notes (the “Exchange Option”) beginning upon the earlier of December 1, 2017 or the date on which the Offshore Marine Services business segment’s assets reach a specified percentage of the Company’s consolidated assets. The Company, at its option, may under certain circumstances settle any of the 3.75% Subsidiary Convertible Senior Notes submitted for exchange into Common Stock through the issuance of an equal number of warrants in order to facilitate the Company’s compliance with the provisions of the Jones Act. The warrants, if issued, would entitle its holders to purchase an equal number of shares of Common Stock at an exercise price of $0.01 per share upon the resolution of any Jones Act compliance issues. The Company has reserved the maximum number of shares of Common Stock issuable upon exchange of the notes and potential exercise of warrants, or 2,243,500 shares as of December 31, 2016 . On January 11, 2018, the holders of the 3.75% Subsidiary Convertible Senior Notes may require SMHI to purchase for cash all or part of the notes at a price equal to 100% of the principal amount, plus accrued and unpaid interest to the date of purchase (the “2018 Put Option”). Upon consummation of a fundamental change in SMHI or SEACOR, as more fully described in the note purchase agreement, the Company may redeem all the 3.75% Subsidiary Convertible Senior Notes for cash at a price equal to the greater of 100% of the principal amount, plus accrued and unpaid interest to the date of redemption, or the fair value of consideration the holders of the 3.75% Subsidiary Convertible Senior Notes would have received if exchanged into Common Stock or converted into SMHI immediately prior to the fundamental change (the “Fundamental Change Call”). The Company has determined that the Exchange Option is an embedded derivative within the 3.75% Subsidiary Convertible Senior Notes required to be valued separate and apart from the 3.75% Subsidiary Convertible Senior Notes and recorded at fair value (see Notes 9 and 10). On December 1, 2015, the fair value of the bifurcated embedded derivative was $8.5 million and recorded as an exchange option liability on subsidiary convertible senior notes in the accompanying consolidated balance sheets resulting in a corresponding debt discount in an equal amount. The debt discount and $6.4 million in offering costs are being amortized as additional non-cash interest expense over the period for which the debt is expected to be outstanding (January 11, 2018) for an overall effective interest rate of 8.7% . The issuance of the 3.75% Subsidiary Convertible Senior Notes contemplates the potential separation of SMHI from the Company via a spin-off of SMHI to SEACOR’s shareholders (the “SMHI Spin-off”). The Company is continuing to pursue a SMHI Spin-off but is under no obligation to do so; however, if the contemplated SMHI Spin-off were to occur, the Exchange Option, the 2018 Put Option and the Fundamental Change Call would immediately terminate and the holders would then be able to elect to convert the principal amount of their outstanding notes, in whole or in part, into shares of SMHI common stock at an initial conversion rate of 23.26 shares of SMHI common stock per $1,000 principal amount of the notes through November 29, 2022. SMHI, at its option, may under certain circumstances settle any of the 3.75% Subsidiary Convertible Senior Notes submitted for conversion into SMHI common stock through the issuance of an equal number of warrants in order to facilitate SMHI’s compliance with the provisions of the Jones Act. The warrants, if issued, would entitle its holders to purchase an equal number of shares of SMHI common stock at an exercise price of $0.01 per share upon the resolution of any Jones Act compliance issues. SMHI has reserved the maximum number of shares of its common stock needed upon conversion of the notes and potential exercise of warrants, or 4,070,500 shares as of December 31, 2016 . The holders of the 3.75% Subsidiary Convertible Senior Notes have no right to convert into SMHI common stock prior to the completion of a SMHI Spin-off. Following a SMHI Spin-off, if SMHI undergoes a fundamental change, as more fully described in the note purchase agreement, the holders of the 3.75% Subsidiary Convertible Senior Notes may require SMHI to purchase for cash all or part of the notes at a price equal to 100% of the principal amount, plus accrued and unpaid interest to the date of purchase. Following a SMHI Spin-off, the 3.75% Subsidiary Convertible Senior Notes may be redeemed, in whole or in part, only if certain conditions are met, as more fully described in the note purchase agreement, at a price equal to 100% of the principal amount, plus accrued and unpaid interest to the date of redemption. SEA-Vista Credit Facility. On April 15, 2015, SEA-Vista entered into a $300.0 million credit agreement with a syndicate of lenders that matures in 2020 (the “SEA-Vista Credit Facility”) and is secured by substantially all of SEA-Vista’s tangible and intangible assets with no recourse to SEACOR or its other subsidiaries. The SEA-Vista Credit Facility is comprised of three tranches: (i) a $100.0 million revolving credit facility (the “Revolving Loan”); (ii) an $80.0 million term loan (the “Term A-1 Loan”); and (iii) a $120.0 million delayed draw term loan (the “Term A-2 Loan”). The proceeds from the SEA-Vista Credit Facility were and will be used to fund SEA-Vista’s working capital, general corporate purposes, capital commitments and the redemption of its Title XI Bonds (see note below). All three loans bear interest at a variable rate determined by reference to the London Interbank Offered Rate (“LIBOR”) plus a margin of between 2.00% and 2.75% as determined in accordance with the SEA-Vista Credit Facility or, at the election of SEA-Vista, a Base Rate plus a margin of between 1.25% and 1.75% as determined in accordance with the SEA-Vista Credit Facility. A quarterly fee is payable on the unused commitments of all three tranches. SEA-Vista incurred $3.1 million of issuance costs related to the SEA-Vista Credit Facility. Each of the loans under the SEA-Vista Credit Facility will mature on April 15, 2020 (the “Maturity Date”), which may be accelerated in certain circumstances. The principal of the Term A-1 Loan is repayable commencing in June 2015 in quarterly installments of 1.25% of the aggregate principal amount of the Term A-1 Loan through June 30, 2017. Commencing on September 30, 2017, the principal of each of the Term A-1 Loan and the Term A-2 Loan is repayable in quarterly installments of 2.50% of the aggregate principal amount of such loans, with the outstanding principal balance, interest and all other amounts outstanding for all loans, including the Revolving Loan, due and payable on the Maturity Date. Commencing with the calendar year ending December 31, 2016, SEA-Vista is required to make annual prepayments on the Term A-1 Loan and the Term A-2 Loan in an amount equal to 50% of annual excess cash flow (as defined), with prepayments continuing on an annual basis until an amount equal to $75.0 million of the aggregate principal amount of the term loans has been repaid. Each such payment is to be made on or before May 15 of the subsequent calendar year (i.e., commencing May 15, 2017). In addition, SEA-Vista has the right to make optional prepayments on each of the loans without penalty in minimum amounts of $1.0 million . During the year ended December 31, 2016 , SEA-Vista drew $87.0 million and repaid $14.0 million on the Revolving Loan and made scheduled repayments of $3.8 million on the Term A-1 Loan. As of December 31, 2016 , SEA-Vista had $14.0 million of borrowing capacity under the SEA-Vista Credit Facility. Subsequent to December 31, 2016 , SEA-Vista borrowed $14.0 million on the Revolving Loan. During the year ended December 31, 2015 , SEA-Vista drew $30.0 million and repaid $17.0 million on the Revolving Loan, borrowed $80.0 million and made scheduled repayments of $3.0 million on the Term A-1 Loan and borrowed $120.0 million under the Term A-2 Loan. The SEA-Vista Credit Facility contains various financial maintenance and restrictive covenants including: funded debt to adjusted EBITDA; adjusted EBITDA to interest expense plus amortization; aggregate collateral vessel value to the sum of funded debt and unused and unexpired commitments; and minimum liquidity. In addition, the SEA-Vista Credit Facility restricts the payment of dividends and distributions as defined in the SEA-Vista Credit Facility. Title XI Bonds. Three double-hull product and chemical tankers (the “Title XI tankers”) owned by subsidiaries of the Company (the “Title XI companies”) were financed through the issuance of U.S. Government Guaranteed Ship Financing Bonds (the “Title XI Bonds”). On June 1, 2015, SEA-Vista redeemed its Title XI bonds for $99.9 million and recorded a $29.0 million loss on extinguishment of debt for the then unamortized debt discount, the make whole premium paid and certain other redemption costs. As a consequence of redeeming the bonds prior to their scheduled maturity, SEA-Vista was required to pay a make whole premium in the amount of $20.5 million . The redemption of the bonds released the liens on vessels supporting the Title XI financing and facilitated the issuance of the SEA-Vista Credit Facility. The redemption of the Title XI bonds was funded with advances from the SEA-Vista Credit Facility, its restricted cash and $9.6 million of Title XI reserve funds. During the year ended December 31, 2014, the Company made $5.9 million of scheduled payments. ICP Revolving Credit Facility. On April 9, 2015, ICP entered into a $30.0 million revolving credit facility with JP Morgan Chase Bank, N.A. serving as Administrative Agent and Lender (the “ICP Revolving Credit Facility”), which includes an accordion feature whereby loan commitments available under the facility could be increased in the future by an additional $20.0 million , subject to lender approval. The ICP Revolving Credit Facility will primarily be used to finance working capital requirements and for general corporate purposes. The ICP Revolving Credit Facility matures on April 9, 2018 and is secured by all assets of ICP, except real estate, with no recourse to SEACOR or its other subsidiaries. ICP has agreed not to pledge its real estate as collateral to any other party. The amount available for borrowing at any given time under the ICP Revolving Credit Facility is determined by a formula based on the current outstanding loan balance, the amount of ICP’s eligible outstanding accounts receivable balances, and the carrying value of its eligible inventories, subject to additional reserves. Interest on outstanding loans would equate to the one-month LIBOR interest rate plus an applicable margin of 2.00% . A monthly commitment fee is payable based on the unused amounts of the ICP Revolving Credit Facility. The ICP Revolving Credit Facility places restrictions on ICP including limitations on its ability to incur indebtedness, liens, restricted payments, and asset sales. Other restricted payments, including dividends, are subject to certain conditions, including undrawn availability under the ICP Revolving Credit Facility and ICP’s pro forma fixed charge coverage ratio, as defined. In addition, ICP is subject to various covenants under this agreement, as defined. ICP incurred $0.3 million in issuance costs related to the ICP Revolving Credit Facility. As of December 31, 2016 , ICP had no borrowings on the ICP Revolving Credit Facility and had $16.2 million of borrowing capacity. Other. The Company has various other obligations including ship, equipment and facility mortgages. These obligations have maturities ranging from several months through 2029, have interest rates ranging from 2.7% to 4.6% as of December 31, 2016 , and require periodic payments of interest and principal. During the years ended December 31, 2016 , 2015 and 2014 , proceeds from the issuance of other debt was $53.8 million , $4.9 million and $26.9 million , respectively. During the years ended December 31, 2016 , 2015 and 2014 , repayments on other debt and capital leases was $27.5 million , $15.9 million and $29.5 million , respectively. Subsequent to December 31, 2016 , proceeds from the issuance of other debt was $3.4 million . As of December 31, 2016 , the Company had outstanding letters of credit totaling $26.2 million with various expiration dates through 2019 . Additionally, as of December 31, 2016 , the Company had other labor and performance guarantees of $1.9 million . Repurchase Authority. 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. On November 15, 2016 , SEACOR’s Board of Directors increased the Company’s repurchase authority for the Securities to $150.0 million . As of December 31, 2016 , SEACOR had remaining authorization for Securities repurchases of $147.0 million .

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	8. INCOME TAXES Income (loss) before income tax expense (benefit) and equity in earnings (losses) of 50% or less owned companies derived from U.S. and foreign companies for the years ended December 31 were as follows (in thousands): 2016 2015 2014 United States $ (242,375 ) $ (25,441 ) $ 160,782 Foreign (29,200 ) (2,896 ) (5,409 ) Eliminations and other 9,327 (2,461 ) 7,862 $ (262,248 ) $ (30,798 ) $ 163,235 As of December 31, 2016 , cumulative undistributed net earnings of foreign subsidiaries included in the Company’s consolidated retained earnings were $7.9 million . The Company files a consolidated U.S. federal tax return. The components of income tax expense (benefit) for the years ended December 31 were as follows (in thousands): 2016 2015 2014 Current: State $ 5,339 $ 3,155 $ 5,526 Federal (9,260 ) 17,442 56,675 Foreign 5,815 5,971 10,060 1,894 26,568 72,261 Deferred: State (2,568 ) (1,875 ) 196 Federal (93,246 ) (35,539 ) (17,222 ) Foreign 90 (516 ) (38 ) (95,724 ) (37,930 ) (17,064 ) $ (93,830 ) $ (11,362 ) $ 55,197 The following table reconciles the difference between the statutory federal income tax rate for the Company and the effective income tax rate for the years ended December 31 : 2016 2015 2014 Statutory rate (35.0 )% (35.0 )% 35.0 % Non-deductible expenses 0.1 % 1.7 % 0.5 % Noncontrolling interests (2.6 )% (8.1 )% (5.3 )% Losses of foreign subsidiaries not benefited 1.3 % 6.2 % 1.2 % State taxes 0.3 % 0.6 % 2.3 % Other 0.1 % (2.3 )% 0.1 % (35.8 )% (36.9 )% 33.8 % The Company records an additional income tax benefit or expense based on the difference between the fair market value of share awards at the time of grant and the fair market value at the time of vesting or exercise. For the years ended December 31, 2016 and 2015 , an additional net income tax expense was recorded in stockholders’ equity of $2.3 million and $0.1 million , respectively. For the year ended December 31, 2014 , an additional net income tax benefit was recorded in stockholders’ equity of $1.1 million . During the year ended December 31, 2013, the Company provided for income taxes of $10.1 million relating to potential tax exposures surrounding the spin-off of Era Group Inc. (“Era Group”) by means of a dividend to SEACOR’s shareholders of all the issued and outstanding common stock of Era Group (the “Era Spin-off”). As of December 31, 2016 , the Company had combined unrecognized tax benefits on these potential tax exposures and associated accrued interest of $11.7 million , which is included in deferred gains and other liabilities in the accompanying consolidated balance sheets. If recognized, the unrecognized tax benefits would affect the effective tax rate in future periods. Changes in the unrecognized tax benefits may be recorded in future periods as the result of settlement by audit or the expiration of the statute of limitations in September 2017. As of December 31, 2016 , an estimate of the range of the reasonably possible outcomes cannot be made. The components of the net deferred income tax liabilities for the years ended December 31 were as follows (in thousands): 2016 2015 Deferred tax liabilities: Property and equipment $ 257,337 $ 302,529 Long-term debt 46,380 56,110 Unremitted earnings of foreign subsidiaries 24,263 34,977 Investments in 50% or less owned companies 16,549 14,461 Intangible assets 1,908 6,150 Deductible goodwill — 4,124 Other 194 990 Total deferred tax liabilities 346,631 419,341 Deferred tax assets: Share award plans 11,078 11,827 Losses on marketable securities 20,746 8,863 Deductible goodwill 1,611 — Debt and equity issuance costs 7,638 3,029 Other 20,557 8,991 Total deferred tax assets 61,630 32,710 Valuation allowance (3,600 ) (3,357 ) Net deferred tax assets 58,030 29,353 Net deferred tax liabilities $ 288,601 $ 389,988 During the year ended December 31, 2016 , the Company increased its valuation allowance for state net operating loss carryforwards from $3.4 million to $3.6 million . In April 2016, the Internal Revenue Service (“IRS”) selected for examination the Company’s tax return for the year ended December 31, 2014. The examination has been completed and the results of the audit had no material impact on the Company’s consolidated financial position, results of operations or cash flows.

Derivative Instruments And Hedg

Derivative Instruments And Hedging Strategies	12 Months Ended
	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments And Hedging Strategies	9. DERIVATIVE INSTRUMENTS AND HEDGING STRATEGIES Derivative instruments are classified as either assets or liabilities based on their individual fair values. The fair values of the Company’s derivative instruments as of December 31 were as follows (in thousands): 2016 2015 Derivative Asset (1) Derivative Liability (2) Derivative Asset (1) Derivative Liability (2) Derivatives designated as hedging instruments: Forward currency exchange contracts (fair value hedges) $ — $ 316 $ — $ — Interest rate swap agreements (cash flow hedges) — 73 — — — 389 — — Derivatives not designated as hedging instruments: Exchange option liability on subsidiary convertible senior notes — 19,436 — 5,611 Options on equities and equity indices — — — 4,005 Forward currency exchange, option and future contracts 195 194 — 57 Interest rate swap agreements — — — 242 Exchange traded commodity swap, option and future contracts: 1,042 598 469 981 1,237 20,228 469 10,896 $ 1,237 $ 20,617 $ 469 $ 10,896 ______________________ (1) Included in other receivables in the accompanying consolidated balance sheets. (2) Included in other current liabilities in the accompanying consolidated balance sheets, except for the exchange option liability on subsidiary convertible senior notes. Fair Value Hedges. From time to time, the Company may designate certain of its foreign currency exchange contracts as fair value hedges in respect of capital commitments denominated in foreign currencies. By entering into these foreign currency exchange contracts, the Company may fix a portion of its capital commitments denominated in foreign currencies in U.S. dollars to protect against currency fluctuations. As of December 31, 2016 , the Company had euro denominated forward currency exchange contracts with an aggregate U.S. dollar equivalent of $3.9 million related to offshore support vessels scheduled to be delivered in 2017. During the year ended December 31, 2016 , the Company recognized losses on the fair value of these contracts of $0.8 million which was included as an increase to the corresponding hedged equipment included in construction in progress in the accompanying consolidated balance sheets. Cash Flow Hedges. The Company and certain of its 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 and its 50% or less owned companies have converted the variable LIBOR or EURIBOR 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 $2.5 million , $1.3 million and $0.1 million for the years ended December 31, 2016 , 2015 and 2014 , respectively, as a component of other comprehensive loss. As of December 31, 2016 , the interest rate swaps held by the Company and its 50% or less owned companies were as follows: • The Company had two interest rate swap agreements maturing in 2021 that call for the Company to pay a fixed rate of interest of (0.03)% on the aggregate notional value of €15.0 million ( $15.8 million ) and receive a variable interest rate based on EURIBOR on the aggregate notional value. • 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 $105.5 million and receive a variable interest rate based on LIBOR on the aggregate amortized notional value. Subsequent to December 31, 2016 , MexMar entered into another interest rate swap agreement with a maturity in 2023 that calls for MexMar to pay a fixed rate of interest of 2.10% on the notional value of $18.2 million and receive a variable interest rate based on LIBOR on the 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 $23.3 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 $20.6 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 $30.3 million and receive a variable interest rate based on LIBOR on the amortized notional value. Other Derivative Instruments. The Company recognized gains (losses) on derivative instruments not designated as hedging instruments for the years ended December 31 as follows (in thousands): Derivative gains (losses), net 2016 2015 2014 Exchange option liability on subsidiary convertible senior notes $ (13,826 ) $ 2,900 $ — Options on equities and equity indices 3,095 (3,200 ) 38 Forward currency exchange, option and future contracts (378 ) (519 ) (183 ) Interest rate swap agreements (18 ) (18 ) (176 ) Commodity swap, option and future contracts: Exchange traded 902 (2,744 ) (4,250 ) Non-exchange traded — 1,485 669 $ (10,225 ) $ (2,096 ) $ (3,902 ) The exchange option liability relates to a bifurcated embedded derivative in the Company’s 3.75% Subsidiary Convertible Senior Notes (see Notes 7 and 10). 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 December 31, 2016 , the outstanding forward currency exchange contracts translated into a net purchase of foreign currencies with an aggregate U.S. dollar equivalent of $3.8 million . As of December 31, 2016 , the fair market value of the outstanding forward currency option contracts was an unrealized gain of $0.2 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 months to eighteen months . Certain of the Company’s 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 December 31, 2016 , the interest rate swaps held by the Company’s 50% or less owned companies were as follows: • 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 $38.0 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 $74.0 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 enter and settle 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 December 31, 2016 , the net market exposure to these commodities under these contracts was not material.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	10. 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 December 31 that are measured at fair value on a recurring basis were as follows (in thousands): Level 1 Level 2 Level 3 2016 ASSETS Marketable securities (1) $ 116,276 $ — $ — Derivative instruments (included in other receivables) 1,042 195 — Construction reserve funds 153,962 — — LIABILITIES Short sales of marketable securities 1,274 — — Derivative instruments (included in other current liabilities) 598 583 — Exchange option liability on subsidiary convertible senior notes — — 19,436 2015 ASSETS Marketable securities (1) $ 138,200 $ — $ — Derivative instruments (included in other receivables) 469 — — Construction reserve funds 255,408 — — LIABILITIES Short sales of marketable securities 4,827 — — Derivative instruments (included in other current liabilities) 4,986 299 — Exchange option liability on subsidiary convertible senior notes — — 5,611 ______________________ (1) Marketable security gains (losses), net include losses of $34.0 million , losses of $1.4 million and gains of $0.3 million for the years ended December 31, 2016 , 2015 and 2014 , respectively, related to marketable security positions held by the Company as of December 31, 2016 . Marketable security gains (losses), net include gains of $1.5 million and $0.3 million for the years ended December 31, 2015 and 2014 , respectively, related to marketable security positions held by the Company as of December 31, 2015 . The fair value of the exchange option liability on the 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. The Company used a binomial lattice model to estimate the fair value of the exchange option on the subsidiary convertible senior notes that assumes the holders will maximize their value by finding the optimal decision between redeeming at the redemption price or exchanging into shares of Common Stock. This model determines the fair value of the exchange option embedded in the subsidiary convertible senior notes as the differential in the fair value of the notes including the exchange option compared with the fair value of the notes excluding the exchange option. The indicated value of the exchange option was then multiplied by the probability of the SMHI Spin-off to determine the recorded fair value of the exchange option liability. The significant unobservable input used in the fair value measurement is the probability assessment of a SMHI Spin-off. Holding the observable inputs constant, an increase in the probability of a SMHI Spin-off to 100% would result in no value being assigned to the exchange option liability. The significant observable inputs used in the fair value measurement as of December 31 were as follows: 2016 2015 Price of Common Stock $ 71.28 $ 52.56 Risk-free interest rate 2.08 % 2.08 % Estimated Common Stock volatility 30.80 % 24.80 % Estimated SEACOR credit spread 5.63 % 8.26 % For the year ended December 31, 2016, the estimated fair value of the exchange option liability increased by $13.8 million primarily as a result of the increase in the price of Common Stock (see Notes 7 and 9). The estimated fair value of the Company’s other financial assets and liabilities as of December 31 were as follows (in thousands): Carrying Amount Level 1 Level 2 Level 3 2016 ASSETS Cash, cash equivalents and restricted cash $ 403,355 $ 403,355 $ — $ — Investments, at cost, in 50% or less owned companies (included in other assets) 4,432 see below Notes receivable from third parties (included in other receivables and other assets) 12,342 see below LIABILITIES Long-term debt, including current portion (1) 1,032,373 — 1,062,160 — 2015 ASSETS Cash and cash equivalents $ 530,009 $ 530,009 $ — $ — 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) 24,587 see below LIABILITIES Long-term debt, including current portion (1) 1,070,390 — 1,043,576 — ______________________ (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, cash equivalents and restricted cash approximates fair value. The fair value of the Company’s long-term debt was estimated based upon quoted market prices or by using discounted cash flow analyses based on estimated current rates for similar types of arrangements. It was not practicable to estimate the fair value of certain 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 certain of the Company’s notes receivable from third parties as the overall returns are uncertain due to certain provisions for additional payments contingent upon future events. Considerable judgment was required in developing certain of the estimates of fair value and, accordingly, the estimates presented herein are not necessarily indicative of the amounts that the Company could realize in a current market exchange. The Company’s non-financial assets that were measured at fair value during the years ended December 31 were as follows (in thousands): Level 1 Level 2 Level 3 2016 ASSETS Property and equipment: Anchor handling towing supply $ — $ 2,600 $ 42,500 Liftboats — — 62,830 Specialty — 4,000 — Other — 3,003 1,800 Goodwill — — 28,506 Investments, at cost, in 50% or less owned companies (included in other assets) — 3,600 — Investment, at equity, and advances in 50% or less owned companies — 3,438 48,150 Notes receivable from third parties (included in other assets) — — 11,900 2015 ASSETS Property and equipment $ — $ 200 $ — Investment, at equity, and advances in 50% or less owned companies 102,509 6,802 39,201 Property and equipment. During the year ended December 31, 2016 , the Company recognized impairment charges of $120.8 million associated with certain Offshore Marine Services’ offshore support vessels and certain Inland River Services’ equipment currently under construction (see Note 1). The Level 2 fair values were determined based on the contracted sales prices of the property and equipment, sales prices of similar property and equipment or scrap value, as applicable. The Level 3 fair values were determined based on third-party valuations using significant inputs that are unobservable in the market. Due to limited market transactions, the primary valuation methodology applied by the appraisers was an estimated cost approach less estimated economic depreciation for comparably aged and conditioned assets less estimated economic obsolescence based on market data or utilization and rates per day worked trending of the vessel class over the prior two years compared with 2014. The significant unobservable inputs used in the fair value measurement for the anchor handling towing supply fleet were the estimated construction costs for similar new equipment of $364.0 million , estimated economic fleet depreciation of 55% based on average expected remaining useful life and estimated economic obsolescence of 74% . The significant unobservable inputs used in the fair value measurement for the liftboat fleet were the estimated construction costs for similar new equipment of $279.0 million , estimated economic fleet depreciation of 42% based on average expected remaining useful life and estimated average economic obsolescence of 61% . During the year ended December 31, 2015 , the Company recognized impairment charges of $6.6 million related to the suspended construction of two offshore support vessels. The fair value of the construction in progress was determined based on the scrap value of the hulls. Goodwill. During the year ended December 31, 2016 , the Company recognized goodwill impairment charges of $19.6 million following a restructuring of Witt O’Brien’s (see Note 1). The fair value of Witt O’Brien’s was based on an appraisal performed in conjunction with the Company’s annual impairment test of goodwill on October 1, 2016 using significant inputs that are unobservable in the market and therefore are considered a Level 3 fair value measurement. The significant unobservable inputs used in the fair value measurement were industry transactions, cash flow projections and discount rates. The appraisal utilized both a market approach based on implied revenues and earnings multiples from industry transactions occurring in the prior five years and an income approach based on a discounted cash flow analysis of projected operating results, investment needs and capital expenditures, to establish value. The income approach was weighted more heavily based on the recent strategic growth program and management’s projected financial data. Under the income approach, fair value was determined by discounting the estimated future cash flows over a discrete period using an estimated weighted average cost of capital. The assumptions and estimates underlying the annual impairment assessment, such as the timing and extent of natural and man-made disasters, associated revenue and operating expenses are highly judgmental. Investments, at cost, in 50% or less owned companies. During the year ended December 31, 2016 , the Company identified indicators of impairment in a Shipping Services cost investment in a foreign container shipping company and an Other cost investment in a foreign industrial aircraft company and, as a consequence, recognized impairment charges of $11.6 million for an other-than-temporary decline in fair value. The Level 2 fair value of the Shipping Services cost investment was based on the value of the common stock issued in a recent offering. The Other cost investment was determined to have an immaterial value. Investments, at equity, and advances in 50% or less owned companies. During the year ended December 31, 2016 , the Company marked its investments to fair value in certain of its 50% or less owned companies as follows: • the Company identified indicators of impairment in one of Offshore Marine Services’ other equity method investments as a result of continuing weak market conditions and, as a consequence, recognized a $0.5 million impairment charge, net of tax, for an other-than-temporary decline in fair value. The investment was determined to have no value and the Company has suspended equity method accounting (see Note 4); • the Company identified indicators of impairment in its investment in Falcon Global as a result of continuing weak market conditions and, as a consequence, recognized a $6.4 million impairment charge, net of tax, for an other-than-temporary decline in fair value. Falcon Global’s primary assets consist of two liftboats in the final stages of construction and the estimated fair value of the liftboats was the primary input used by the Company in determining the fair value of its investment (see Note 4) and resulting impairment charge. The fair value of the liftboats was determined based on a third-party valuation using significant inputs that are unobservable in the market and therefore are considered a Level 3 fair value measurement. Due to limited market transactions, the primary valuation methodology applied by the appraisers was an estimated cost approach less economic obsolescence based on utilization and rates per day worked trending over the prior year in the Middle East region where the vessels are intended to operate. The significant unobservable inputs used in the fair value measurement were the estimated construction costs of similar new equipment and economic obsolescence of 25% ; • the Company identified indicators of impairment in its investment in SCFCo as a result of continuing losses and the expectation of continuing weak market conditions and, as a consequence, recognized a $7.7 million impairment charge for an other-than-temporary decline in the fair value of its investment. The fair value of the Company’s investment in SCFCo is estimated with significant inputs that are both observable and unobservable in the market and therefore is considered a Level 3 fair value measurement. The significant unobservable inputs used in the fair value measurement were an estimated earnings multiple of 7 x applied to 2017 forecasted cash flows before interest, taxes, depreciation and amortization (see Note 4); and • the Company marked its investment in SeaJon II to fair value as a consequence of acquiring its partner’s interest resulting in a $1.9 million impairment charge, net of tax, based on the fair value of the acquired interest (see Notes 2 and 4). During the year ended December 31, 2015 , the Company marked its investments to fair value in certain of its 50% or less owned companies as follows: • on December 21, 2015, the Company determined it no longer exercised significant influence over Dorian (see Note 4) and marked its investment, at equity, to fair value. The Level 1 fair value was determined based on the closing quoted market price for Dorian on that date; • the Company marked its equity investment in VA&E to fair value upon the deconsolidation of a previously controlled subsidiary following its contribution to VA&E. The Level 2 fair value was determined based on the value of the equity investment the Company received; and • the Company identified indicators of impairment in its investment in SCFCo as a result of continuing losses and the expectation of continuing weak market conditions and, as a consequence, recognized a $21.5 million impairment charge for an other-than-temporary decline in the fair value of its investment. The fair value of the Company’s investment in SCFCo is estimated with significant inputs that are both observable and unobservable in the market and therefore is considered a Level 3 fair value measurement. The significant unobservable inputs used in the fair value measurement were the construction and mobilization costs of similar new equipment, estimated economic depreciation for comparably aged assets and earnings multiples applied to historical and forecasted cash flows (see Note 4). Notes receivable from third parties. During the year ended December 31, 2016 , the Company recorded $8.5 million in reserves for two of its notes receivables from third parties following non-performance and a decline in the underlying collateral values. The collateral for a note receivable of $6.7 million was determined to have no value. The Company recorded a reserve of $1.8 million for the other note receivable based on a third-party valuation of the underlying collateral using significant inputs that are unobservable in the market and therefore are considered a Level 3 fair value measurement. Due to limited market transactions, the primary valuation methodology applied by the appraiser was an estimated cost approach less estimated economic depreciation for comparably aged assets and less estimated economic obsolescence. The significant unobservable inputs used in the fair value measurement were the estimated construction costs for similar new equipment, estimated economic depreciation of 33% and estimated economic obsolescence of 56% (see Note 6).

Common Stock Common Stock (Note

Common Stock Common Stock (Notes)	12 Months Ended
	Dec. 31, 2016
Treasury Stock Transactions, Excluding Value of Shares Reissued [Abstract]
Common Stock Disclosure [Text Block]	11. STOCK REPURCHASES SEACOR’s Board of Directors previously approved a securities repurchase plan that authorizes the Company to acquire its Securities, which may be acquired through open market purchases, privately negotiated transactions or otherwise, depending on market conditions. During the year ended December 31, 2016 , the Company acquired no shares of Common Stock for treasury under the Securities repurchase plan. During the years ended December 31, 2015 and 2014 , the Company acquired for treasury 1,162,955 and 2,531,324 shares of Common Stock, respectively, for an aggregate purchase price of $72.4 million and $195.3 million , respectively. On November 15, 2016 , SEACOR’s Board of Directors increased the Company’s repurchase authority for the Securities to $150.0 million . As of December 31, 2016 , SEACOR had remaining authorization for Securities repurchases of $147.0 million . During the years ended December 31, 2016 and 2015 , the Company acquired for treasury 47,455 and 40,859 shares of Common Stock, respectively, for aggregate purchase prices of $2.4 million and $3.0 million , respectively, from its employees to cover their tax withholding obligations upon the lapsing of restrictions on share awards. During the year ended December 31, 2014 , the Company acquired for treasury 26,792 shares of Common Stock for an aggregate purchase price of $2.0 million upon the exercise of certain stock options by the Company’s Executive Chairman and Chief Executive Officer. 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)	12 Months Ended
	Dec. 31, 2016
Noncontrolling Interest [Abstract]
Noncontrolling Interest Disclosure [Text Block]	12. NONCONTROLLING INTERESTS IN SUBSIDIARIES Noncontrolling interests in the Company’s consolidated subsidiaries as of December 31 were as follows (in thousands): Noncontrolling Interests 2016 2015 Offshore Marine Services: Windcat Workboats 25% $ 5,266 $ 7,484 Other 1.8 % – 30.0% 277 470 Inland River Services: Other 3.0 % – 51.8% 980 1,146 Shipping Services: SEA-Vista 49% 106,054 88,290 Illinois Corn Processing 30% 22,647 22,272 Other 5.0 % – 14.6% 152 457 $ 135,376 $ 120,119 Windcat Workboats. Windcat Workboats Holdings Ltd. (“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 December 31, 2016 and 2015 , the net assets of Windcat Workboats were $21.1 million and $29.9 million , respectively. During the year ended December 31, 2016 , the net loss of Windcat Workboats was $4.5 million , of which $1.1 million was attributable to noncontrolling interests. During the year ended December 31, 2015 , the net income of Windcat Workboats was $1.6 million , of which $0.4 million was attributable to noncontrolling interests. During the the year ended December 31, 2014 , the net income of Windcat Workboats was $1.9 million , of which $0.5 million was attributable to noncontrolling interests. Inland River Services. During the year ended December 31, 2014, the Company acquired the noncontrolling interest in one of its Inland River Services partnerships for $3.1 million ( $2.1 million in cash and $1.0 million through the distribution of an inland river towboat to the noncontrolling interest holder). SEA-Vista. On May 2, 2014, the Company issued a 49% noncontrolling interest to a financial investor in SEA-Vista for $145.7 million , net of $3.2 million in issue costs. SEA-Vista owns and operates the Company’s fleet of U.S.-flag product tankers used on the U.S. coastwise trade of crude oil, petroleum and specialty chemical products and holds a contract for the construction of one 50,000 DWT (deadweight tonnage) product tanker. As of December 31, 2016 and 2015 , the net assets of SEA-Vista were $216.4 million and $180.2 million , respectively. During the year ended December 31, 2016 , the net income of SEA-Vista was $36.3 million , of which $17.8 million was attributable to noncontrolling interests. During the year ended December 31, 2015 , the net income of SEA-Vista was $5.2 million , of which $2.6 million was attributable to noncontrolling interests. From May 2, 2014 through December 31, 2014 , the net income of SEA-Vista was $25.1 million , of which $12.3 million was attributable to noncontrolling interests. Illinois Corn Processing. ICP owns and operates an alcohol manufacturing, storage and distribution facility located in Pekin, IL. As of December 31, 2016 and 2015 , the net assets of ICP were $75.5 million and $74.2 million , respectively. During the year ended December 31, 2016 , the net income of ICP was $12.3 million , of which $3.7 million was attributable to noncontrolling interests. During the year ended December 31, 2015 , the net income of ICP was $19.5 million , of which $5.9 million was attributable to noncontrolling interests. During the the year ended December 31, 2014 , the net income of ICP was $38.4 million , of which $10.3 million was attributable to noncontrolling interests. For the twelve months ending March 31, 2014, the noncontrolling member of ICP had invoked a plant shutdown election that is available to each LLC member under certain circumstances; however, under its member rights, the Company elected to keep the plant in operation. As a result, the earnings and losses of ICP were disproportionately allocated to its members during the plant shutdown election period. Effective April 1, 2014, the noncontrolling member of ICP withdrew its plant shutdown election.

Savings Plans And Multiemployer

Savings Plans And Multiemployer Pension Plans	12 Months Ended
	Dec. 31, 2016
Deferred Compensation Arrangements [Abstract]
Savings Plans And Multiemployer Pension Plans	13. SAVINGS AND MULTI-EMPLOYER PENSION PLANS SEACOR Savings Plan. The Company provides a defined contribution plan (the “Savings Plan”) for its eligible U.S.-based employees. The Company’s contribution to the Savings Plan is limited to 3.5% of an employee’s wages depending upon the employee’s level of voluntary wage deferral into the Savings Plan and is subject to annual review by the Board of Directors of SEACOR. The Company’s Savings Plan costs were $1.8 million , $3.8 million and $2.4 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. SEACOR Marine Savings Plan. Beginning on January 1, 2016, SMHI provides a defined contribution plan (the “SMHI Savings Plan”) for its eligible U.S.-based employees. SMHI does not contribute to the SMHI Savings Plan. The SMHI Savings Plan costs for the year ended December 31, 2016 were not material. SEACOR Deferred Compensation Plan. In 2005, the Company established a non-qualified deferred compensation plan, as amended (the “Deferred Compensation Plan”) to provide certain highly compensated executives and non-employee directors the ability to defer receipt of up to 75% of their cash base salary and up to 100% of their cash bonus. Prior to a 2012 amendment, participants were eligible to defer up to 100% of their vested restricted stock (deferred in the form of Restricted Stock Units, as defined in the plan) for each fiscal year. Each participant’s compensation deferrals are credited to a bookkeeping account and, subject to certain restrictions, each participant may elect to have their cash deferrals in such account indexed against one or more investment options, solely for purposes of determining amounts payable under the Deferred Compensation Plan (the Company is not obligated to actually invest any deferred amounts in the selected investment options). Participants may receive a distribution of deferred amounts, plus any earnings thereon (or less any losses), on a date specified by the participant or, if earlier, upon a separation from service or upon a change of control (as defined). All distributions to participants following a separation from service shall be in the form of a lump sum, except if such separation qualifies as “retirement” under the terms of the plan, in which case it may be paid in installments if previously elected by the participant. Distributions to “Key Employees” upon a separation from service (other than due to death) will not commence until at least six months after the separation from service. Participants are always 100% vested in the amounts they contribute to their Deferred Compensation Plan accounts. The Company, at its option, may contribute amounts to participants’ accounts, which may be subject to vesting requirements. The obligations of the Company to pay deferred compensation under the Deferred Compensation Plan are general unsecured obligations of the Company and rank equally with other unsecured indebtedness of the Company that is outstanding from time to time. As of December 31, 2016 and 2015 , the Company had obligations of $0.4 million and $0.3 million , respectively, related to the Deferred Compensation Plan that are included in the accompanying consolidated balance sheets as deferred gains and other liabilities. The total amount of the Company’s obligation under the Deferred Compensation Plan will vary depending upon the level of participation by participants and the amount of compensation that participants elect to defer under the plan. The duration of the Deferred Compensation Plan is indefinite (subject to the Board of Directors’ discretion to amend or terminate the plan). MNOPF and MNRPF. Certain subsidiaries of the Company are participating employers in two industry-wide, multi-employer, defined benefit pension funds in the United Kingdom: the United Kingdom Merchant Navy Officers Pension Fund (“MNOPF”) and the United Kingdom Merchant Navy Ratings Pension Fund (“MNRPF”). The Company’s participation in the MNOPF and MNRPF began with SEACOR’s acquisition of the Stirling group of companies in 2001 and relates to the current and former employment of certain officers and ratings by the Company and/or Stirling’s predecessors from 1978 through today. Both of these plans are in deficit positions and, depending upon the results of future actuarial valuations, it is possible that the plans could experience funding deficits that will require the Company to recognize payroll related operating expenses in the periods invoices are received. Under the direction of a court order, any funding deficit of the MNOPF is to be remedied through funding contributions from all participating current and former employers. Prior to 2014, the Company was invoiced and expensed $19.4 million for its allocated share of the then cumulative funding deficits, including portions deemed uncollectible due to the non-existence or liquidation of certain former employers. The cumulative funding deficits of the MNRPF were being recovered by additional annual contributions from current employers that were subject to adjustment following the results of tri-annual actuarial valuations. Prior to 2014, the Company was invoiced and expensed $0.4 million for its allocated share of the then cumulative funding deficits. On February 25, 2015, the High Court approved a new deficit contribution scheme whereby any funding deficit of the MNRPF is to be remedied through funding contributions from all participating current and former employers. Based on an actuarial valuation in 2014, the cumulative funding deficit of the MNRPF was $491.7 million ( £325.0 million ). On August 28, 2015, the Company was invoiced and recognized payroll related operating expenses of $6.9 million ( £4.5 million ) for its allocated share of the cumulative funding deficit, including portions deemed uncollectible due to the non-existence or liquidation of certain former employers. The invoiced amounts are payable in four annual installments beginning in October of 2015. AMOPP and SPP. Certain subsidiaries of the Company are participating employers in two industry-wide, multi-employer defined benefit pension plans and one industry-wide, multi-employer defined contribution plan: the American Maritime Officers Pension Plan (the “AMOPP” - EIN: 13-1936709); the Seafarers Pension Plan (the “SPP” - EIN: 13-6100329); and the American Maritime Officers Defined Contribution Plan (the “AMODCP” - EIN: 27-1269640). The Company’s participation in these plans relates to certain employees of the Company’s Shipping Services business segment. Under federal pension law, the AMOPP was deemed in critical status for the 2009 and 2010 plan years. The AMOPP was frozen in January 2010 and a ten year rehabilitation plan was adopted by the AMOPP trustees in February 2010 whereby benefit changes and increased contributions by participating employers were expected to improve the funded status of the AMOPP. The AMOPP was replaced by the AMO 401(k) Plan. On December 28, 2012, the AMOPP was elevated to endangered status primarily as a result of favorable investment performance and the rehabilitation plan adopted by the AMOPP trustees. Based on an actuarial valuation performed as of September 30, 2014, the latest period for which an actuarial valuation is available, if the Company chose to fully withdraw from the AMOPP at that time, its withdrawal liability would have been $39.9 million . That liability may change in future years based on various factors, primarily employee census. As of December 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. The SPP was neither in endangered or critical status for the 2014 plan year, the latest period for which a report is available, as the SPP was fully funded. In accordance with collective bargaining agreements between the Company and the American Maritime Officers (“AMO”), the latest of which expires on December 31, 2018, and the Seafarers International Union (“SIU”), the latest of which expires on September 30, 2018, the Company makes periodic contributions to the AMOPP, SPP and AMO 401(k) Plan. The contributions to these plans are expensed as incurred and are included in operating expenses in the accompanying consolidated statements of income (loss). During the years ended December 31, 2016 , 2015 and 2014 , the Company made contributions of $1.4 million , $1.1 million and $1.1 million , respectively, to the AMOPP and AMO 401(k) Plan, and $1.9 million , $1.6 million and $1.5 million , respectively to the SPP. During the years ended December 31, 2016 , 2015 and 2014 , none of the Company’s contributions to the AMOPP or the SPP exceeded 5% of total contributions to the plans and the Company did not pay any material surcharges. As of December 31, 2016 , there is no required minimum future contribution to the AMOPP or the SPP. The Company’s obligations for future contributions are based upon the number of employees subject to the collective bargaining agreements, their rates of pay and the number of days worked. Future negotiations of collective bargaining agreements between the Company and the participating unions, including the contribution levels for the defined benefit pension and contribution plans, may result in increases to the Company’s wage and benefit costs and those increases may be material. Other Plans. Certain employees participate in other defined contribution plans in various international regions including the United Kingdom and Singapore. During the years ended December 31, 2016 , 2015 and 2014 , the Company incurred costs of $0.7 million , $0.7 million and $0.7 million , respectively, in the aggregate related to these plans, primarily from employer matching contributions.

Share Based Compensation

Share Based Compensation	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share Based Compensation	14. SHARE BASED COMPENSATION Share Incentive Plans. SEACOR’s stockholders approved the 2014 Share Incentive Plan to provide for the grant of options to purchase shares of Common Stock, stock appreciation rights, restricted stock, stock awards, performance awards and restricted stock units to non-employee directors, key officers and employees of the Company. The 2014 Share Incentive Plan superseded the 2007 Share Incentive Plan, the 2003 Non-Employee Director Share Incentive Plan and the 2003 Share Incentive Plan (collectively including all predecessor plans, the “Share Incentive Plans”). The Compensation Committee of the Board of Directors administers the Share Incentive Plans. A total of 6,650,000 shares of Common Stock have been authorized for grant under the Share Incentive Plans. All shares issued pursuant to such grants are newly issued shares of Common Stock. The exercise price per share of options granted cannot be less than 100% of the fair market value of Common Stock at the date of grant under the Share Incentive Plans. Grants to date have been limited to stock awards, restricted stock, restricted stock units and options to purchase shares of Common Stock. Restricted stock and restricted stock units typically vest from one to five years after date of grant and options to purchase shares of Common Stock typically vest and become exercisable from one to five years after date of grant. Options to purchase shares of Common Stock granted under the Share Incentive Plans expire no later than the tenth anniversary of the date of grant. In the event of a participant’s death, retirement, termination by the Company without cause or a change in control of the Company, as defined in the Share Incentive Plans, restricted stock and restricted stock units vest immediately and options to purchase shares of Common Stock vest and become immediately exercisable. Employee Stock Purchase Plans. SEACOR’s stockholders approved the 2009 Employee Stock Purchase Plan with a term of ten years (collectively including all predecessor plans, the “Employee Stock Purchase Plans”) to permit the Company to offer Common Stock for purchase by eligible employees at a price equal to 85% of the lesser of (i) the fair market value of Common Stock on the first day of the offering period or (ii) the fair market value of Common Stock on the last day of the offering period. Common Stock is made available for purchase under the Employee Stock Purchase Plans for six -month offering periods. The Employee Stock Purchase Plans are intended to comply with Section 423 of the Internal Revenue Code of 1986, as amended (the “Code”), but is not intended to be subject to Section 401(a) of the Code or the Employee Retirement Income Security Act of 1974. The Board of Directors of SEACOR may amend or terminate the Employee Stock Purchase Plans at any time; however, no increase in the number of shares of Common Stock reserved for issuance under the Employee Stock Purchase Plans may be made without stockholder approval. A total of 600,000 shares of Common Stock have been approved for purchase under the Employee Stock Purchase Plans with all shares issued from those held in treasury. Share Award Transactions. The following transactions have occurred in connection with the Company’s share based compensation plans during the years ended December 31: 2016 2015 2014 Restricted stock awards granted 137,258 135,150 150,145 Restricted stock awards forfeited (2,867 ) — (1,325 ) Director stock awards granted 3,125 3,375 2,625 Restricted Stock Unit Activities: Shares released from Deferred Compensation Plan — (217 ) (216 ) Stock Option Activities: Outstanding as of the beginning of year 1,690,899 1,546,508 1,481,280 Granted 197,550 192,350 199,100 Exercised (113,820 ) (40,461 ) (133,872 ) Forfeited (18,760 ) — — Expired (116,004 ) (7,498 ) — Outstanding as of the end of year 1,639,865 1,690,899 1,546,508 Employee Stock Purchase Plans shares issued 41,924 39,384 30,622 Shares available for issuance under Share Incentive and Employee Stock Purchase Plans as of the end of year 522,341 764,567 1,127,328 During the years ended December 31, 2016 , 2015 and 2014 , the Company recognized $14.1 million , $14.9 million and $15.3 million , respectively, of compensation expense related to stock awards, stock options, employee stock purchase plans purchases, restricted stock and restricted stock units (collectively referred to as “share awards”). As of December 31, 2016 , the Company had approximately $26.7 million in total unrecognized compensation costs of which $11.0 million and $8.3 million are expected to be recognized in 2017 and 2018 , respectively, with the remaining balance recognized through 2021 . The weighted average values of grants under the Company’s Share Incentive Plans were $31.31 , $41.09 and $53.03 for the years ended December 31, 2016 , 2015 and 2014 , respectively. The fair value of each option granted during the years ended December 31, 2016 , 2015 and 2014 , is estimated on the date of grant using the Black-Scholes option-pricing model with the following assumptions: (a) no dividend yield, (b) weighted average expected volatility of 26.5% , 25.2% and 29.4% , respectively, (c) weighted average discount rates of 1.59% , 1.79% and 1.85% , respectively, and (d) expected lives of 6.25 years, 6.03 years and 5.92 years, respectively. During the year ended December 31, 2016 , the number of shares and the weighted average grant price of restricted stock transactions were as follows: Restricted Stock Number of Shares Weighted Average Grant Price Nonvested as of December 31, 2015 387,878 $ 76.93 Granted 137,258 $ 51.10 Vested (141,457 ) $ 76.37 Forfeited (2,867 ) $ 64.49 Nonvested as of December 31, 2016 380,812 $ 67.92 During the years ended December 31, 2016 , 2015 and 2014 , the total grant date fair value of restricted stock that vested was $10.8 million , $10.8 million and $3.7 million , respectively. During the year ended December 31, 2016 , the number of shares, the weighted average grant date fair value and the weighted average exercise price on stock option transactions were as follows: Nonvested Options Vested/Exercisable Options Total Options Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Exercise Price Number of Shares Weighted Average Exercise Price Outstanding, as of December 31, 2015 571,224 $ 22.83 1,119,675 $ 57.64 1,690,899 $ 62.70 Granted 197,550 $ 17.09 — $ — 197,550 $ 57.52 Vested (219,542 ) $ 22.98 219,542 $ 71.76 — $ — Exercised — $ — (113,820 ) $ 48.58 (113,820 ) $ 48.58 Forfeited (18,760 ) $ 22.72 — $ — (18,760 ) $ 71.90 Expired — $ — (116,004 ) $ 60.85 (116,004 ) $ 60.85 Outstanding, as of December 31, 2016 530,472 $ 20.63 1,109,393 $ 61.03 1,639,865 $ 63.09 During the years ended December 31, 2016 , 2015 and 2014 , the aggregate intrinsic value of exercised stock options was $1.4 million , $1.0 million and $5.1 million , respectively. As of December 31, 2016 , the weighted average remaining contractual term for total outstanding stock options and vested/exercisable stock options was 5.14 and 3.80 years, respectively. As of December 31, 2016 , the aggregate intrinsic value of all options outstanding and all vested/exercisable options outstanding was $17.2 million and $13.5 million , respectively.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Related Party Transactions	15. RELATED PARTY TRANSACTIONS The Company manages barge pools as part of its Inland River Services segment. Pursuant to the pooling agreements, operating revenues and expenses of participating barges are combined and the net results are allocated on a pro-rata basis based on the number of barge days contributed by each participant. Companies controlled by Mr. Fabrikant, the Executive Chairman and Chief Executive Officer of SEACOR, and trusts established for the benefit of Mr. Fabrikant’s children, own barges that participate in the barge pools managed by the Company. Mr. Fabrikant and his affiliates were participants in the barge pools prior to the acquisition of SCF Marine Inc. by SEACOR in 2000. During the years ended December 31, 2016 , 2015 and 2014 , Mr. Fabrikant and his affiliates earned $0.8 million , $1.3 million and $1.7 million , respectively, of net barge pool results (after payment of $0.1 million , $0.1 million and $0.2 million , respectively, in management fees to the Company). As of December 31, 2016 and 2015 , the Company owed Mr. Fabrikant and his affiliates $0.5 million and $0.6 million , respectively, for undistributed net barge pool results. ICP manufactures and sells certain non-ethanol alcohol finished goods to the noncontrolling interest partner in ICP. During the years ended December 31, 2016 , 2015 and 2014 , the Company sold $27.7 million , $38.9 million and $36.3 million , respectively to the noncontrolling interest partner. As of December 31, 2016 and 2015 , ICP had accounts receivable of $3.4 million and $2.4 million from the noncontrolling interest partner. In December 2014 and January 2015, Mr. Fabrikant, Mr. Lorentzen, SEACOR's then CEO, and Mr. Gellert invested in newly formed limited liability companies that acquired limited partnership interests in OSV Partners from two limited partners of OSV Partners that are not affiliated with the Company and wished to dispose of their interests. Messrs. Fabrikant, Lorentzen and Gellert each invested $0.2 million in the aggregate in the newly formed limited liability companies. The aggregate interests of OSV Partners acquired indirectly by Messrs. Fabrikant, Lorentzen and Gellert represents 1.7% of the limited partnership interests of OSV Partners. Certain subsidiaries of SEACOR own 30.4% of OSV Partners’ limited partnership interests and the balance of such interests are owned by unaffiliated third parties. The general partner of OSV Partners is a joint venture managed by a subsidiary of SEACOR and an unaffiliated third party. Mr. Fabrikant is also a director of Diamond Offshore Drilling, Inc. (“Diamond”), which is also a customer of the Company. The total amount earned from business conducted with Diamond did not exceed $5.0 million during the years ended December 31, 2016 , 2015 and 2014 . Mr. Fabrikant is also a director of Era Group, which is also a customer of the Company. The Company has provided certain transition services to Era Group related to the Era Spin-off and the total amount earned from business conducted with Era Group, including transition services provided, did not exceed $5.0 million during the years ended December 31, 2016 , 2015 and 2014 . The Company ceased providing transition services to Era Group in June 2015.

Commitments And Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	16. COMMITMENTS AND CONTINGENCIES The Company's capital commitments as of December 31, 2016 by year of expected payment were as follows (in thousands): 2017 2018 2019 2020 Total Offshore Marine Services $ 29,272 $ 50,555 $ 13,223 $ 1,800 $ 94,850 Shipping Services 55,430 — — — 55,430 Inland River Services 30,102 — — — 30,102 Illinois Corn Processing 1,678 375 — — 2,053 $ 116,482 $ 50,930 $ 13,223 $ 1,800 $ 182,435 Offshore Marine Services’ capital commitments included nine fast support vessels, three supply vessels and one wind farm utility vessel. These commitments included $15.4 million for one supply vessel that may be assumed by a third party at their option. Shipping Services' capital commitments included one U.S.-flag product tanker, one U.S.-flag chemical and petroleum articulated tug-barge, three U.S.-flag harbor tugs and two foreign-flag harbor tugs. Inland River Services’ capital commitments included one 30,000 barrel inland river liquid tank barge and three inland river towboats. Subsequent to December 31, 2016 , the Company committed to purchase $0.8 million of additional property and equipment. During 2012, the Company sold National Response Corporation (“NRC”), NRC Environmental Services Inc., SEACOR Response Ltd., and certain other subsidiaries to J.F. Lehman & Company, a leading, middle-market private equity firm (the “SES Business Transaction”). On December 15, 2010, ORM and NRC were named as defendants in one of the several “master complaints” filed in the overall multi-district litigation relating to the Deepwater Horizon oil spill response and clean-up in the Gulf of Mexico pending in the U.S. District Court for the Eastern District of Louisiana (the “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. Both prior to and following the filing of the aforementioned master complaint, individual civil actions naming the Company, ORM, and/or NRC alleging B3 exposure-based injuries and/or damages were consolidated with the MDL and stayed pursuant to court order, discussed in turn below. The Company has continually taken the position that all of the B3 claims asserted against ORM and NRC have no merit. On February 16, 2016, all but eleven B3 claims against ORM and NRC were dismissed 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 continues to evaluate how this ruling will impact the individual civil actions. On April 8, 2016, the Court entered an order establishing a summary judgment briefing schedule as to the remaining eleven B3 claimants (the “Remaining Eleven Plaintiffs”). The Clean-Up Responder Defendants, including ORM and NRC, filed an omnibus motion for summary judgment as to the Remaining Eleven Plaintiffs on May 9, 2016. Following briefing by the parties, on August 2, 2016, the Court granted the omnibus motion as it concerns ORM and NRC in its entirety, dismissing the Remaining Eleven Plaintiffs’ against ORM and NRC with prejudice (the “Remaining Eleven Plaintiffs’ Dismissal Order”). To date, no appeal has been filed and the deadline to appeal has expired. As noted above, various civil actions concerning the Deepwater Horizon clean-up have been consolidated with the MDL and stayed. 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.) (the “ Johnson Action”), 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 March 29, 2016, the Court issued a pretrial order for disclosures clarifying the basis for the non-governmental economic property damage claims asserted in the MDL, termed the “B1” claims, and ordered plaintiffs to come forward with specific information in a sworn statement in support of their claims. On July 14, 2016, the Court dismissed all claimants who had failed to comply with the terms of the aforementioned pretrial order, and the plaintiff in the Johnson Action failed to submit the requisite sworn statement. Liaison Counsel confirmed the dismissal of the Johnson Action in a Status Report submitted to the Court on February 14, 2017. 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.) (the “ Black Action”), which is a suit by an individual who is seeking damages for, among other things, lost income because he allegedly could not find work in the fishing industry after the oil spill and exposure during the spill. The B3 exposure claims against ORM and NRC in the Black Action have been dismissed by virtue of the B3 Dismissal Order. 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. Ms. Sanchez’s B3 claim against ORM has been dismissed by virtue of the B3 Dismissal Order. 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.) (the “ Dillon Action”), 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 March 28, 2017 the Court entered an order dismissing, with prejudice, plaintiffs claims asserted in the Dillon action against ORM. 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.) (the “ Fitzgerald Action”), 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. While the decedent in the Fitzgerald Action’s claims against ORM and NRC were dismissed by virtue of the Remaining Eleven Plaintiffs’ Dismissal Order, the claim as against the Company remains stayed. The Company continues to evaluate the impact of the B3 Dismissal Order, the Remaining Eleven Plaintiffs’ Dismissal Order, and other developments in the MDL, including the settlements discussed below, on these individual actions. A status conference with the Court took place on February 17, 2017 and the Court indicated it will be issuing new pretrial orders in connection with the remaining claims in the MDL. 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. 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. This case was removed to federal court and ultimately 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. This case was 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 developments in the MDL, including the settlements discussed below, on these cases, but believes that the potential exposure, if any, resulting from these matters has been reduced as a result of the B3 Dismissal Order 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. Both settlements were granted final approval by the Court, all appeals have concluded, and the deadline for submitting claims with respect to both settlements has 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 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. During the twelve months ended December 31, 2014, the Company received net litigation settlement proceeds of $14.7 million from an equipment supplier relating to the May 2008 mechanical malfunction and fire onboard the SEACOR Sherman , an anchor handling towing supply vessel then under construction. Upon settlement of the litigation, the Company recognized a gain of $14.7 million , which is included in other income (expense) in the accompanying consolidated statements of income (loss). 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. As of December 31, 2016 , the Company leases eight offshore support vessels, four inland river towboats, six inland river harbor boats, three U.S.-flag product tankers, nine U.S.-flag harbor tugs and certain facilities and other equipment. These leasing agreements have been classified as operating leases for financial reporting purposes and related rental fees are charged to expense over the lease terms. The leases generally contain purchase and lease renewal options or rights of first refusal with respect to the sale or lease of the equipment. The remaining lease terms of the U.S.-flag product tankers, which are subject to subleases, have durations of 69 and 85 months. The lease terms of the other equipment range in duration from one to 17 years. Certain of the equipment leases are the result of sale-leaseback transactions with finance companies (see Note 3) and certain of the gains arising from such sale-leaseback transactions have been deferred in the accompanying consolidated balance sheets and are being amortized as reductions in rental expense over the lease terms (see Note 1). Total rental expense for the Company’s operating leases in 2016 , 2015 and 2014 was $54.6 million , $59.9 million and $66.8 million , respectively. Future minimum payments in the years ended December 31 under operating leases that have a remaining term in excess of one year as of December 31, 2016 were as follows (in thousands): Total Minimum Payments Non-cancelable Subleases (1) Net Minimum Payments 2017 $ 59,014 $ (17,345 ) $ 41,669 2018 58,772 (17,345 ) 41,427 2019 43,836 (17,345 ) 26,491 2020 38,570 (17,392 ) 21,178 2021 28,386 (17,345 ) 11,041 Years subsequent to 2021 31,267 (24,045 ) 7,222 ____________________ (1) The total minimum offsetting payments to be received under existing long-term bareboat charter-out arrangements.

Major Customers And Segment Inf

Major Customers And Segment Information	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Major Customers And Segment Information	17. MAJOR CUSTOMERS AND SEGMENT INFORMATION 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 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the year ended December 31, 2016 Operating Revenues: External customers 215,536 165,140 229,643 177,401 42,783 482 — 830,985 Intersegment 100 2,403 — — 133 — (2,636 ) — 215,636 167,543 229,643 177,401 42,916 482 (2,636 ) 830,985 Costs and Expenses: Operating 166,925 124,460 122,631 158,495 28,561 — (3,259 ) 597,813 Administrative and general 49,308 14,616 27,825 3,011 16,214 1,001 26,606 138,581 Depreciation and amortization 58,069 26,327 31,162 4,299 1,539 — 3,537 124,933 274,302 165,403 181,618 165,805 46,314 1,001 26,884 861,327 Gains (Losses) on Asset Dispositions and Impairments, Net (116,222 ) 3,193 411 — (29,587 ) — — (142,205 ) Operating Income (Loss) (174,888 ) 5,333 48,436 11,596 (32,985 ) (519 ) (29,520 ) (172,547 ) Other Income (Expense): Derivative gains (losses), net 2,995 — — 911 — — (14,131 ) (10,225 ) Foreign currency gains (losses), net (3,312 ) 1,722 (18 ) — (181 ) (1 ) (78 ) (1,868 ) Other, net (1,490 ) (4 ) (6,224 ) — — (12,608 ) 120 (20,206 ) Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax (6,314 ) (15,944 ) (4,697 ) — 305 (704 ) — (27,354 ) Segment Profit (Loss) (183,009 ) (8,893 ) 37,497 12,507 (32,861 ) (13,832 ) Other Income (Expense) not included in Segment Profit (57,402 ) Less Equity in Losses included in Segment Profit 27,354 Loss Before Taxes and Equity Earnings (262,248 ) Capital Expenditures 100,884 36,803 215,837 4,723 2 — 164 358,413 As of December 31, 2016 Property and Equipment: Historical cost 958,759 419,714 727,602 56,708 1,559 — 29,681 2,194,023 Accumulated depreciation (540,619 ) (167,127 ) (258,004 ) (23,689 ) (1,244 ) — (18,184 ) (1,008,867 ) 418,140 252,587 469,598 33,019 315 — 11,497 1,185,156 Construction in progress 123,801 13,003 233,214 701 — — (207 ) 370,512 541,941 265,590 702,812 33,720 315 — 11,290 1,555,668 Investments, at Equity, and Advances to 50% or Less Owned Companies 138,311 69,181 51,620 — 566 54,094 — 313,772 Inventories 3,058 1,602 843 11,133 137 — — 16,773 Goodwill — 2,400 1,852 — 28,506 — — 32,758 Intangible Assets — 12,018 — — 8,060 — — 20,078 Other current and long-term assets, excluding cash and near cash assets (3) 72,810 88,165 29,801 11,850 14,284 11,193 21,576 249,679 Segment Assets 756,120 438,956 786,928 56,703 51,868 65,287 Cash and near cash assets (3) 673,593 Total Assets 2,862,321 ______________________ (1) Operating revenues includes $167.0 million of tangible product sales and operating expenses includes $148.2 million of costs of goods sold. (2) Inventories include raw materials of $1.8 million and work in process of $1.5 million . (3) Cash and near cash assets includes cash, cash equivalents, restricted cash, marketable securities and construction reserve funds. Offshore Marine Services $’000 Inland River Services $’000 Shipping Services $’000 ICP (1)(2) $’000 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the year ended December 31, 2015 Operating Revenues: External customers 368,744 227,601 227,142 166,905 49,838 14,506 — 1,054,736 Intersegment 124 2,881 — — 146 — (3,151 ) — 368,868 230,482 227,142 166,905 49,984 14,506 (3,151 ) 1,054,736 Costs and Expenses: Operating 275,972 168,015 129,039 143,967 21,899 13,054 (3,341 ) 748,605 Administrative and general 53,085 15,567 26,215 2,307 24,096 2,546 32,795 156,611 Depreciation and amortization 61,729 28,632 26,296 3,902 1,711 5 3,712 125,987 390,786 212,214 181,550 150,176 47,706 15,605 33,166 1,031,203 Gains (Losses) on Asset Dispositions and Impairments, Net (17,017 ) 14,868 — — (27 ) (232 ) — (2,408 ) Operating Income (Loss) (38,935 ) 33,136 45,592 16,729 2,251 (1,331 ) (36,317 ) 21,125 Other Income (Expense): Derivative gains (losses), net (2,766 ) 294 — (1,251 ) — (472 ) 2,099 (2,096 ) Foreign currency losses, net (27 ) (3,726 ) (30 ) — (36 ) (11 ) (922 ) (4,752 ) Other, net 261 — 2,053 4,112 19 33 295 6,773 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 8,757 (31,200 ) (18,782 ) — 135 676 — (40,414 ) Segment Profit (Loss) (32,710 ) (1,496 ) 28,833 19,590 2,369 (1,105 ) Other Income (Expense) not included in Segment Profit (51,848 ) Less Equity Losses included in Segment Profit 40,414 Loss Before Taxes and Equity Earnings (30,798 ) Capital Expenditures 87,765 69,736 134,581 4,712 409 — (1,273 ) 295,930 As of December 31, 2015 Property and Equipment: Historical cost 1,102,619 485,144 454,144 47,256 3,338 — 30,700 2,123,201 Accumulated depreciation (546,962 ) (171,271 ) (239,076 ) (19,390 ) (2,834 ) — (14,648 ) (994,181 ) 555,657 313,873 215,068 27,866 504 — 16,052 1,129,020 Construction in progress 97,900 17,807 335,113 5,430 — — (1,645 ) 454,605 653,557 331,680 550,181 33,296 504 — 14,407 1,583,625 Investments, at Equity, and Advances to 50% or Less Owned Companies 130,010 81,363 64,499 — 344 54,887 — 331,103 Inventories 4,000 1,493 701 18,574 — — — 24,768 Goodwill — 2,364 1,852 — 48,124 — — 52,340 Intangible Assets 1,049 5,961 — — 19,382 — — 26,392 Other current and long-term assets, excluding cash and near cash assets (3) 97,488 72,180 28,359 7,739 14,780 16,014 7,014 243,574 Segment Assets 886,104 495,041 645,592 59,609 83,134 70,901 Cash and near cash assets (3) 923,617 Total Assets 3,185,419 ______________________ (1) Operating revenues includes $154.8 million of tangible product sales and operating expenses includes $131.9 million of costs of goods sold. (2) Inventories include raw materials of $2.1 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 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the year ended December 31, 2014 Operating Revenues: External customers 529,761 249,288 214,316 236,293 27,691 62,045 — 1,319,394 Intersegment 183 3,862 — — — — (4,045 ) — 529,944 253,150 214,316 236,293 27,691 62,045 (4,045 ) 1,319,394 Costs and Expenses: Operating 365,092 174,918 112,771 187,849 12,978 59,666 (3,902 ) 909,372 Administrative and general 58,353 15,937 24,518 2,177 19,180 5,957 38,816 164,938 Depreciation and amortization 64,615 29,435 28,420 4,119 1,045 284 3,901 131,819 488,060 220,290 165,709 194,145 33,203 65,907 38,815 1,206,129 Gains (Losses) on Asset Dispositions and Impairments, Net 26,545 29,657 159 — — (1,077 ) (3,306 ) 51,978 Operating Income (Loss) 68,429 62,517 48,766 42,148 (5,512 ) (4,939 ) (46,166 ) 165,243 Other Income (Expense): Derivative gains (losses), net (171 ) — — (3,777 ) — 270 (224 ) (3,902 ) Foreign currency losses, net (1,375 ) (3,335 ) (40 ) — (53 ) (102 ) (1,430 ) (6,335 ) Other, net 14,671 (38 ) (3,630 ) 660 (5,056 ) (3,097 ) (71 ) 3,439 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 10,468 6,673 (661 ) — (465 ) 294 — 16,309 Segment Profit (Loss) 92,022 65,817 44,435 39,031 (11,086 ) (7,574 ) Other Income (Expense) not included in Segment Profit 4,790 Less Equity Earnings included in Segment Profit (16,309 ) Income Before Taxes and Equity Earnings 163,235 Capital Expenditures 83,513 58,481 199,602 3,108 — 148 15,785 360,637 As of December 31, 2014 Property and Equipment Historical cost 1,060,986 491,079 453,862 47,256 3,342 271 30,161 2,086,957 Accumulated depreciation (500,007 ) (159,532 ) (213,072 ) (15,488 ) (3,002 ) (247 ) (10,936 ) (902,284 ) 560,979 331,547 240,790 31,768 340 24 19,225 1,184,673 Construction in progress 87,935 27,415 201,554 718 — 234 144 318,000 648,914 358,962 442,344 32,486 340 258 19,369 1,502,673 Investments, at Equity, and Advances to 50% or Less Owned Companies 115,436 103,688 222,420 — 524 42,089 — 484,157 Inventories 5,570 2,536 1,030 11,170 — 2,477 — 22,783 Goodwill 13,367 2,573 1,852 — 44,967 — — 62,759 Intangible Assets 1,917 6,483 292 — 24,035 — — 32,727 Other current and long-term assets, excluding cash and near cash assets (3) 128,499 99,335 23,910 11,538 26,131 45,547 7,670 342,630 Segment Assets 913,703 573,577 691,848 55,194 95,997 90,371 Cash and near cash assets (3) 786,644 Total Assets 3,234,373 ______________________ (1) Operating revenues includes $224.4 million of tangible product sales and operating expenses includes $175.8 million of costs of goods sold. (2) Inventories include raw materials of $2.2 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. During the years ended December 31, 2016 , 2015 and 2014 , the Company did not earn revenues that were greater than or equal to 10% of total revenues from a single customer. For the years ended December 31, 2016 , 2015 and 2014 , approximately 29% , 29% and 30% , respectively, of the Company’s operating revenues were derived from its foreign operations. The Company’s foreign revenues are primarily derived from its Offshore Marine Services fleet and certain of its Inland River and Shipping Services fleets. These assets are highly mobile and regularly and routinely move between countries within a geographical region of the world. In addition, these assets may be redeployed among the geographical regions as changes in market conditions dictate. Because of this asset mobility, revenues and long-lived assets, primarily property and equipment, in any one country are not considered material. The following represents the Company’s revenues attributed by geographical region in which services are provided to customers for the years ended December 31 (in thousands): 2016 2015 2014 Operating Revenues: United States $ 590,310 $ 751,548 $ 925,750 Africa, primarily West Africa 37,764 57,268 70,743 Europe, primarily North Sea 82,730 104,042 112,644 Middle East and Asia 54,950 65,045 69,598 Brazil, Mexico, Central and South America 64,837 76,404 140,460 Other 394 429 199 $ 830,985 $ 1,054,736 $ 1,319,394 The Company’s long-lived assets are primarily its property and equipment that are employed in various geographical regions of the world. The following represents the Company’s property and equipment based upon the assets’ physical location as of December 31 (in thousands): 2016 2015 2014 Property and Equipment: United States $ 1,185,917 $ 1,181,586 $ 1,120,765 Africa, primarily West Africa 75,772 73,406 82,495 Europe, primarily North Sea 83,767 72,544 75,382 Middle East and Asia 99,974 129,476 84,598 Brazil, Mexico, Central and South America 110,238 126,613 139,433 $ 1,555,668 $ 1,583,625 $ 1,502,673

Supplemental Information For St

Supplemental Information For Statements Of Cash Flows	12 Months Ended
	Dec. 31, 2016
Supplemental Cash Flow Information [Abstract]
Supplemental Information For Statements Of Cash Flows	18. SUPPLEMENTAL INFORMATION FOR STATEMENTS OF CASH FLOWS Supplemental information for the years ended December 31 was as follows (in thousands): 2016 2015 2014 Income taxes paid $ 11,933 $ 23,791 $ 52,348 Income taxes refunded 3,933 4,550 2,055 Interest paid, excluding capitalized interest 26,662 23,957 24,719 Schedule of Non-Cash Investing and Financing Activities: Company financed sale of equipment and real property 7,950 1,768 45,305 Reclassification of Dorian to marketable securities — 102,509 — Services received to settle notes receivable — 2,500 — Equipment received to settle notes receivable 14,400 — — Non-cash proceeds on the sale of property and equipment 2,000 — —

Quarterly Financial Information

Quarterly Financial Information	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Data [Abstract]
Quarterly Financial Information	19. QUARTERLY FINANCIAL INFORMATION (UNAUDITED) Selected financial information for interim quarterly periods is presented below (in thousands, except share data). Earnings per common share of SEACOR Holdings Inc. are computed independently for each of the quarters presented and the sum of the quarterly earnings per share may not necessarily equal the total for the year. Three Months Ended Dec. 31, Sept. 30, June 30, March 31, 2016 Operating Revenues $ 213,036 $ 206,983 $ 197,038 $ 213,928 Operating Loss (99,364 ) (33,016 ) (30,151 ) (10,016 ) Net Loss (90,289 ) (34,026 ) (50,933 ) (20,524 ) Net Loss attributable to SEACOR Holdings Inc. (93,749 ) (39,803 ) (55,159 ) (27,186 ) Basic Loss Per Common Share of SEACOR Holdings Inc. $ (5.52 ) $ (2.35 ) $ (3.26 ) $ (1.62 ) Diluted Loss Per Common Share of SEACOR Holdings Inc. $ (5.52 ) $ (2.35 ) $ (3.26 ) $ (1.62 ) 2015 Operating Revenues $ 250,631 $ 261,852 $ 281,609 $ 260,644 Operating Income (Loss) (928 ) 28,221 7,499 (13,667 ) Net Income (Loss) (49,853 ) 16,405 (8,501 ) (17,901 ) Net Income (Loss) attributable to SEACOR Holdings Inc. (56,865 ) 6,965 687 (19,569 ) Basic Earnings (Loss) Per Common Share of SEACOR Holdings Inc. $ (3.36 ) $ 0.40 $ 0.04 $ (1.10 ) Diluted Earnings (Loss) Per Common Share of SEACOR Holdings Inc. $ (3.36 ) $ 0.40 $ 0.04 $ (1.10 )

Valuation And Qualifying Accoun

Valuation And Qualifying Accounts	12 Months Ended
	Dec. 31, 2016
Valuation and Qualifying Accounts [Abstract]
Valuation And Qualifying Accounts	SEACOR HOLDINGS INC. SCHEDULE II – VALUATION AND QUALIFYING ACCOUNTS For the Years Ended December 31, 2016 , 2015 and 2014 (in thousands) Description Balance Beginning of Year Charges (Credits) to Cost and Expenses Deductions (1) Other (2) Balance End of Year Year Ended December 31, 2016 Allowance for doubtful accounts (deducted from trade and notes receivable) $ 2,483 $ 7,054 $ (1,190 ) $ — $ 8,347 Inventory allowance (deducted from inventory) $ 670 $ (662 ) $ — $ — $ 8 Year Ended December 31, 2015 Allowance for doubtful accounts (deducted from trade and notes receivable) $ 3,162 $ 842 $ (997 ) $ (524 ) $ 2,483 Inventory allowance (deducted from inventory) $ — $ 670 $ — $ — $ 670 Year Ended December 31, 2014 Allowance for doubtful accounts (deducted from trade and notes receivable) $ 1,162 $ 2,618 $ (1,279 ) $ 661 $ 3,162 Inventory allowance (deducted from inventory) $ 26 $ (26 ) $ — $ — $ — ______________________ (1) Trade receivable amounts deemed uncollectible that were removed from accounts receivable and allowance for doubtful accounts. (2) Other consists of balances from the consolidation or deconsolidation of certain Company subsidiaries.

Nature Of Operations And Acco27

Nature Of Operations And Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Nature Of Operations and Segmentation	Nature of Operations and Segmentation. SEACOR Holdings Inc. (“SEACOR”) and its subsidiaries (collectively referred to as the “Company”) are in the business of owning, operating, investing in and marketing equipment, primarily in the offshore oil and gas, shipping and logistics industries. Accounting standards require public business enterprises to report information about each of their operating business segments that exceed certain quantitative thresholds or meet certain other reporting requirements. Operating business segments have been defined as a component of an enterprise about which separate financial information is available and is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. Certain reclassifications of prior year information have been made to conform to the current year’s reportable segment presentation (see Note 17) as a result of Witt O’Brien’s, LLC (“Witt O’Brien’s”) meeting certain quantitative thresholds in 2016. The Company has identified the following reporting segments: Offshore Marine Services. Offshore Marine Services operates a diverse fleet of support vessels primarily servicing major integrated national and international oil companies, large independent oil and gas exploration and production companies and emerging independent companies. These vessels deliver cargo and personnel to offshore installations; provide field security services; handle anchors and mooring equipment required to tether rigs to the seabed; tow rigs and assist in placing them on location and moving them between regions; and carry and launch equipment such as remote operated vehicles or “ROVs” used underwater in drilling and well installation, maintenance, inspection and repair. In addition, Offshore Marine Services' vessels provide accommodations for technicians and specialists, and provide standby safety support and emergency response services. Offshore Marine Services also operates a fleet of liftboats in the U.S. Gulf of Mexico that primarily support well intervention, work-over, decommissioning and diving operations. In non-oil and gas industry activity, Offshore Marine Services operates vessels primarily used to move personnel and supplies to offshore wind farms in Europe. Offshore Marine Services contributed 26% , 35% and 40% of consolidated operating revenues in 2016 , 2015 and 2014 , respectively. Inland River Services. Inland River Services operates domestic river transportation equipment used for moving agricultural and industrial commodities and containers on the U.S. Inland River Waterways, primarily the Mississippi River, Illinois River, Tennessee River, Ohio River and their tributaries and the Gulf Intracoastal Waterways. Internationally, Inland River Services has liquid tank barge operations on the Magdalena River in Colombia primarily transporting petroleum products and dry-cargo barge operations on the Parana-Paraguay River Waterways in Brazil, Bolivia, Paraguay, Argentina and Uruguay primarily transporting agricultural and industrial commodities. In addition to its primary barge and towboat businesses, Inland River Services also operates and invests in high-speed multi-modal terminal facilities for both dry and liquid commodities; barge fleeting locations in various areas of the U.S. Inland River Waterways; a broad range of service facilities including machine shop and the repair and drydocking of barges and towboats at strategic locations on the U.S. Inland River Waterways; and a transshipment terminal at the Port of Ibicuy, Argentina. Inland River Services contributed 20% , 22% and 19% of consolidated operating revenues in 2016 , 2015 and 2014 , respectively. Shipping Services. Shipping Services operates a diversified fleet of U.S.-flag marine transportation related assets, including its 51% controlling interest (see Note 12) in certain subsidiaries (collectively “SEA-Vista”) that operate product tankers servicing the U.S. coastwise trade of crude oil, petroleum and chemical products, and including its harbor tugs servicing vessels docking in U.S. Gulf and East Coast ports. Additional services include liner and short-sea transportation to and from ports in Florida, Puerto Rico, the Bahamas and the Western Caribbean, a terminal support and bunkering operation in St. Eustatius, a U.S.-flag articulated tug and dry bulk barge operating on the Great Lakes, a U.S.-flag offshore tug and technical ship management services for third party vessel owners. Shipping Services contributed 28% , 21% and 16% of consolidated operating revenues in 2016 , 2015 and 2014 , respectively. Illinois Corn Processing. Illinois Corn Processing, LLC (“ICP”) operates a single-site alcohol manufacturing, storage and distribution facility located in Pekin, Illinois and is a leading producer of alcohol used in the food, beverage, industrial and petrochemical end-markets. As co-products of its manufacturing process, ICP additionally produces Dried Distillers Grains with Solubles (“DDGS”) primarily used for animal feed and produces non-food grade Corn Oil primarily used for feedstock in biodiesel production. The Company owns a 70% interest in ICP (see Note 12). ICP contributed 21% , 16% and 18% of consolidated operating revenues in 2016 , 2015 and 2014 . Witt O’Brien’s. Witt O’Brien’s provides resilience solutions for key areas of critical infrastructure, including, but not limited to, government, energy, transportation, healthcare and education, in the United States and abroad. Witt O’Brien’s protects and enhances its customers’ enterprise value by strengthening their ability to prepare for, respond to and recover from natural and man-made disasters, including hurricanes, infectious disease, terrorism, cyber breaches, oil spills, shipping incidents and other disruptions. Witt O’Brien’s contributed 5% , 5% and 2% of consolidated operating revenues in 2016 , 2015 and 2014 . Other. The Company also has activities that are referred to and described under Other, which primarily include lending and leasing activities and noncontrolling investments in various other businesses, primarily industrial aviation services businesses in Asia and an agricultural commodity trading and logistics business that is primarily focused on the global origination, trading and merchandising of sugar.
Basis Of Consolidation	Basis of Consolidation. The consolidated financial statements include the accounts of SEACOR and its controlled subsidiaries. Control is generally deemed to exist if the Company has greater than 50% of the voting rights of a subsidiary. All significant intercompany accounts and transactions are eliminated in consolidation. Noncontrolling interests in consolidated subsidiaries are included in the consolidated balance sheets as a separate component of equity. The Company reports consolidated net income inclusive of both the Company’s and the noncontrolling interests’ share, as well as the amounts of consolidated net income (loss) attributable to each of the Company and the noncontrolling interests. If a subsidiary is deconsolidated upon a change in control, any retained noncontrolled equity investment in the former controlled subsidiary is measured at fair value and a gain or loss is recognized in net income (loss) based on such fair value. If a subsidiary is consolidated upon a change in control, any previous noncontrolled equity investment in the subsidiary is measured at fair value and a gain or loss is recognized based on such fair value. The Company employs the equity method of accounting for investments in 50% or less owned companies that it does not control but has the ability to exercise significant influence over the operating and financial policies of the business venture. Significant influence is generally deemed to exist if the Company has between 20% and 50% of the voting rights of a business venture but may exist when the Company’s ownership percentage is less than 20%. In certain circumstances, the Company may have an economic interest in excess of 50% but may not control and consolidate the business venture. Conversely, the Company may have an economic interest less than 50% but may control and consolidate the business venture. The Company reports its investments in and advances to these business ventures in the accompanying consolidated balance sheets as investments, at equity, and advances to 50% or less owned companies. The Company reports its share of earnings or losses from investments in 50% or less owned companies in the accompanying consolidated statements of income (loss) as equity in earnings (losses) of 50% or less owned companies, net of tax. The Company employs the cost method of accounting for investments in 50% or less owned companies it does not control or exercise significant influence. These investments in private companies are carried at cost and are adjusted only for capital distributions and other-than-temporary declines in fair value.
Use Of Estimates	Use of Estimates. The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Such estimates include those related to deferred revenues, allowance for doubtful accounts, useful lives of property and equipment, impairments, income tax provisions and certain accrued liabilities. Actual results could differ from those estimates and those differences may be material.
Revenue Recognition	Revenue Recognition. The Company recognizes revenue when it is realized or realizable and earned. Revenue is realized or realizable and earned when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price to the buyer is fixed or determinable, and collectability is reasonably assured. Revenue that does not meet these criteria is deferred until the criteria are met. Deferred revenues for the years ended December 31 were as follows (in thousands): 2016 2015 2014 Balance at beginning of year $ 6,953 $ 6,794 $ 6,592 Revenues deferred during the year — 159 202 Balance at end of year $ 6,953 $ 6,953 $ 6,794 As of December 31, 2016 , deferred revenues of $6.8 million 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. The Company’s Offshore Marine Services segment earns and recognizes revenues primarily from the time charter and bareboat charter of vessels to customers based upon daily rates of hire. Under a time charter, Offshore Marine Services provides a vessel to a customer and is responsible for all operating expenses, typically excluding fuel. Under a bareboat charter, Offshore Marine Services provides the vessel to the customer and the customer assumes responsibility for all operating expenses and risk of operation. Vessel charters may range from several days to several years. Revenues from time charters and bareboat charters are recognized as services are provided. In the U.S. Gulf of Mexico, time charter durations and rates are typically established in the context of master service agreements that govern the terms and conditions of charter. The Company’s Inland River Services segment earns and recognizes revenues primarily from the time charter and bareboat charter of equipment to customers and from voyage affreightment contracts whereby customers are charged an established rate per ton to transport cargo from point to point. Under a time charter, Inland River Services provides equipment to a customer and is responsible for all operating expenses, typically excluding fuel. Under a bareboat charter, Inland River Services provides the equipment to the customer and the customer assumes responsibility for all operating expenses and risk of operation. These charters typically range from one to six years and revenues from these charters are recognized as services are provided on a per day basis. Revenues from voyage affreightment contracts are generally recognized over the progress of the voyage while the related costs are expensed as incurred. Certain of Inland River Services’ barges are operated in barge pools with other barges owned by third parties from whom Inland River Services earns and recognizes a management fee as the services are rendered. Pursuant to the pooling agreements, operating revenues and expenses of participating barges are combined and the net results are allocated on a pro-rata basis based on the number of barge days contributed by each participant. In addition, revenues are earned from equipment chartered to third parties and from the storage and demurrage of cargoes associated with affreightment activities. In both of these cases, revenues are recognized as services are rendered. Inland River Services’ tank farm and handling facility earns revenues through rental and throughput charges. Rental revenues are recognized ratably over the rental period while throughput charges are recognized as product volume moves through the facility. The Company’s Shipping Services segment earns revenue from the time charter, bareboat charter and voyage charter of vessels, contracts of affreightment, ship assist services, transporting third party freight and ship management agreements with vessel owners. Under a time charter, Shipping Services provides a vessel to a customer and is responsible for all operating expenses, typically excluding fuel. Under a bareboat charter, Shipping Services provides the vessel to a customer and the customer assumes responsibility for all operating expenses and risk of operation. Revenues from time charters and bareboat charters are recognized as services are provided. Voyage contracts are contracts to carry cargoes on a single voyage basis regardless of time to complete. Contracts of affreightment are contracts for cargoes that are committed on a multi-voyage basis for various periods of time with minimum and maximum cargo tonnages specified over the period at a fixed or escalating rate per ton. Revenues for voyage contracts and contracts of affreightment are recognized over the progress of the voyage while the related costs are expensed as incurred. Ship assist services are provided by the Company’s harbor towing fleet to dock and undock vessels in various ports in the U.S. Gulf of Mexico and Atlantic Coast. Revenues from ship assist services are recognized as the services are performed. Revenues from transporting freight are recognized as third party freight is transported to various destinations, typically determined by a tariff based on weight and voyage length, which is usually one to eight days. Ship management agreements typically provide for technical services over a specified period of time, typically a year or more. Revenues from ship management agreements are recognized ratably over the service period. ICP earns revenues from the sale of alcohol and co-products. Revenues and related costs from these sales are recorded when title transfers to the buyer. Witt O’Brien’s earns revenues primarily from emergency response and debris management incidents, retainer and consulting services. Emergency response and debris management revenues are recognized as services are provided. Revenues from short term remediation services and longer term customer staff augmentation services for remediation and claims management are dependent on the magnitude and number of incidents. Retainer agreements with vessel and facility owners and operators generally have evergreen terms and are typically invoiced on an annual basis. Such retainer fees are generally recognized ratable over the term of the coverage period. Consulting services are performed in accordance with retainer agreements or specific contract terms. Revenues are recognized based on contractual terms, generally on a time and material basis with revenues recognized as the services are provided or on a fixed fee basis with revenues and expenses recognized upon completion of the contract or specific task.
Cash Equivalents	Cash Equivalents. The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. Cash equivalents consist of U.S treasury securities, money market instruments, time deposits and overnight investments.
Restricted Cash	Restricted Cash. Restricted cash primarily related to cash collateral for letters of credit and banking facility requ
Marketable Securities	Marketable Securities. Marketable equity securities with readily determinable fair values and debt securities are reported in the accompanying consolidated balance sheets as marketable securities. These investments are stated at fair value, as determined by their market observable prices, with both realized and unrealized gains and losses reported in the accompanying consolidated statements of income (loss) as marketable security gains (losses), net. Short sales of marketable securities are stated at fair value in the accompanying consolidated balance sheets with both realized and unrealized gains and losses reported in the accompanying consolidated statements of income (loss) as marketable security gains (losses), net. Long and short marketable security positions are primarily in energy, marine, transportation and other related businesses. Marketable securities are classified as trading securities for financial reporting purposes with gains and losses reported as operating activities in the accompanying consolidated statements of cash flows. The Company’s most significant marketable security position is its investment in 9,177,135 shares of Dorian LPG Ltd. (“Dorian”), a publicly traded company listed on the New York Stock Exchange under the symbol “LPG” (see Note 4). Dorian’s closing share price was $8.21 and $11.77 as of December 31, 2016 and 2015, respectively. The Company’s cost basis in Dorian is $13.66 per share.
Trade Receivables	Trade Receivables. Customers of Offshore Marine Services are primarily major integrated oil companies, large independent oil and gas exploration and production companies and emerging independent companies. Customers of Inland River Services are primarily major agricultural companies, major integrated oil companies, iron ore producers and industrial companies. Customers of Shipping Services are primarily multinational oil and gas companies, refining companies, oil trading companies and large industrial consumers of crude and petroleum. Customers of ICP are primarily alcohol trading companies, industrial manufacturers, major agricultural companies, major integrated oil companies, and manufacturers in the food, beverage and household products industries. Customers of the Company’s other business activities primarily include industrial companies and distributors. All customers are granted credit on a short-term basis and related credit risks are considered minimal. The Company routinely reviews its trade receivables and makes provisions for probable doubtful accounts; however, those provisions are estimates and actual results could differ from those estimates and those differences may be material. Trade receivables are deemed uncollectible and removed from accounts receivable and the allowance for doubtful accounts when collection efforts have been exhausted.
Derivative Instruments	Derivative Instruments. The Company accounts for derivatives through the use of a fair value concept whereby all of the Company’s derivative positions are stated at fair value in the accompanying consolidated balance sheets. Realized and unrealized gains and losses on derivatives not designated as hedges are reported in the accompanying consolidated statements of income (loss) as derivative losses, net. Realized and unrealized gains and losses on derivatives designated as fair value hedges are recognized as corresponding increases or decreases in the fair value of the underlying hedged item to the extent they are effective, with any ineffective portion reported in the accompanying consolidated statements of income (loss) as derivative losses, net. Realized and unrealized gains and losses on derivatives designated as cash flow hedges are reported as a component of other comprehensive income (loss) in the accompanying consolidated statements of comprehensive income (loss) to the extent they are effective and reclassified into earnings on the same line item associated with the hedged transaction and in the same period the hedged transaction affects earnings. Any ineffective portions of cash flow hedges are reported in the accompanying consolidated statements of income (loss) as derivative losses, net. Realized and unrealized gains and losses on derivatives designated as cash flow hedges that are entered into by the Company’s 50% or less owned companies are also reported as a component of the Company’s other comprehensive income (loss) in proportion to the Company’s ownership percentage, with reclassifications and ineffective portions being included in equity in earnings (losses) of 50% or less owned companies, net of tax, in the accompanying consolidated statements of income (loss).
Concentrations Of Credit Risk	Concentrations of Credit Risk. The Company is exposed to concentrations of credit risk associated with its cash and cash equivalents, construction reserve funds and derivative instruments. The Company minimizes its credit risk relating to these positions by monitoring the financial condition of the financial institutions and counterparties involved and by primarily conducting business with large, well-established financial institutions and diversifying its counterparties. The Company does not currently anticipate nonperformance of its significant counterparties. The Company is also exposed to concentrations of credit risk relating to its receivables due from customers in the industries described above. The Company does not generally require collateral or other security to support its outstanding receivables. The Company minimizes its credit risk relating to receivables by performing ongoing credit evaluations and, to date, credit losses have not been material.
Inventories	Inventories. Inventories are stated at the lower of cost (using the first-in, first-out and average cost methods) or market. Inventories consist primarily of fuel and fuel oil in the Company’s Offshore Marine Services, Shipping Services and Inland River Services segments. Inventories in ICP consist primarily of corn, high quality alcohol and fuel alcohol. The Company records write-downs, as needed, to adjust the carrying amount of inventories to the lower of cost or market. During the years ended December 31, 2016 , 2015 and 2014 , the Company recorded market write-downs of $2.7 million , $3.0 million and $0.4 million , respectively.
Property And Equipment	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 typically based upon a newly built asset being placed into service and represents the point at which it is typically not justifiable for the Company to continue to operate the asset in the same or similar manner. From time to time, the Company may acquire older assets that have already exceeded the Company’s useful life policy, in which case the Company depreciates such assets based on its best estimate of remaining useful life, typically the next survey or certification date. As of December 31, 2016 , the estimated useful life (in years) of each of the Company’s major classes of new equipment was as follows: Offshore support vessels (excluding wind farm utility) 20 Wind farm utility vessels 10 Inland river dry-cargo and deck barges 20 Inland river liquid tank barges 25 Inland river towboats and harbor boats 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”). The Company’s major classes of property and equipment as of December 31 were as follows (in thousands): Historical Cost (1) Accumulated Depreciation Net Book Value 2016 Offshore Marine Services: Anchor handling towing supply $ 228,857 $ (183,757 ) $ 45,100 Fast support 251,415 (72,599 ) 178,816 Supply 96,774 (58,028 ) 38,746 Standby safety 109,436 (88,020 ) 21,416 Specialty 45,765 (24,063 ) 21,702 Liftboats 104,356 (45,447 ) 58,909 Wind farm utility 60,671 (29,019 ) 31,652 Machinery and spares 32,921 (20,008 ) 12,913 Other (2) 28,564 (19,678 ) 8,886 958,759 (540,619 ) 418,140 Inland River Services: Dry-cargo barges 246,237 (97,602 ) 148,635 Liquid tank barges 16,114 (1,982 ) 14,132 Towboats 14,675 (1,320 ) 13,355 Harbor boats 17,338 (5,715 ) 11,623 Specialty and deck barges 12,292 (4,869 ) 7,423 Terminal and fleeting facilities 94,913 (48,981 ) 45,932 Other (2) 18,145 (6,658 ) 11,487 419,714 (167,127 ) 252,587 Shipping Services: Product tankers - U.S.-flag 546,019 (189,536 ) 356,483 Harbor and offshore tugs - U.S.-flag 72,877 (34,606 ) 38,271 Harbor tugs - Foreign-flag 29,689 (9,480 ) 20,209 Ocean liquid tank barges - U.S.-flag 39,238 (11,604 ) 27,634 Short-sea container\RORO - Foreign-flag 20,954 (6,774 ) 14,180 Other (2) 18,825 (6,004 ) 12,821 727,602 (258,004 ) 469,598 Illinois Corn Processing: Manufacturing facilities 55,028 (23,689 ) 31,339 Land 1,680 — 1,680 56,708 (23,689 ) 33,019 Witt O’Brien’s: Other (2) 1,559 (1,244 ) 315 Corporate and Eliminations: Other (2) 29,681 (18,184 ) 11,497 $ 2,194,023 $ (1,008,867 ) $ 1,185,156 ______________________ (1) Includes property and equipment acquired in business acquisitions at acquisition date fair value, and net of the impact of recognized impairment charges. (2) Includes land and buildings, leasehold improvements, fixed-wing aircraft, vehicles and other property and equipment. Historical Cost (1) Accumulated Depreciation Net Book Value 2015 Offshore Marine Services: Anchor handling towing supply $ 301,707 $ (168,534 ) $ 133,173 Fast support 222,720 (61,515 ) 161,205 Supply 139,315 (80,862 ) 58,453 Standby Safety 141,864 (113,136 ) 28,728 Specialty 46,522 (21,224 ) 25,298 Liftboats 122,764 (36,154 ) 86,610 Wind farm utility 66,950 (26,773 ) 40,177 Machinery and spares 34,116 (19,480 ) 14,636 Other (2) 26,661 (19,284 ) 7,377 1,102,619 (546,962 ) 555,657 Inland River Services: Dry-cargo barges 226,916 (86,068 ) 140,848 Liquid tank barges 61,175 (14,638 ) 46,537 Towboats 67,265 (15,670 ) 51,595 Harbor boats 10,206 (5,136 ) 5,070 Specialty and deck barges 12,293 (3,992 ) 8,301 Terminal and fleeting facilities 90,379 (40,890 ) 49,489 Other (2) 16,910 (4,877 ) 12,033 485,144 (171,271 ) 313,873 Shipping Services: Product tankers - U.S.-flag 271,141 (168,838 ) 102,303 Harbor and offshore tugs - U.S.-flag 72,073 (37,418 ) 34,655 Harbor tugs - Foreign-flag 29,689 (8,291 ) 21,398 Ocean liquid tank barges - U.S.-flag 39,238 (10,175 ) 29,063 Short-sea container\RORO - Foreign-flag 20,954 (5,369 ) 15,585 Other (2) 21,049 (8,985 ) 12,064 454,144 (239,076 ) 215,068 Illinois Corn Processing: Manufacturing facilities 45,576 (19,390 ) 26,186 Land 1,680 — 1,680 47,256 (19,390 ) 27,866 Witt O’Brien’s: Other (2) 3,338 (2,834 ) 504 Corporate and Eliminations: Other (2) 30,700 (14,648 ) 16,052 $ 2,123,201 $ (994,181 ) $ 1,129,020 ______________________ (1) Includes property and equipment acquired in business acquisitions at acquisition date fair value, and net of the impact of recognized impairment charges. (2) Includes land and buildings, leasehold improvements, fixed-wing aircraft, vehicles and other property and equipment. Depreciation expense totaled $122.5 million , $122.9 million and $127.6 million in 2016 , 2015 and 2014 , respectively. 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. Capitalized interest totaled $18.5 million , $18.5 million and $17.0 million in 2016 , 2015 and 2014 , respectively.
Intangible Assets	Intangible Assets. The Company’s intangible assets primarily arose from business acquisitions (see Note 2) and consist of non-compete agreements, trademarks and tradenames, customer relationships, software and technology, and acquired contractual rights. These intangible assets are amortized over their estimated useful lives ranging from two to ten years. During the years ended December 31, 2016 , 2015 , and 2014 , the Company recognized amortization expense of $2.5 million , $3.1 million and $4.3 million , respectively. The Company’s intangible assets by type were as follows (in thousands): Trademark/ Tradenames Customer Relationships Software/ Technology Acquired Contractual Rights Total Gross Carrying Value Year Ended December 31, 2014 $ 10,681 $ 48,570 $ 1,652 $ 2,985 $ 63,888 Purchase price adjustments to acquired intangible assets (1,024 ) (2,133 ) — — (3,157 ) Foreign currency translation — — — (78 ) (78 ) Fully amortized intangible assets (4,737 ) (22,700 ) — — (27,437 ) Year Ended December 31, 2015 4,920 23,737 1,652 2,907 33,216 Acquired intangible assets — 1,598 — 5,500 7,098 Foreign currency translation — — — 9 9 Impairment of intangible assets (1,596 ) (8,128 ) (1,220 ) — (10,944 ) Fully amortized intangible assets — — (432 ) — (432 ) Year Ended December 31, 2016 $ 3,324 $ 17,207 $ — $ 8,416 $ 28,947 Accumulated Amortization Year Ended December 31, 2014 $ (5,429 ) $ (24,179 ) $ (96 ) $ (1,457 ) $ (31,161 ) Amortization expense (624 ) (2,543 ) (192 ) 259 (3,100 ) Fully amortized intangible assets 4,737 22,700 — — 27,437 Year Ended December 31, 2015 (1,316 ) (4,022 ) (288 ) (1,198 ) (6,824 ) Amortization expense (332 ) (1,687 ) (144 ) (314 ) (2,477 ) Fully amortized intangible assets — — 432 — 432 Year Ended December 31, 2016 $ (1,648 ) $ (5,709 ) $ — $ (1,512 ) $ (8,869 ) Weighted average remaining contractual life, in years 5.0 9.2 0.0 8.4 8.6 Future amortization expense of intangible assets for each of the years ended December 31 is as follows (in thousands): 2017 $ 2,346 2018 2,173 2019 2,227 2020 2,227 2021 2,227 Years subsequent to 2021 8,878 $ 20,078
Impairment Of Long-Lived Assets	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. 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. If the carrying values of the assets are not recoverable, as determined by the estimated undiscounted cash flows, the estimated fair value of the assets or asset groups are compared to their current carrying values and impairment charges are recorded if the carrying value exceeds fair value. The Company performs its testing on an asset or asset group basis. Generally, fair value is determined using valuation techniques, such as expected discounted cash flows or appraisals, as appropriate. During the years ended December 31, 2016 , 2015 , and 2014 , the Company recognized impairment charges of $130.8 million , $7.1 million and $4.4 million , respectively, related to long-lived assets held for use, which is included in gains (losses) on asset dispositions and impairments, net in the accompanying consolidated statements of income (loss). As a result of continued weak conditions in the offshore oil and gas markets and the corresponding reductions in utilization and rates per day worked experienced by its fleet, the Company has identified indicators of impairment for certain of Offshore Marine Services owned vessel classes and individual offshore support vessels. When reviewing its fleet for impairment, the Company groups vessels with similar operating and marketing characteristics, including cold-stacked vessels expected to return to active service, into vessel classes. All other vessels, including vessels retired and removed from service, are evaluated for impairment on a vessel by vessel basis. During the year ended December 31, 2016 , the Company determined the carrying values of Offshore Marine Services anchor handling towing supply fleet, supply fleet, liftboat fleet, retired and removed from service vessels, and certain other individual vessels were not recoverable based on its estimate of their future undiscounted cash flows. As a result, and as described in more detail below, the Company recognized aggregate impairment charges of $119.7 million to reduce their carrying values to estimated fair value based on values established by independent appraisers and other market data such as recent sales of similar vessels. The valuation methodology applied by the appraisers was an estimated cost approach less (i) estimated economic depreciation for comparably aged and conditioned assets and (ii) estimated economic obsolescence based on market data or utilization trending of the vessels over the prior two years compared with 2014 (see Note 10 for fair value measurement determinations). If market conditions further decline from the depressed utilization and rates per day worked experienced over the last two years, fair values based on future appraisals could decline significantly. During the year ended December 31, 2016 , the Company retired and removed eight Offshore Marine Services vessels from service and recognized impairment charges of $20.7 million to reduce their carrying value to estimated fair value as described above. With respect to Offshore Marine Services vessels in active service and cold-stacked status, the Company recognized impairment charges of $62.8 million for its anchor handling towing supply fleet, $19.9 million for its liftboat fleet and $12.7 million for one specialty vessel to reduce their carrying value to estimated fair value as described above. The difference between the estimated fair values for these vessels compared with their carrying values was more pronounced given their age, short remaining useful lives and current low utilization levels. As of December 31, 2016 , Offshore Marine Services anchor handling towing supply fleet and liftboat fleet had average expected remaining lives of approximately four and six years, respectively, while the impaired specialty vessel had an expected remaining life of six years. In addition, the Company recognized other impairments of $3.6 million . Offshore Marine Services’ other vessel classes and other individual vessels in active service and cold-stacked status, for which no impairment was deemed necessary, have generally experienced a less severe decline in utilization and rates per day worked based on specific market factors. The market factors include vessels with more general utility to a broad range of customers (e.g., fast support vessels), vessels required for customers to meet regulatory mandates and operating under multiple year contracts (e.g., standby safety vessels) or vessels that service customers outside of the offshore oil and gas market (e.g., wind farm utility vessels). For these vessels, the Company determined that future undiscounted cash flows held constant at levels of utilization and rates per day worked experienced in 2016 would recover their current carrying values over their expected remaining useful lives. The Company assumed that future utilization and rates per day worked will, at a minimum, maintain levels experienced in 2016 based on the market factors discussed above. The Company’s estimates of undiscounted cash flows are highly subjective as future utilization and rates per day worked are uncertain, including the timing of an estimated market recovery in the offshore oil and gas markets and the timing and cost of reactivating cold-stacked vessels. If market conditions decline further, changes in the Company’s expectations on future cash flows may result in it recognizing additional impairment charges related to Offshore Marine Services’ long-lived assets in future periods. In October 2016, Witt O’Brien’s announced the launch of a strategic growth program to focus on core services by eliminating non-core and lower margin businesses. Witt O’Brien’s core services include providing resilience solutions for key areas of critical infrastructure, including, but not limited to, government, energy, transportation, healthcare and education, in the United States and abroad. Witt O’Brien’s protects and enhances its customers’ enterprise value by strengthening their ability to prepare for, respond to and recover from natural and man-made disasters, including hurricanes, infectious disease, terrorism, cyber breaches, oil spills, shipping incidents and other disruptions. The operations scheduled for elimination include a governmental relations unit, the Company’s European (primarily United Kingdom) operations, software products and an insurance unit. As a consequence of the restructuring, during the year ended December 31, 2016 , Witt O’Brien’s recorded impairment charges of $10.0 million to write off the carrying value of customer related intangible assets associated with the non-core service lines that were eliminated. 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 carrying value of the investment. In its evaluation, the Company considers, among other items, recent and expected financial performance and returns, impairments recorded by the investee and the capital structure of the investee. When the Company determines the estimated fair value of an investment is below carrying value and the decline is other-than-temporary, the investment is written down to its estimated fair value. Actual results may vary from the Company’s estimates due to the uncertainty regarding projected financial performance, the severity and expected duration of declines in value, and the available liquidity in the capital markets to support the continuing operations of the investee, among other factors. Although the Company believes its assumptions and estimates are reasonable, the investee’s actual performance compared with the estimates could produce different results and lead to additional impairment charges in future periods. During the years ended December 31, 2016 , 2015 and 2014 , the Company recognized impairment charges of $14.7 million , $21.5 million and $3.3 million , respectively, related to its 50% or less owned companies, which are included in equity in earnings (losses) of 50% or less owned companies, net of tax in the accompanying consolidated statements of income (loss) (see Note 4).
Goodwill	Goodwill. Goodwill is recorded when the purchase price paid for an acquisition exceeds the fair value of net identified tangible and intangible assets acquired. As of December 31, 2016, substantially all of the Company’s goodwill related to Witt O’Brien’s. The Company performs an annual impairment test of goodwill and further periodic tests to the extent indicators of impairment develop between annual impairment tests. During the year ended December 31, 2016, the Company revised its annual goodwill assessment date to October 1 to better align the assessment process with the business planning and forecasting process. The Company’s impairment review process compares the fair value of the reporting unit to its carrying value, including the goodwill, related to the reporting unit. To determine the fair value of the reporting unit, the Company may use various approaches including an asset or cost approach, market approach or income approach or any combination thereof. These approaches may require the Company to make certain estimates and assumptions including projections of future cash flows, revenues and expenses. These estimates and assumptions are reviewed each time the Company tests goodwill for impairment and are typically developed as part of the Company’s routine business planning and forecasting process. Although the Company believes its assumptions and estimates are reasonable, the Company’s actual performance against its estimates could produce different results and lead to additional impairment charges in future periods. On October 1, 2016, the Company performed its annual assessment of the carrying value of goodwill recorded in the Witt O’Brien’s reporting unit. As a result of weaker conditions for core services and the elimination of non-core service lines, the assessment concluded the carrying value of the reporting unit exceeded its fair value. Based on an evaluation of the implied fair value of goodwill compared to its carrying value, an impairment charge of $19.6 million was recorded to reduce the goodwill carrying value to fair value (see Note 10). The estimated fair value of the reporting unit was based on values established by independent valuation specialists. During the year ended December 31, 2015 , the Company recognized a $13.4 million impairment charge related to goodwill in the Company’s Offshore Marine Services’ business segment. During the year ended December 31, 2014 , the Company did not recognize any goodwill impairment charges. The Company’s goodwill impairment charges are included in gains (losses) on asset dispositions and impairments, net in the accompanying consolidated statements of income (loss).
Business Combinations	Business Combinations. The Company recognizes 100% of the fair value of assets acquired, liabilities assumed, and noncontrolling interests when the acquisition constitutes a change in control of the acquired entity. Shares issued in consideration for a business combination, contingent consideration arrangements and pre-acquisition loss and gain contingencies are all measured and recorded at their acquisition-date fair value. Subsequent changes to fair value of contingent consideration arrangements are generally reflected in earnings. Any in-process research and development assets acquired are capitalized as are certain acquisition-related restructuring costs if the criteria related to exit or disposal cost obligations are met as of the acquisition date. Acquisition-related transaction costs are expensed as incurred and any changes in income tax valuation allowances and tax uncertainty accruals are recorded as an adjustment to income tax expense. The operating results of entities acquired are included in the accompanying consolidated statements of income (loss) from the date of acquisition (see Note 2).
Deferred Financing Costs	Debt Discount and Issuance Costs. Debt discounts and costs incurred in connection with the issuance of debt are amortized over the life of the related debt using the effective interest rate method for term loans and straight line method for revolving credit facilities and is included in interest expense in the accompanying consolidated statements of income (loss).
Self-Insurance Liabilities	Self-insurance Liabilities. The Company maintains hull, liability and war risk, general liability, workers compensation and other insurance customary in the industries in which it operates. Certain excess and property insurance policies are obtained through SEACOR sponsored programs, with premiums charged to participating businesses based on management’s risk assessment or insured asset values. The marine hull and liability policies have significant annual aggregate deductibles that are accrued based on actual claims incurred and historical loss experience, respectively. The Company also maintains self-insured health benefit plans for its participating employees. Exposure to the health benefit plans are limited by maintaining stop-loss and aggregate liability coverage. To the extent that estimated self-insurance losses, including the accrual of annual aggregate deductibles, differ from actual losses realized, the Company’s insurance reserves could differ significantly and may result in either higher or lower insurance expense in future periods.
Income Taxes	Income Taxes. Deferred income tax assets and liabilities have been provided in recognition of the income tax effect attributable to the book and tax basis differences of assets and liabilities reported in the accompanying consolidated financial statements. The Company does not consider the results of its foreign operations permanently reinvested and, therefore, provides U.S. income taxes on the net earnings of its foreign subsidiaries. Deferred tax assets or liabilities are provided using the enacted tax rates expected to apply to taxable income in the periods in which they are expected to be settled or realized. Interest and penalties relating to uncertain tax positions are recognized in interest expense and administrative and general, respectively, in the accompanying consolidated statements of income (loss). The Company records a valuation allowance to reduce its deferred tax assets if it is more likely than not that some portion or all of the deferred tax assets will not be realized. In the normal course of business, the Company may be subject to challenges from tax authorities regarding the amount of taxes due. These challenges may alter the timing or amount of taxable income or deductions. As part of the calculation of income tax expense, the Company determines whether the benefits of its tax positions are at least more likely than not of being sustained based on the technical merits of the tax position. For tax positions that are more likely than not of being sustained, the Company accrues the largest amount of the tax benefit that is more likely than not of being sustained. Such accruals require management to make estimates and judgments with respect to the ultimate outcome of its tax benefits and actual results could vary materially from these estimates.
Deferred Gains	Deferred Gains – Equipment Sale-Leaseback Transactions and Financed Equipment Sales. From time to time, the Company enters into equipment sale-leaseback transactions with finance companies or provides seller financing on sales of its equipment to third parties or 50% or less owned companies. A portion of the gains realized from these transactions is not immediately recognized in income and has been recorded in the accompanying consolidated balance sheets in deferred gains and other liabilities. In sale-leaseback transactions (see Note 3), gains are deferred to the extent of the present value of future minimum lease payments and are amortized as reductions to rental expense over the applicable lease terms. In financed equipment sales (see Note 3), gains are deferred to the extent that the repayment of purchase notes is dependent on the future operations of the sold equipment and are amortized based on cash received from the buyers. Deferred gain activity related to these transactions for the years ended December 31 was as follows (in thousands): 2016 2015 2014 Balance at beginning of year $ 123,376 $ 146,534 $ 110,542 Deferred gains arising from equipment sales 9,003 5,984 71,367 Amortization of deferred gains included in operating expenses as reduction to rental expense (23,272 ) (22,521 ) (18,847 ) Amortization of deferred gains included in gains (losses) on asset dispositions and impairments, net (602 ) (4,954 ) (15,686 ) Other (1,697 ) (1,667 ) (842 ) Balance at end of year $ 106,808 $ 123,376 $ 146,534 Deferred Gains – Equipment Sales to the Company’s 50% or Less Owned Companies. A portion of the gains realized from non-financed sales of the Company’s vessels and barges to its 50% or less owned companies is not immediately recognized in income and has been recorded in the accompanying consolidated balance sheets in deferred gains and other liabilities. Effective January 1, 2009, the Company adopted new accounting rules related to the sale of its vessels and barges to its 50% or less owned companies. In most instances, these sale transactions are now considered a sale of a business in which the Company relinquishes control to its 50% or less owned companies. Subsequent to the adoption of the new accounting rules, gains are deferred only to the extent of the Company’s uncalled capital commitments and are amortized as those commitments lapse or funded amounts are returned. For transactions occurring prior to the adoption of the new accounting rules, gains were deferred and are being amortized based on the Company’s ownership interest, the Company’s uncalled capital commitments, cash received and the applicable equipment’s useful lives. Deferred gain activity related to these transactions for the years ended December 31 was as follows (in thousands): 2016 2015 2014 Balance at beginning of year $ 12,533 $ 13,377 $ 14,221 Amortization of deferred gains included in gains (losses) on asset dispositions and impairments, net (1,855 ) (844 ) (844 ) Other (1,153 ) — — Balance at end of year $ 9,525 $ 12,533 $ 13,377
Stock Based Compensation	Stock Based Compensation. Stock based compensation is amortized to compensation expense on a straight line basis over the requisite service period of the grants using the Black-Scholes valuation model. The Company does not estimate forfeitures in its expense calculations as forfeiture history has been minor. The Company presents the excess tax benefits from the exercise of stock options as a financing cash flow in the accompanying consolidated statements of cash flows.
Foreign Currency Translation And Transactions	Foreign Currency Translation. The assets, liabilities and results of operations of certain SEACOR subsidiaries are measured using their functional currency which is the currency of the primary foreign economic environment in which they operate. Upon consolidating these subsidiaries with SEACOR, their assets and liabilities are translated to U.S. dollars at currency exchange rates as of the balance sheet dates and their revenues and expenses are translated at the weighted average currency exchange rates during the applicable reporting periods. Translation adjustments resulting from the process of translating these subsidiaries’ financial statements are reported in other comprehensive loss in the accompanying consolidated statements of comprehensive income (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 Derivative Losses on Cash Flow Hedges, net Other Other Comprehensive Loss Year ended December 31, 2013 $ (927 ) $ (257 ) $ (8 ) $ (1,192 ) $ 395 $ — $ (5 ) Other comprehensive income (loss) (3,949 ) 371 20 (3,558 ) (481 ) — 8 $ (4,031 ) Income tax (expense) benefit 1,382 (130 ) (7 ) 1,245 — — — 1,245 Year ended December 31, 2014 (3,494 ) (16 ) 5 (3,505 ) (86 ) — 3 $ (2,786 ) Other comprehensive income (loss) (3,129 ) (154 ) 29 (3,254 ) (442 ) — 13 $ (3,683 ) Income tax (expense) benefit 1,095 54 (10 ) 1,139 — — — 1,139 Year ended December 31, 2015 (5,528 ) (116 ) 24 (5,620 ) (528 ) — 16 $ (2,544 ) Other comprehensive income (loss) (9,331 ) 294 (31 ) (9,068 ) (1,085 ) (17 ) (13 ) $ (10,183 ) Income tax (expense) benefit 3,266 (103 ) 11 3,174 — — — 3,174 Year ended December 31, 2016 $ (11,593 ) $ 75 $ 4 $ (11,514 ) $ (1,613 ) $ (17 ) $ 3 $ (7,009 ) Foreign Currency Transactions. Certain SEACOR subsidiaries enter into transactions denominated in currencies other than their functional currency. Gains and losses resulting from changes in currency exchange rates between the functional currency and the currency in which a transaction is denominated are included in foreign currency losses, net in the accompanying consolidated statements of income (loss) in the period in which the currency exchange rates change.
Earnings Per Share	Earnings Per Share. Basic earnings per common share of SEACOR are computed based on the weighted average number of common shares issued and outstanding during the relevant periods. Diluted earnings per common share of SEACOR are computed based on the weighted average number of common shares issued and outstanding plus the effect of potentially dilutive securities through the application of the treasury stock and if-converted methods. Dilutive securities for this purpose assumes restricted stock grants have vested, common shares have been issued pursuant to the exercise of outstanding stock options and common shares have been issued pursuant to the conversion of all outstanding convertible notes. Computations of basic and diluted earnings per common share of SEACOR for the years ended December 31 were as follows (in thousands, except share data): Net Income (Loss) Average o/s Shares Per Share 2016 Basic Weighted Average Common Shares Outstanding $ (215,897 ) 16,914,928 $ (12.76 ) Effect of Dilutive Securities: Options and Restricted Stock (1) — — Convertible Securities (2)(3)(4) — — Diluted Weighted Average Common Shares Outstanding $ (215,897 ) 16,914,928 $ (12.76 ) 2015 Basic Weighted Average Common Shares Outstanding $ (68,782 ) 17,446,137 $ (3.94 ) Effect of Dilutive Securities: Options and Restricted Stock (1) — — Convertible Securities (2)(3)(4) — — Diluted Weighted Average Common Shares Outstanding $ (68,782 ) 17,446,137 $ (3.94 ) 2014 Basic Weighted Average Common Shares Outstanding $ 100,132 19,336,280 $ 5.18 Effect of Dilutive Securities: Options and Restricted Stock (1) — 403,194 Convertible Securities 21,156 6,025,851 Diluted Weighted Average Common Shares Outstanding $ 121,288 25,765,325 $ 4.71 ______________________ (1) For the years ended December 31, 2016 , 2015 , and 2014 , diluted earnings per common share of SEACOR excluded 2,020,677 , 2,078,777 and 407,698 , respectively, of certain share awards as the effect of their inclusion in the computation would be anti-dilutive. (2) For the years ended December 31, 2016 and 2015 , diluted earnings per common share of SEACOR excluded 2,664,208 and 4,148,327 shares, respectively, issuable pursuant to the Company’s 2.5% Convertible Senior Notes (see Note 7) as the effect of their inclusion in the computation would be anti-dilutive. (3) For the years ended December 31, 2016 and 2015 diluted earnings per common share of SEACOR excluded 1,825,326 and 1,825,326 shares, respectively, issuable pursuant to the Company’s 3.0% Convertible Senior Notes (see Note 7) as the effect of their inclusion in the computation would be anti-dilutive. (4) For the years ended December 31, 2016 and 2015 , diluted earnings per common share of SEACOR excluded 2,243,500 and 190,544 shares, respectively, issuable pursuant to the Company’s 3.75% Subsidiary Convertible Senior Notes (see Note 7) 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 will adopt the new standard on January 1, 2018 and expects to use the modified retrospective approach upon adoption. The Company is in the preliminary stages of determining the impact, if any, the adoption of the new accounting standard will have on its consolidated financial position, results of operations or cash flows. Principal versus agent considerations of the new standard with respect to the Company’s vessel management services and pooling arrangements may result in a gross presentation of operating revenues and expenses compared with its current net presentation for results from managed and pooled third party equipment. 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. On March 30, 2016, the FASB issued an amendment to the accounting standards, which simplifies several aspects of the accounting for share-based payment transactions, including income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The amendment is effective for fiscal years beginning after December 15, 2016 and interim periods within those fiscal years and early adoption is permitted. The Company does expect the impact of the adoption of the new standard will have a material impact on its consolidated financial position, results of operations or cash flows. On August 26, 2016, the FASB issued an amendment to the accounting standard which amends or clarifies guidance on classification of certain transactions in the statement of cash flows, including classification of proceeds from the settlement of insurance claims, debt prepayments, debt extinguishment costs and contingent consideration payments after a business combination. This new standard is effective for the Company as of January 1, 2018 and 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. On October 24, 2016, the FASB issued a new accounting standard, which requires companies to account for the income tax effects of intercompany sales and transfers of assets other than inventory. The new standard is effective for interim and annual periods beginning after December 31, 2017 and requires a modified retrospective approach to adoption. 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. On November 17, 2016, the FASB issued an amendment to the accounting standard which requires that restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total cash amounts shown on the statement of cash flows. The new standard is effective for fiscal years beginning after December 15, 2018, and interim periods within fiscal years beginning after December 15, 2019. 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. On January 26, 2017, the FASB issued an amendment to the accounting standard which simplified wording and removes step two of the goodwill impairment test. A goodwill impairment will now be the amount by which a reporting units carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The FASB also eliminated the requirements for any reporting unit with a zero or negative carrying amount to perform a qualitative assessment and, if it fails that qualitative test, to perform step two of the goodwill test. The new standard is effective for annual or interim goodwill impairment tests in fiscal years beginning after December 15, 2020, with early adoption permitted for interim or annual goodwill impairment tests on testing dates after January 1, 2017. 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.

Nature Of Operations And Acco28

Nature Of Operations And Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Deferred Revenues Included In Other Current Liabilities	Deferred revenues for the years ended December 31 were as follows (in thousands): 2016 2015 2014 Balance at beginning of year $ 6,953 $ 6,794 $ 6,592 Revenues deferred during the year — 159 202 Balance at end of year $ 6,953 $ 6,953 $ 6,794
Schedule Of Estimated Useful Life Of Equipment	As of December 31, 2016 , the estimated useful life (in years) of each of the Company’s major classes of new equipment was as follows: Offshore support vessels (excluding wind farm utility) 20 Wind farm utility vessels 10 Inland river dry-cargo and deck barges 20 Inland river liquid tank barges 25 Inland river towboats and harbor boats 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 Additions. The Company’s capital expenditures and payments on fair value derivative hedges (see Note 9) were $358.8 million , $295.9 million and $360.6 million during the years ended December 31, 2016 , 2015 , and 2014 , respectively. Major owned equipment placed in service for the years ended December 31 were as follows: 2016 (1) 2015 2014 Offshore Support Vessels: Fast support 12 3 3 Supply 2 1 2 Specialty 1 — — Wind farm utility 2 2 2 17 6 7 Inland river dry-cargo barges 46 — 65 Inland river liquid tank barges - 10,000 barrel — 8 — Inland river specialty barges — 4 — Inland river towboats 2 9 1 Product tankers - U.S.-flag 3 — — Short-sea container\RORO - Foreign-flag — — 1 Harbor tugs - U.S.-flag 1 — — ______________________ (1) Excludes five inland river harbor boats acquired in the CCM acquisition, one offshore supply vessel acquired in the Cypress CKOR acquisition and one U.S.-flag offshore tug acquired in the SeaJon II acquisition (see Note 2). Major equipment dispositions for the years ended December 31 were as follows: 2016 2015 2014 Offshore Support Vessels: Anchor handling towing supply — — 1 Fast support — 1 7 Standby safety 4 — — Supply 5 1 4 Liftboats — — 1 Wind farm utility — — 1 9 2 14 Inland river dry-cargo barges — — 80 Inland river liquid tank barges - 10,000 barrel — 35 — Inland river liquid tank barges - 30,000 barrel 19 — — Inland river deck barges — 12 — Inland river towboats 14 4 5 Product tankers - U.S.-flag 1 — 1 Short-sea container\RORO - Foreign-flag — — 2 Harbor tugs - U.S.-flag 2 — —
Property Plant And Equipment By Major Class [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 typically based upon a newly built asset being placed into service and represents the point at which it is typically not justifiable for the Company to continue to operate the asset in the same or similar manner. From time to time, the Company may acquire older assets that have already exceeded the Company’s useful life policy, in which case the Company depreciates such assets based on its best estimate of remaining useful life, typically the next survey or certification date. As of December 31, 2016 , the estimated useful life (in years) of each of the Company’s major classes of new equipment was as follows: Offshore support vessels (excluding wind farm utility) 20 Wind farm utility vessels 10 Inland river dry-cargo and deck barges 20 Inland river liquid tank barges 25 Inland river towboats and harbor boats 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”). The Company’s major classes of property and equipment as of December 31 were as follows (in thousands): Historical Cost (1) Accumulated Depreciation Net Book Value 2016 Offshore Marine Services: Anchor handling towing supply $ 228,857 $ (183,757 ) $ 45,100 Fast support 251,415 (72,599 ) 178,816 Supply 96,774 (58,028 ) 38,746 Standby safety 109,436 (88,020 ) 21,416 Specialty 45,765 (24,063 ) 21,702 Liftboats 104,356 (45,447 ) 58,909 Wind farm utility 60,671 (29,019 ) 31,652 Machinery and spares 32,921 (20,008 ) 12,913 Other (2) 28,564 (19,678 ) 8,886 958,759 (540,619 ) 418,140 Inland River Services: Dry-cargo barges 246,237 (97,602 ) 148,635 Liquid tank barges 16,114 (1,982 ) 14,132 Towboats 14,675 (1,320 ) 13,355 Harbor boats 17,338 (5,715 ) 11,623 Specialty and deck barges 12,292 (4,869 ) 7,423 Terminal and fleeting facilities 94,913 (48,981 ) 45,932 Other (2) 18,145 (6,658 ) 11,487 419,714 (167,127 ) 252,587 Shipping Services: Product tankers - U.S.-flag 546,019 (189,536 ) 356,483 Harbor and offshore tugs - U.S.-flag 72,877 (34,606 ) 38,271 Harbor tugs - Foreign-flag 29,689 (9,480 ) 20,209 Ocean liquid tank barges - U.S.-flag 39,238 (11,604 ) 27,634 Short-sea container\RORO - Foreign-flag 20,954 (6,774 ) 14,180 Other (2) 18,825 (6,004 ) 12,821 727,602 (258,004 ) 469,598 Illinois Corn Processing: Manufacturing facilities 55,028 (23,689 ) 31,339 Land 1,680 — 1,680 56,708 (23,689 ) 33,019 Witt O’Brien’s: Other (2) 1,559 (1,244 ) 315 Corporate and Eliminations: Other (2) 29,681 (18,184 ) 11,497 $ 2,194,023 $ (1,008,867 ) $ 1,185,156 ______________________ (1) Includes property and equipment acquired in business acquisitions at acquisition date fair value, and net of the impact of recognized impairment charges. (2) Includes land and buildings, leasehold improvements, fixed-wing aircraft, vehicles and other property and equipment. Historical Cost (1) Accumulated Depreciation Net Book Value 2015 Offshore Marine Services: Anchor handling towing supply $ 301,707 $ (168,534 ) $ 133,173 Fast support 222,720 (61,515 ) 161,205 Supply 139,315 (80,862 ) 58,453 Standby Safety 141,864 (113,136 ) 28,728 Specialty 46,522 (21,224 ) 25,298 Liftboats 122,764 (36,154 ) 86,610 Wind farm utility 66,950 (26,773 ) 40,177 Machinery and spares 34,116 (19,480 ) 14,636 Other (2) 26,661 (19,284 ) 7,377 1,102,619 (546,962 ) 555,657 Inland River Services: Dry-cargo barges 226,916 (86,068 ) 140,848 Liquid tank barges 61,175 (14,638 ) 46,537 Towboats 67,265 (15,670 ) 51,595 Harbor boats 10,206 (5,136 ) 5,070 Specialty and deck barges 12,293 (3,992 ) 8,301 Terminal and fleeting facilities 90,379 (40,890 ) 49,489 Other (2) 16,910 (4,877 ) 12,033 485,144 (171,271 ) 313,873 Shipping Services: Product tankers - U.S.-flag 271,141 (168,838 ) 102,303 Harbor and offshore tugs - U.S.-flag 72,073 (37,418 ) 34,655 Harbor tugs - Foreign-flag 29,689 (8,291 ) 21,398 Ocean liquid tank barges - U.S.-flag 39,238 (10,175 ) 29,063 Short-sea container\RORO - Foreign-flag 20,954 (5,369 ) 15,585 Other (2) 21,049 (8,985 ) 12,064 454,144 (239,076 ) 215,068 Illinois Corn Processing: Manufacturing facilities 45,576 (19,390 ) 26,186 Land 1,680 — 1,680 47,256 (19,390 ) 27,866 Witt O’Brien’s: Other (2) 3,338 (2,834 ) 504 Corporate and Eliminations: Other (2) 30,700 (14,648 ) 16,052 $ 2,123,201 $ (994,181 ) $ 1,129,020 ______________________ (1) Includes property and equipment acquired in business acquisitions at acquisition date fair value, and net of the impact of recognized impairment charges. (2) Includes land and buildings, leasehold improvements, fixed-wing aircraft, vehicles and other property and equipment.
Schedule Of Intangible Assets	The Company’s intangible assets by type were as follows (in thousands): Trademark/ Tradenames Customer Relationships Software/ Technology Acquired Contractual Rights Total Gross Carrying Value Year Ended December 31, 2014 $ 10,681 $ 48,570 $ 1,652 $ 2,985 $ 63,888 Purchase price adjustments to acquired intangible assets (1,024 ) (2,133 ) — — (3,157 ) Foreign currency translation — — — (78 ) (78 ) Fully amortized intangible assets (4,737 ) (22,700 ) — — (27,437 ) Year Ended December 31, 2015 4,920 23,737 1,652 2,907 33,216 Acquired intangible assets — 1,598 — 5,500 7,098 Foreign currency translation — — — 9 9 Impairment of intangible assets (1,596 ) (8,128 ) (1,220 ) — (10,944 ) Fully amortized intangible assets — — (432 ) — (432 ) Year Ended December 31, 2016 $ 3,324 $ 17,207 $ — $ 8,416 $ 28,947 Accumulated Amortization Year Ended December 31, 2014 $ (5,429 ) $ (24,179 ) $ (96 ) $ (1,457 ) $ (31,161 ) Amortization expense (624 ) (2,543 ) (192 ) 259 (3,100 ) Fully amortized intangible assets 4,737 22,700 — — 27,437 Year Ended December 31, 2015 (1,316 ) (4,022 ) (288 ) (1,198 ) (6,824 ) Amortization expense (332 ) (1,687 ) (144 ) (314 ) (2,477 ) Fully amortized intangible assets — — 432 — 432 Year Ended December 31, 2016 $ (1,648 ) $ (5,709 ) $ — $ (1,512 ) $ (8,869 ) Weighted average remaining contractual life, in years 5.0 9.2 0.0 8.4 8.6
Schedule Of Future Amortization Expense Of Intangible Assets	Future amortization expense of intangible assets for each of the years ended December 31 is as follows (in thousands): 2017 $ 2,346 2018 2,173 2019 2,227 2020 2,227 2021 2,227 Years subsequent to 2021 8,878 $ 20,078
Schedule of Deferred Gains	Deferred gain activity related to these transactions for the years ended December 31 was as follows (in thousands): 2016 2015 2014 Balance at beginning of year $ 123,376 $ 146,534 $ 110,542 Deferred gains arising from equipment sales 9,003 5,984 71,367 Amortization of deferred gains included in operating expenses as reduction to rental expense (23,272 ) (22,521 ) (18,847 ) Amortization of deferred gains included in gains (losses) on asset dispositions and impairments, net (602 ) (4,954 ) (15,686 ) Other (1,697 ) (1,667 ) (842 ) Balance at end of year $ 106,808 $ 123,376 $ 146,534 Deferred gain activity related to these transactions for the years ended December 31 was as follows (in thousands): 2016 2015 2014 Balance at beginning of year $ 12,533 $ 13,377 $ 14,221 Amortization of deferred gains included in gains (losses) on asset dispositions and impairments, net (1,855 ) (844 ) (844 ) Other (1,153 ) — — Balance at end of year $ 9,525 $ 12,533 $ 13,377
Schedule of Accumulated Other Comprehensive Income (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 Derivative Losses on Cash Flow Hedges, net Other Other Comprehensive Loss Year ended December 31, 2013 $ (927 ) $ (257 ) $ (8 ) $ (1,192 ) $ 395 $ — $ (5 ) Other comprehensive income (loss) (3,949 ) 371 20 (3,558 ) (481 ) — 8 $ (4,031 ) Income tax (expense) benefit 1,382 (130 ) (7 ) 1,245 — — — 1,245 Year ended December 31, 2014 (3,494 ) (16 ) 5 (3,505 ) (86 ) — 3 $ (2,786 ) Other comprehensive income (loss) (3,129 ) (154 ) 29 (3,254 ) (442 ) — 13 $ (3,683 ) Income tax (expense) benefit 1,095 54 (10 ) 1,139 — — — 1,139 Year ended December 31, 2015 (5,528 ) (116 ) 24 (5,620 ) (528 ) — 16 $ (2,544 ) Other comprehensive income (loss) (9,331 ) 294 (31 ) (9,068 ) (1,085 ) (17 ) (13 ) $ (10,183 ) Income tax (expense) benefit 3,266 (103 ) 11 3,174 — — — 3,174 Year ended December 31, 2016 $ (11,593 ) $ 75 $ 4 $ (11,514 ) $ (1,613 ) $ (17 ) $ 3 $ (7,009 )
Schedule Of Earnings Per Share	Computations of basic and diluted earnings per common share of SEACOR for the years ended December 31 were as follows (in thousands, except share data): Net Income (Loss) Average o/s Shares Per Share 2016 Basic Weighted Average Common Shares Outstanding $ (215,897 ) 16,914,928 $ (12.76 ) Effect of Dilutive Securities: Options and Restricted Stock (1) — — Convertible Securities (2)(3)(4) — — Diluted Weighted Average Common Shares Outstanding $ (215,897 ) 16,914,928 $ (12.76 ) 2015 Basic Weighted Average Common Shares Outstanding $ (68,782 ) 17,446,137 $ (3.94 ) Effect of Dilutive Securities: Options and Restricted Stock (1) — — Convertible Securities (2)(3)(4) — — Diluted Weighted Average Common Shares Outstanding $ (68,782 ) 17,446,137 $ (3.94 ) 2014 Basic Weighted Average Common Shares Outstanding $ 100,132 19,336,280 $ 5.18 Effect of Dilutive Securities: Options and Restricted Stock (1) — 403,194 Convertible Securities 21,156 6,025,851 Diluted Weighted Average Common Shares Outstanding $ 121,288 25,765,325 $ 4.71 ______________________ (1) For the years ended December 31, 2016 , 2015 , and 2014 , diluted earnings per common share of SEACOR excluded 2,020,677 , 2,078,777 and 407,698 , respectively, of certain share awards as the effect of their inclusion in the computation would be anti-dilutive. (2) For the years ended December 31, 2016 and 2015 , diluted earnings per common share of SEACOR excluded 2,664,208 and 4,148,327 shares, respectively, issuable pursuant to the Company’s 2.5% Convertible Senior Notes (see Note 7) as the effect of their inclusion in the computation would be anti-dilutive. (3) For the years ended December 31, 2016 and 2015 diluted earnings per common share of SEACOR excluded 1,825,326 and 1,825,326 shares, respectively, issuable pursuant to the Company’s 3.0% Convertible Senior Notes (see Note 7) as the effect of their inclusion in the computation would be anti-dilutive. (4) For the years ended December 31, 2016 and 2015 , diluted earnings per common share of SEACOR excluded 2,243,500 and 190,544 shares, respectively, issuable pursuant to the Company’s 3.75% Subsidiary Convertible Senior Notes (see Note 7) as the effect of their inclusion in the computation would be anti-dilutive.

Business Acquisitions (Tables)

Business Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	Purchase Price Allocation. The allocation of the purchase price for the Company’s acquisitions for the years ended December 31 was as follows (in thousands): 2016 2015 2014 Restricted cash $ 275 $ — $ — Trade and other receivables 2,187 — 31,079 Other current assets 150 — 1,925 Investments, at Equity, and Advances to 50% or Less Owned Companies (3,437 ) — (49,968 ) Property and Equipment 17,132 — 519 Goodwill — 3,157 44,967 Intangible Assets 7,098 (3,157 ) 24,901 Other Assets — — 111 Accounts payable 238 — (1,709 ) Other current liabilities (13 ) — (12,274 ) Long-Term Debt (3,091 ) — (3,266 ) Deferred Income Taxes — — 91 Other Liabilities — — (1,376 ) Purchase price (1) $ 20,539 $ — $ 35,000 ______________________ (1) Purchase price is net of cash acquired totaling $0.9 million and $0.4 million in 2016 and 2014 , respectively.

Equipment Acquisitions And Disp

Equipment Acquisitions And Dispositions (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure Text Block [Abstract]
Property, Plant and Equipment Disclosure [Text Block]	3. EQUIPMENT ACQUISITIONS AND DISPOSITIONS Equipment Additions. The Company’s capital expenditures and payments on fair value derivative hedges (see Note 9) were $358.8 million , $295.9 million and $360.6 million during the years ended December 31, 2016 , 2015 , and 2014 , respectively. Major owned equipment placed in service for the years ended December 31 were as follows: 2016 (1) 2015 2014 Offshore Support Vessels: Fast support 12 3 3 Supply 2 1 2 Specialty 1 — — Wind farm utility 2 2 2 17 6 7 Inland river dry-cargo barges 46 — 65 Inland river liquid tank barges - 10,000 barrel — 8 — Inland river specialty barges — 4 — Inland river towboats 2 9 1 Product tankers - U.S.-flag 3 — — Short-sea container\RORO - Foreign-flag — — 1 Harbor tugs - U.S.-flag 1 — — ______________________ (1) Excludes five inland river harbor boats acquired in the CCM acquisition, one offshore supply vessel acquired in the Cypress CKOR acquisition and one U.S.-flag offshore tug acquired in the SeaJon II acquisition (see Note 2). Equipment Dispositions. During the year ended December 31, 2016 , the Company sold property and equipment for net proceeds of $194.4 million ( $184.4 million in cash, $8.0 million in seller financing and one U.S.-flag harbor tug valued at $2.0 million ) and gains of $14.7 million , of which $5.7 million were recognized currently and $9.0 million were deferred (see Note 1). Equipment dispositions included the sale-leaseback of one U.S.-flag product tanker for $61.0 million , with leaseback terms of 76 months. Gains of $8.2 million related to the sale-leaseback were deferred and are being amortized over their respective minimum lease periods. In addition, the Company received $0.5 million in deposits on future property and equipment sales and recognized previously deferred gains of $2.5 million . During the year ended December 31, 2015 , the Company sold property and equipment for net proceeds of $97.2 million ( $95.5 million in cash and $1.7 million in seller financing) and gains of $18.3 million , of which $12.3 million were recognized currently and $6.0 million were deferred (see Note 1). Equipment dispositions included the sale-leaseback of four inland river towboats for $35.3 million , with leaseback terms of 84 months. Gains of $4.2 million related to these sale-leasebacks were deferred and are being amortized over their respective minimum lease periods. In addition, the Company recognized previously deferred gains of $5.8 million . During the year ended December 31, 2014 , the Company sold property and equipment for net proceeds of $300.1 million ( $254.8 million in cash and $45.3 million in seller financing) and gains of $111.2 million , of which $39.8 million were recognized currently and $71.4 million were deferred (see Note 1). Equipment dispositions included the sale-leaseback of one anchor handling towing supply vessel, one fast support vessel, one liftboat, one U.S.-flag product tanker and other equipment for $141.8 million , with leaseback terms ranging from 10 months to 84 months. Gains of $52.0 million related to these sale-leasebacks were deferred and are being amortized over their respective minimum lease periods. The Company also financed the sale of two offshore support vessels, 20 dry-cargo barges and one inland river towboat to certain of its 50% or less owned companies (see Note 4) and real property and other equipment to an unrelated third party for $45.3 million in the aggregate. Gains of $19.4 million from these sales were deferred and will be recognized as payments are received under the terms of the financing. In addition, the Company recognized previously deferred gains of $16.5 million . Major equipment dispositions for the years ended December 31 were as follows: 2016 2015 2014 Offshore Support Vessels: Anchor handling towing supply — — 1 Fast support — 1 7 Standby safety 4 — — Supply 5 1 4 Liftboats — — 1 Wind farm utility — — 1 9 2 14 Inland river dry-cargo barges — — 80 Inland river liquid tank barges - 10,000 barrel — 35 — Inland river liquid tank barges - 30,000 barrel 19 — — Inland river deck barges — 12 — Inland river towboats 14 4 5 Product tankers - U.S.-flag 1 — 1 Short-sea container\RORO - Foreign-flag — — 2 Harbor tugs - U.S.-flag 2 — —
Property, Plant and Equipment [Table Text Block]	As of December 31, 2016 , the estimated useful life (in years) of each of the Company’s major classes of new equipment was as follows: Offshore support vessels (excluding wind farm utility) 20 Wind farm utility vessels 10 Inland river dry-cargo and deck barges 20 Inland river liquid tank barges 25 Inland river towboats and harbor boats 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 Additions. The Company’s capital expenditures and payments on fair value derivative hedges (see Note 9) were $358.8 million , $295.9 million and $360.6 million during the years ended December 31, 2016 , 2015 , and 2014 , respectively. Major owned equipment placed in service for the years ended December 31 were as follows: 2016 (1) 2015 2014 Offshore Support Vessels: Fast support 12 3 3 Supply 2 1 2 Specialty 1 — — Wind farm utility 2 2 2 17 6 7 Inland river dry-cargo barges 46 — 65 Inland river liquid tank barges - 10,000 barrel — 8 — Inland river specialty barges — 4 — Inland river towboats 2 9 1 Product tankers - U.S.-flag 3 — — Short-sea container\RORO - Foreign-flag — — 1 Harbor tugs - U.S.-flag 1 — — ______________________ (1) Excludes five inland river harbor boats acquired in the CCM acquisition, one offshore supply vessel acquired in the Cypress CKOR acquisition and one U.S.-flag offshore tug acquired in the SeaJon II acquisition (see Note 2). Major equipment dispositions for the years ended December 31 were as follows: 2016 2015 2014 Offshore Support Vessels: Anchor handling towing supply — — 1 Fast support — 1 7 Standby safety 4 — — Supply 5 1 4 Liftboats — — 1 Wind farm utility — — 1 9 2 14 Inland river dry-cargo barges — — 80 Inland river liquid tank barges - 10,000 barrel — 35 — Inland river liquid tank barges - 30,000 barrel 19 — — Inland river deck barges — 12 — Inland river towboats 14 4 5 Product tankers - U.S.-flag 1 — 1 Short-sea container\RORO - Foreign-flag — — 2 Harbor tugs - U.S.-flag 2 — —

Investments, At Equity, And A31

Investments, At Equity, And Advances To 50% Or Less Owned Companies (Tables)	12 Months Ended
	Dec. 31, 2016
Equity Method Investment, Summarized Financial Information [Abstract]
Summarized Financial Information For The Company's Investments, At Equity	Summarized financial information for Dorian as of and for the years ended December 31 was as follows (in thousands): 2015 (1) 2014 Current assets $ 98,254 $ 198,058 Noncurrent assets 1,724,758 812,164 Current liabilities 88,021 20,662 Noncurrent liabilities 759,636 125,716 2015 (1) 2014 Operating Revenues $ 239,206 $ 78,666 Operating Income 126,820 20,494 Net Income 118,356 15,122 ______________________ (1) Financial information provided is as of and for the year ended December 31, 2015 as it was not practical to obtain financial information through period ended December 21, 2015 without undue difficulty or cost. Investments, at equity, and advances to 50% or less owned companies as of December 31 were as follows (in thousands): Ownership 2016 2015 Offshore Marine Services: MexMar 49.0% $ 63,404 $ 50,163 Falcon Global 50.0% 18,539 17,951 Dynamic Offshore 19.0% 15,871 14,172 Sea-Cat Crewzer II 50.0% 11,246 11,339 OSV Partners 30.4% 9,245 11,374 Nautical Power 50.0% 6,413 6,412 Sea-Cat Crewzer 50.0% 4,088 2,701 Other 20.0% – 50.0% 9,505 15,898 138,311 130,010 Inland River Services: SCFCo 50.0% 46,028 57,437 Bunge-SCF Grain 50.0% 16,176 16,695 SCF Bunge Marine 50.0% 4,233 4,544 Other 50.0% 2,744 2,687 69,181 81,363 Shipping Services: Trailer Bridge (1) 55.3% 43,050 41,710 SEA-Access 50.0% — 8,414 SeaJon 50.0% 8,570 7,987 SeaJon II 50.0% — 6,388 51,620 64,499 Other: Hawker Pacific 34.2% 20,418 20,964 VA&E 41.3% 11,133 13,954 Avion 39.1% 14,783 11,994 Cleancor 50.0% 5,373 5,613 Other 34.0% – 50.0 % 2,953 2,706 54,660 55,231 $ 313,772 $ 331,103 ______________________ (1) The Company’s ownership percentage represents its economic interest in the joint venture. Combined Condensed Financial Information. Summarized financial information for the Company’s investments, at equity, excluding Dorian, as of and for the years ended December 31 was as follows (in thousands): 2016 2015 Current assets $ 745,872 $ 603,446 Noncurrent assets 1,009,317 1,066,610 Current liabilities 622,530 401,987 Noncurrent liabilities 458,922 674,896 2016 2015 2014 Operating Revenues $ 1,359,370 $ 1,281,708 $ 1,175,872 Costs and Expenses: Operating and administrative 1,204,496 1,085,518 1,021,730 Depreciation 80,784 94,105 61,233 1,285,280 1,179,623 1,082,963 Gains (Losses) on Asset Dispositions and Impairments, Net (27,900 ) (2,174 ) 368 Operating Income $ 46,190 $ 99,911 $ 93,277 Net Income (Loss) $ (34,569 ) $ 18,835 $ 29,296

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2016
Long-term Debt, Unclassified [Abstract]
Schedule Of Company's Borrowings	The Company’s borrowings as of December 31 were as follows (in thousands): 2016 2015 3.0% Convertible Senior Notes (1) $ 230,000 $ 230,000 2.5% Convertible Senior Notes (2) 157,128 284,500 7.375% Senior Notes (3) 160,699 195,941 3.75% Subsidiary Convertible Senior Notes (4) 175,000 175,000 SEA-Vista Credit Facility (5) 279,245 210,025 Other (6) 82,742 54,287 1,084,814 1,149,753 Portion due within one year, net of related debt discount and issuance costs (183,602 ) (35,531 ) Debt discount included in long-term debt (39,537 ) (62,914 ) Debt issuance costs included in long-term debt (12,904 ) (16,449 ) $ 848,771 $ 1,034,859 ______________________ (1) Excludes unamortized discount and unamortized issue costs of $29.8 million and $3.0 million , respectively, as of December 31, 2016 and $36.2 million and $3.7 million , respectively, as of December 31, 2015 . (2) Excludes unamortized discount and unamortized issue costs of $4.8 million and $0.8 million , respectively, as of December 31, 2016 and $17.3 million and $2.8 million , respectively, as of December 31, 2015 . (3) Excludes unamortized discount and unamortized issue costs of $0.4 million and $0.5 million , respectively, as of December 31, 2016 and $0.6 million and $0.9 million , respectively, as of December 31, 2015 . (4) Excludes unamortized discount and unamortized issue costs of $4.1 million and $3.1 million , respectively, as of December 31, 2016 and $8.2 million and $6.2 million , respectively, as of December 31, 2015 . (5) Excludes unamortized issue costs of $2.0 million and $2.7 million as of December 31, 2016 and December 31, 2015 , respectively. (6) Excludes unamortized discount and unamortized issue costs of $0.5 million and $3.5 million , respectively, as of December 31, 2016 and unamortized discount and unamortized issue costs of $0.6 million and $0.2 million , respectively, as of December 31, 2015 .
Schedule Of Long-Term Debt Maturities	The Company’s contractual long-term debt maturities for the years ended December 31 are as follows (in thousands): 2017 (1) $ 189,164 2018 21,766 2019 183,212 2020 238,846 2021 25,800 Years subsequent to 2021 426,026 $ 1,084,814 ______________________ (1) Includes the aggregate principal amount outstanding of the Company’s 2.5% Convertible Senior Notes with a contractual maturity date of December 15, 2027 as the holders may require the Company to repurchase the notes on December 19, 2017.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Schedule Of Income Before Income Tax, Domestic and Foreign	Income (loss) before income tax expense (benefit) and equity in earnings (losses) of 50% or less owned companies derived from U.S. and foreign companies for the years ended December 31 were as follows (in thousands): 2016 2015 2014 United States $ (242,375 ) $ (25,441 ) $ 160,782 Foreign (29,200 ) (2,896 ) (5,409 ) Eliminations and other 9,327 (2,461 ) 7,862 $ (262,248 ) $ (30,798 ) $ 163,235
Components Of Income Tax Expense (Benefit)	The Company files a consolidated U.S. federal tax return. The components of income tax expense (benefit) for the years ended December 31 were as follows (in thousands): 2016 2015 2014 Current: State $ 5,339 $ 3,155 $ 5,526 Federal (9,260 ) 17,442 56,675 Foreign 5,815 5,971 10,060 1,894 26,568 72,261 Deferred: State (2,568 ) (1,875 ) 196 Federal (93,246 ) (35,539 ) (17,222 ) Foreign 90 (516 ) (38 ) (95,724 ) (37,930 ) (17,064 ) $ (93,830 ) $ (11,362 ) $ 55,197
Components Of Effective Income Tax Rate Reconciliation	The following table reconciles the difference between the statutory federal income tax rate for the Company and the effective income tax rate for the years ended December 31 : 2016 2015 2014 Statutory rate (35.0 )% (35.0 )% 35.0 % Non-deductible expenses 0.1 % 1.7 % 0.5 % Noncontrolling interests (2.6 )% (8.1 )% (5.3 )% Losses of foreign subsidiaries not benefited 1.3 % 6.2 % 1.2 % State taxes 0.3 % 0.6 % 2.3 % Other 0.1 % (2.3 )% 0.1 % (35.8 )% (36.9 )% 33.8 %
Components Of The Net Deferred Income Tax Liabilities	The components of the net deferred income tax liabilities for the years ended December 31 were as follows (in thousands): 2016 2015 Deferred tax liabilities: Property and equipment $ 257,337 $ 302,529 Long-term debt 46,380 56,110 Unremitted earnings of foreign subsidiaries 24,263 34,977 Investments in 50% or less owned companies 16,549 14,461 Intangible assets 1,908 6,150 Deductible goodwill — 4,124 Other 194 990 Total deferred tax liabilities 346,631 419,341 Deferred tax assets: Share award plans 11,078 11,827 Losses on marketable securities 20,746 8,863 Deductible goodwill 1,611 — Debt and equity issuance costs 7,638 3,029 Other 20,557 8,991 Total deferred tax assets 61,630 32,710 Valuation allowance (3,600 ) (3,357 ) Net deferred tax assets 58,030 29,353 Net deferred tax liabilities $ 288,601 $ 389,988

Derivative Instruments And He34

Derivative Instruments And Hedging Strategies (Tables)	12 Months Ended
	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Values Of Derivative Instruments	Derivative instruments are classified as either assets or liabilities based on their individual fair values. The fair values of the Company’s derivative instruments as of December 31 were as follows (in thousands): 2016 2015 Derivative Asset (1) Derivative Liability (2) Derivative Asset (1) Derivative Liability (2) Derivatives designated as hedging instruments: Forward currency exchange contracts (fair value hedges) $ — $ 316 $ — $ — Interest rate swap agreements (cash flow hedges) — 73 — — — 389 — — Derivatives not designated as hedging instruments: Exchange option liability on subsidiary convertible senior notes — 19,436 — 5,611 Options on equities and equity indices — — — 4,005 Forward currency exchange, option and future contracts 195 194 — 57 Interest rate swap agreements — — — 242 Exchange traded commodity swap, option and future contracts: 1,042 598 469 981 1,237 20,228 469 10,896 $ 1,237 $ 20,617 $ 469 $ 10,896 ______________________ (1) Included in other receivables in the accompanying consolidated balance sheets. (2) Included in other current liabilities in the accompanying consolidated balance sheets, except for the exchange option liability on subsidiary convertible senior notes.
Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments	The Company recognized gains (losses) on derivative instruments not designated as hedging instruments for the years ended December 31 as follows (in thousands): Derivative gains (losses), net 2016 2015 2014 Exchange option liability on subsidiary convertible senior notes $ (13,826 ) $ 2,900 $ — Options on equities and equity indices 3,095 (3,200 ) 38 Forward currency exchange, option and future contracts (378 ) (519 ) (183 ) Interest rate swap agreements (18 ) (18 ) (176 ) Commodity swap, option and future contracts: Exchange traded 902 (2,744 ) (4,250 ) Non-exchange traded — 1,485 669 $ (10,225 ) $ (2,096 ) $ (3,902 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Financial Assets And Liabilities Measured At Fair Value On Recurring Basis	The Company’s financial assets and liabilities as of December 31 that are measured at fair value on a recurring basis were as follows (in thousands): Level 1 Level 2 Level 3 2016 ASSETS Marketable securities (1) $ 116,276 $ — $ — Derivative instruments (included in other receivables) 1,042 195 — Construction reserve funds 153,962 — — LIABILITIES Short sales of marketable securities 1,274 — — Derivative instruments (included in other current liabilities) 598 583 — Exchange option liability on subsidiary convertible senior notes — — 19,436 2015 ASSETS Marketable securities (1) $ 138,200 $ — $ — Derivative instruments (included in other receivables) 469 — — Construction reserve funds 255,408 — — LIABILITIES Short sales of marketable securities 4,827 — — Derivative instruments (included in other current liabilities) 4,986 299 — Exchange option liability on subsidiary convertible senior notes — — 5,611 ______________________ (1) Marketable security gains (losses), net include losses of $34.0 million , losses of $1.4 million and gains of $0.3 million for the years ended December 31, 2016 , 2015 and 2014 , respectively, related to marketable security positions held by the Company as of December 31, 2016 . Marketable security gains (losses), net include gains of $1.5 million and $0.3 million for the years ended December 31, 2015 and 2014 , respectively, related to marketable security positions held by the Company as of December 31, 2015 .
Estimated Fair Value Of Other Financial Assets And Liabilities	The estimated fair value of the Company’s other financial assets and liabilities as of December 31 were as follows (in thousands): Carrying Amount Level 1 Level 2 Level 3 2016 ASSETS Cash, cash equivalents and restricted cash $ 403,355 $ 403,355 $ — $ — Investments, at cost, in 50% or less owned companies (included in other assets) 4,432 see below Notes receivable from third parties (included in other receivables and other assets) 12,342 see below LIABILITIES Long-term debt, including current portion (1) 1,032,373 — 1,062,160 — 2015 ASSETS Cash and cash equivalents $ 530,009 $ 530,009 $ — $ — 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) 24,587 see below LIABILITIES Long-term debt, including current portion (1) 1,070,390 — 1,043,576 — ______________________ (1) The estimated fair value includes the embedded conversion options on the Company’s 2.5% and 3.0% Convertible Senior Notes.
Non-Financial Assets And Liabilities Measured At Fair Value	The Company’s non-financial assets that were measured at fair value during the years ended December 31 were as follows (in thousands): Level 1 Level 2 Level 3 2016 ASSETS Property and equipment: Anchor handling towing supply $ — $ 2,600 $ 42,500 Liftboats — — 62,830 Specialty — 4,000 — Other — 3,003 1,800 Goodwill — — 28,506 Investments, at cost, in 50% or less owned companies (included in other assets) — 3,600 — Investment, at equity, and advances in 50% or less owned companies — 3,438 48,150 Notes receivable from third parties (included in other assets) — — 11,900 2015 ASSETS Property and equipment $ — $ 200 $ — Investment, at equity, and advances in 50% or less owned companies 102,509 6,802 39,201 Property and equipment. During the year ended December 31, 2016 , the Company recognized impairment charges of $120.8 million associated with certain Offshore Marine Services’ offshore support vessels and certain Inland River Services’ equipment currently under construction (see Note 1). The Level 2 fair values were determined based on the contracted sales prices of the property and equipment, sales prices of similar property and equipment or scrap value, as applicable. The Level 3 fair values were determined based on third-party valuations using significant inputs that are unobservable in the market. Due to limited market transactions, the primary valuation methodology applied by the appraisers was an estimated cost approach less estimated economic depreciation for comparably aged and conditioned assets less estimated economic obsolescence based on market data or utilization and rates per day worked trending of the vessel class over the prior two years compared with 2014. The significant unobservable inputs used in the fair value measurement for the anchor handling towing supply fleet were the estimated construction costs for similar new equipment of $364.0 million , estimated economic fleet depreciation of 55% based on average expected remaining useful life and estimated economic obsolescence of 74% . The significant unobservable inputs used in the fair value measurement for the liftboat fleet were the estimated construction costs for similar new equipment of $279.0 million , estimated economic fleet depreciation of 42% based on average expected remaining useful life and estimated average economic obsolescence of 61% . During the year ended December 31, 2015 , the Company recognized impairment charges of $6.6 million related to the suspended construction of two offshore support vessels. The fair value of the construction in progress was determined based on the scrap value of the hulls. Goodwill. During the year ended December 31, 2016 , the Company recognized goodwill impairment charges of $19.6 million following a restructuring of Witt O’Brien’s (see Note 1). The fair value of Witt O’Brien’s was based on an appraisal performed in conjunction with the Company’s annual impairment test of goodwill on October 1, 2016 using significant inputs that are unobservable in the market and therefore are considered a Level 3 fair value measurement. The significant unobservable inputs used in the fair value measurement were industry transactions, cash flow projections and discount rates. The appraisal utilized both a market approach based on implied revenues and earnings multiples from industry transactions occurring in the prior five years and an income approach based on a discounted cash flow analysis of projected operating results, investment needs and capital expenditures, to establish value. The income approach was weighted more heavily based on the recent strategic growth program and management’s projected financial data. Under the income approach, fair value was determined by discounting the estimated future cash flows over a discrete period using an estimated weighted average cost of capital. The assumptions and estimates underlying the annual impairment assessment, such as the timing and extent of natural and man-made disasters, associated revenue and operating expenses are highly judgmental. Investments, at cost, in 50% or less owned companies. During the year ended December 31, 2016 , the Company identified indicators of impairment in a Shipping Services cost investment in a foreign container shipping company and an Other cost investment in a foreign industrial aircraft company and, as a consequence, recognized impairment charges of $11.6 million for an other-than-temporary decline in fair value. The Level 2 fair value of the Shipping Services cost investment was based on the value of the common stock issued in a recent offering. The Other cost investment was determined to have an immaterial value. Investments, at equity, and advances in 50% or less owned companies. During the year ended December 31, 2016 , the Company marked its investments to fair value in certain of its 50% or less owned companies as follows: • the Company identified indicators of impairment in one of Offshore Marine Services’ other equity method investments as a result of continuing weak market conditions and, as a consequence, recognized a $0.5 million impairment charge, net of tax, for an other-than-temporary decline in fair value. The investment was determined to have no value and the Company has suspended equity method accounting (see Note 4); • the Company identified indicators of impairment in its investment in Falcon Global as a result of continuing weak market conditions and, as a consequence, recognized a $6.4 million impairment charge, net of tax, for an other-than-temporary decline in fair value. Falcon Global’s primary assets consist of two liftboats in the final stages of construction and the estimated fair value of the liftboats was the primary input used by the Company in determining the fair value of its investment (see Note 4) and resulting impairment charge. The fair value of the liftboats was determined based on a third-party valuation using significant inputs that are unobservable in the market and therefore are considered a Level 3 fair value measurement. Due to limited market transactions, the primary valuation methodology applied by the appraisers was an estimated cost approach less economic obsolescence based on utilization and rates per day worked trending over the prior year in the Middle East region where the vessels are intended to operate. The significant unobservable inputs used in the fair value measurement were the estimated construction costs of similar new equipment and economic obsolescence of 25% ; • the Company identified indicators of impairment in its investment in SCFCo as a result of continuing losses and the expectation of continuing weak market conditions and, as a consequence, recognized a $7.7 million impairment charge for an other-than-temporary decline in the fair value of its investment. The fair value of the Company’s investment in SCFCo is estimated with significant inputs that are both observable and unobservable in the market and therefore is considered a Level 3 fair value measurement. The significant unobservable inputs used in the fair value measurement were an estimated earnings multiple of 7 x applied to 2017 forecasted cash flows before interest, taxes, depreciation and amortization (see Note 4); and • the Company marked its investment in SeaJon II to fair value as a consequence of acquiring its partner’s interest resulting in a $1.9 million impairment charge, net of tax, based on the fair value of the acquired interest (see Notes 2 and 4). During the year ended December 31, 2015 , the Company marked its investments to fair value in certain of its 50% or less owned companies as follows: • on December 21, 2015, the Company determined it no longer exercised significant influence over Dorian (see Note 4) and marked its investment, at equity, to fair value. The Level 1 fair value was determined based on the closing quoted market price for Dorian on that date; • the Company marked its equity investment in VA&E to fair value upon the deconsolidation of a previously controlled subsidiary following its contribution to VA&E. The Level 2 fair value was determined based on the value of the equity investment the Company received; and • the Company identified indicators of impairment in its investment in SCFCo as a result of continuing losses and the expectation of continuing weak market conditions and, as a consequence, recognized a $21.5 million impairment charge for an other-than-temporary decline in the fair value of its investment. The fair value of the Company’s investment in SCFCo is estimated with significant inputs that are both observable and unobservable in the market and therefore is considered a Level 3 fair value measurement. The significant unobservable inputs used in the fair value measurement were the construction and mobilization costs of similar new equipment, estimated economic depreciation for comparably aged assets and earnings multiples applied to historical and forecasted cash flows (see Note 4). Notes receivable from third parties. During the year ended December 31, 2016 , the Company recorded $8.5 million in reserves for two of its notes receivables from third parties following non-performance and a decline in the underlying collateral values. The collateral for a note receivable of $6.7 million was determined to have no value. The Company recorded a reserve of $1.8 million for the other note receivable based on a third-party valuation of the underlying collateral using significant inputs that are unobservable in the market and therefore are considered a Level 3 fair value measurement. Due to limited market transactions, the primary valuation methodology applied by the appraiser was an estimated cost approach less estimated economic depreciation for comparably aged assets and less estimated economic obsolescence. The significant unobservable inputs used in the fair value measurement were the estimated construction costs for similar new equipment, estimated economic depreciation of 33% and estimated economic obsolescence of 56% (see Note 6).

Noncontrolling Interests in S36

Noncontrolling Interests in Subsidiaries Noncontrolling Interests (Tables)	12 Months Ended
	Dec. 31, 2016
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interest [Table Text Block]	Noncontrolling interests in the Company’s consolidated subsidiaries as of December 31 were as follows (in thousands): Noncontrolling Interests 2016 2015 Offshore Marine Services: Windcat Workboats 25% $ 5,266 $ 7,484 Other 1.8 % – 30.0% 277 470 Inland River Services: Other 3.0 % – 51.8% 980 1,146 Shipping Services: SEA-Vista 49% 106,054 88,290 Illinois Corn Processing 30% 22,647 22,272 Other 5.0 % – 14.6% 152 457 $ 135,376 $ 120,119

Share Based Compensation (Table

Share Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share Based Compensation Plans	Share Award Transactions. The following transactions have occurred in connection with the Company’s share based compensation plans during the years ended December 31: 2016 2015 2014 Restricted stock awards granted 137,258 135,150 150,145 Restricted stock awards forfeited (2,867 ) — (1,325 ) Director stock awards granted 3,125 3,375 2,625 Restricted Stock Unit Activities: Shares released from Deferred Compensation Plan — (217 ) (216 ) Stock Option Activities: Outstanding as of the beginning of year 1,690,899 1,546,508 1,481,280 Granted 197,550 192,350 199,100 Exercised (113,820 ) (40,461 ) (133,872 ) Forfeited (18,760 ) — — Expired (116,004 ) (7,498 ) — Outstanding as of the end of year 1,639,865 1,690,899 1,546,508 Employee Stock Purchase Plans shares issued 41,924 39,384 30,622 Shares available for issuance under Share Incentive and Employee Stock Purchase Plans as of the end of year 522,341 764,567 1,127,328
Schedule Of Share-based Compensation, Restricted Stock And Restricted Stock Units Activity	During the year ended December 31, 2016 , the number of shares and the weighted average grant price of restricted stock transactions were as follows: Restricted Stock Number of Shares Weighted Average Grant Price Nonvested as of December 31, 2015 387,878 $ 76.93 Granted 137,258 $ 51.10 Vested (141,457 ) $ 76.37 Forfeited (2,867 ) $ 64.49 Nonvested as of December 31, 2016 380,812 $ 67.92
Schedule Of Share-based Compensation, Stock Options, Activity	During the year ended December 31, 2016 , the number of shares, the weighted average grant date fair value and the weighted average exercise price on stock option transactions were as follows: Nonvested Options Vested/Exercisable Options Total Options Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Exercise Price Number of Shares Weighted Average Exercise Price Outstanding, as of December 31, 2015 571,224 $ 22.83 1,119,675 $ 57.64 1,690,899 $ 62.70 Granted 197,550 $ 17.09 — $ — 197,550 $ 57.52 Vested (219,542 ) $ 22.98 219,542 $ 71.76 — $ — Exercised — $ — (113,820 ) $ 48.58 (113,820 ) $ 48.58 Forfeited (18,760 ) $ 22.72 — $ — (18,760 ) $ 71.90 Expired — $ — (116,004 ) $ 60.85 (116,004 ) $ 60.85 Outstanding, as of December 31, 2016 530,472 $ 20.63 1,109,393 $ 61.03 1,639,865 $ 63.09

Commitments And Contingencies S

Commitments And Contingencies Schedule of Operating Lease Payments (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Other Commitments [Table Text Block]	The Company's capital commitments as of December 31, 2016 by year of expected payment were as follows (in thousands): 2017 2018 2019 2020 Total Offshore Marine Services $ 29,272 $ 50,555 $ 13,223 $ 1,800 $ 94,850 Shipping Services 55,430 — — — 55,430 Inland River Services 30,102 — — — 30,102 Illinois Corn Processing 1,678 375 — — 2,053 $ 116,482 $ 50,930 $ 13,223 $ 1,800 $ 182,435
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	Future minimum payments in the years ended December 31 under operating leases that have a remaining term in excess of one year as of December 31, 2016 were as follows (in thousands): Total Minimum Payments Non-cancelable Subleases (1) Net Minimum Payments 2017 $ 59,014 $ (17,345 ) $ 41,669 2018 58,772 (17,345 ) 41,427 2019 43,836 (17,345 ) 26,491 2020 38,570 (17,392 ) 21,178 2021 28,386 (17,345 ) 11,041 Years subsequent to 2021 31,267 (24,045 ) 7,222 ____________________ (1) The total minimum offsetting payments to be received under existing long-term bareboat charter-out arrangements.

Major Customers And Segment I39

Major Customers And Segment Information (Tables)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
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 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the year ended December 31, 2016 Operating Revenues: External customers 215,536 165,140 229,643 177,401 42,783 482 — 830,985 Intersegment 100 2,403 — — 133 — (2,636 ) — 215,636 167,543 229,643 177,401 42,916 482 (2,636 ) 830,985 Costs and Expenses: Operating 166,925 124,460 122,631 158,495 28,561 — (3,259 ) 597,813 Administrative and general 49,308 14,616 27,825 3,011 16,214 1,001 26,606 138,581 Depreciation and amortization 58,069 26,327 31,162 4,299 1,539 — 3,537 124,933 274,302 165,403 181,618 165,805 46,314 1,001 26,884 861,327 Gains (Losses) on Asset Dispositions and Impairments, Net (116,222 ) 3,193 411 — (29,587 ) — — (142,205 ) Operating Income (Loss) (174,888 ) 5,333 48,436 11,596 (32,985 ) (519 ) (29,520 ) (172,547 ) Other Income (Expense): Derivative gains (losses), net 2,995 — — 911 — — (14,131 ) (10,225 ) Foreign currency gains (losses), net (3,312 ) 1,722 (18 ) — (181 ) (1 ) (78 ) (1,868 ) Other, net (1,490 ) (4 ) (6,224 ) — — (12,608 ) 120 (20,206 ) Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax (6,314 ) (15,944 ) (4,697 ) — 305 (704 ) — (27,354 ) Segment Profit (Loss) (183,009 ) (8,893 ) 37,497 12,507 (32,861 ) (13,832 ) Other Income (Expense) not included in Segment Profit (57,402 ) Less Equity in Losses included in Segment Profit 27,354 Loss Before Taxes and Equity Earnings (262,248 ) Capital Expenditures 100,884 36,803 215,837 4,723 2 — 164 358,413 As of December 31, 2016 Property and Equipment: Historical cost 958,759 419,714 727,602 56,708 1,559 — 29,681 2,194,023 Accumulated depreciation (540,619 ) (167,127 ) (258,004 ) (23,689 ) (1,244 ) — (18,184 ) (1,008,867 ) 418,140 252,587 469,598 33,019 315 — 11,497 1,185,156 Construction in progress 123,801 13,003 233,214 701 — — (207 ) 370,512 541,941 265,590 702,812 33,720 315 — 11,290 1,555,668 Investments, at Equity, and Advances to 50% or Less Owned Companies 138,311 69,181 51,620 — 566 54,094 — 313,772 Inventories 3,058 1,602 843 11,133 137 — — 16,773 Goodwill — 2,400 1,852 — 28,506 — — 32,758 Intangible Assets — 12,018 — — 8,060 — — 20,078 Other current and long-term assets, excluding cash and near cash assets (3) 72,810 88,165 29,801 11,850 14,284 11,193 21,576 249,679 Segment Assets 756,120 438,956 786,928 56,703 51,868 65,287 Cash and near cash assets (3) 673,593 Total Assets 2,862,321 ______________________ (1) Operating revenues includes $167.0 million of tangible product sales and operating expenses includes $148.2 million of costs of goods sold. (2) Inventories include raw materials of $1.8 million and work in process of $1.5 million . (3) Cash and near cash assets includes cash, cash equivalents, restricted cash, marketable securities and construction reserve funds	Offshore Marine Services $’000 Inland River Services $’000 Shipping Services $’000 ICP (1)(2) $’000 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the year ended December 31, 2015 Operating Revenues: External customers 368,744 227,601 227,142 166,905 49,838 14,506 — 1,054,736 Intersegment 124 2,881 — — 146 — (3,151 ) — 368,868 230,482 227,142 166,905 49,984 14,506 (3,151 ) 1,054,736 Costs and Expenses: Operating 275,972 168,015 129,039 143,967 21,899 13,054 (3,341 ) 748,605 Administrative and general 53,085 15,567 26,215 2,307 24,096 2,546 32,795 156,611 Depreciation and amortization 61,729 28,632 26,296 3,902 1,711 5 3,712 125,987 390,786 212,214 181,550 150,176 47,706 15,605 33,166 1,031,203 Gains (Losses) on Asset Dispositions and Impairments, Net (17,017 ) 14,868 — — (27 ) (232 ) — (2,408 ) Operating Income (Loss) (38,935 ) 33,136 45,592 16,729 2,251 (1,331 ) (36,317 ) 21,125 Other Income (Expense): Derivative gains (losses), net (2,766 ) 294 — (1,251 ) — (472 ) 2,099 (2,096 ) Foreign currency losses, net (27 ) (3,726 ) (30 ) — (36 ) (11 ) (922 ) (4,752 ) Other, net 261 — 2,053 4,112 19 33 295 6,773 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 8,757 (31,200 ) (18,782 ) — 135 676 — (40,414 ) Segment Profit (Loss) (32,710 ) (1,496 ) 28,833 19,590 2,369 (1,105 ) Other Income (Expense) not included in Segment Profit (51,848 ) Less Equity Losses included in Segment Profit 40,414 Loss Before Taxes and Equity Earnings (30,798 ) Capital Expenditures 87,765 69,736 134,581 4,712 409 — (1,273 ) 295,930 As of December 31, 2015 Property and Equipment: Historical cost 1,102,619 485,144 454,144 47,256 3,338 — 30,700 2,123,201 Accumulated depreciation (546,962 ) (171,271 ) (239,076 ) (19,390 ) (2,834 ) — (14,648 ) (994,181 ) 555,657 313,873 215,068 27,866 504 — 16,052 1,129,020 Construction in progress 97,900 17,807 335,113 5,430 — — (1,645 ) 454,605 653,557 331,680 550,181 33,296 504 — 14,407 1,583,625 Investments, at Equity, and Advances to 50% or Less Owned Companies 130,010 81,363 64,499 — 344 54,887 — 331,103 Inventories 4,000 1,493 701 18,574 — — — 24,768 Goodwill — 2,364 1,852 — 48,124 — — 52,340 Intangible Assets 1,049 5,961 — — 19,382 — — 26,392 Other current and long-term assets, excluding cash and near cash assets (3) 97,488 72,180 28,359 7,739 14,780 16,014 7,014 243,574 Segment Assets 886,104 495,041 645,592 59,609 83,134 70,901 Cash and near cash assets (3) 923,617 Total Assets 3,185,419 ______________________ (1) Operating revenues includes $154.8 million of tangible product sales and operating expenses includes $131.9 million of costs of goods sold. (2) Inventories include raw materials of $2.1 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 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the year ended December 31, 2014 Operating Revenues: External customers 529,761 249,288 214,316 236,293 27,691 62,045 — 1,319,394 Intersegment 183 3,862 — — — — (4,045 ) — 529,944 253,150 214,316 236,293 27,691 62,045 (4,045 ) 1,319,394 Costs and Expenses: Operating 365,092 174,918 112,771 187,849 12,978 59,666 (3,902 ) 909,372 Administrative and general 58,353 15,937 24,518 2,177 19,180 5,957 38,816 164,938 Depreciation and amortization 64,615 29,435 28,420 4,119 1,045 284 3,901 131,819 488,060 220,290 165,709 194,145 33,203 65,907 38,815 1,206,129 Gains (Losses) on Asset Dispositions and Impairments, Net 26,545 29,657 159 — — (1,077 ) (3,306 ) 51,978 Operating Income (Loss) 68,429 62,517 48,766 42,148 (5,512 ) (4,939 ) (46,166 ) 165,243 Other Income (Expense): Derivative gains (losses), net (171 ) — — (3,777 ) — 270 (224 ) (3,902 ) Foreign currency losses, net (1,375 ) (3,335 ) (40 ) — (53 ) (102 ) (1,430 ) (6,335 ) Other, net 14,671 (38 ) (3,630 ) 660 (5,056 ) (3,097 ) (71 ) 3,439 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 10,468 6,673 (661 ) — (465 ) 294 — 16,309 Segment Profit (Loss) 92,022 65,817 44,435 39,031 (11,086 ) (7,574 ) Other Income (Expense) not included in Segment Profit 4,790 Less Equity Earnings included in Segment Profit (16,309 ) Income Before Taxes and Equity Earnings 163,235 Capital Expenditures 83,513 58,481 199,602 3,108 — 148 15,785 360,637 As of December 31, 2014 Property and Equipment Historical cost 1,060,986 491,079 453,862 47,256 3,342 271 30,161 2,086,957 Accumulated depreciation (500,007 ) (159,532 ) (213,072 ) (15,488 ) (3,002 ) (247 ) (10,936 ) (902,284 ) 560,979 331,547 240,790 31,768 340 24 19,225 1,184,673 Construction in progress 87,935 27,415 201,554 718 — 234 144 318,000 648,914 358,962 442,344 32,486 340 258 19,369 1,502,673 Investments, at Equity, and Advances to 50% or Less Owned Companies 115,436 103,688 222,420 — 524 42,089 — 484,157 Inventories 5,570 2,536 1,030 11,170 — 2,477 — 22,783 Goodwill 13,367 2,573 1,852 — 44,967 — — 62,759 Intangible Assets 1,917 6,483 292 — 24,035 — — 32,727 Other current and long-term assets, excluding cash and near cash assets (3) 128,499 99,335 23,910 11,538 26,131 45,547 7,670 342,630 Segment Assets 913,703 573,577 691,848 55,194 95,997 90,371 Cash and near cash assets (3) 786,644 Total Assets 3,234,373 ______________________ (1) Operating revenues includes $224.4 million of tangible product sales and operating expenses includes $175.8 million of costs of goods sold. (2) Inventories include raw materials of $2.2 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.
Revenues Attributed By Geographical Region	The following represents the Company’s revenues attributed by geographical region in which services are provided to customers for the years ended December 31 (in thousands): 2016 2015 2014 Operating Revenues: United States $ 590,310 $ 751,548 $ 925,750 Africa, primarily West Africa 37,764 57,268 70,743 Europe, primarily North Sea 82,730 104,042 112,644 Middle East and Asia 54,950 65,045 69,598 Brazil, Mexico, Central and South America 64,837 76,404 140,460 Other 394 429 199 $ 830,985 $ 1,054,736 $ 1,319,394
Property And Equipment Based Upon The Assets' Physical Location	The following represents the Company’s property and equipment based upon the assets’ physical location as of December 31 (in thousands): 2016 2015 2014 Property and Equipment: United States $ 1,185,917 $ 1,181,586 $ 1,120,765 Africa, primarily West Africa 75,772 73,406 82,495 Europe, primarily North Sea 83,767 72,544 75,382 Middle East and Asia 99,974 129,476 84,598 Brazil, Mexico, Central and South America 110,238 126,613 139,433 $ 1,555,668 $ 1,583,625 $ 1,502,673

Supplemental Information For 40

Supplemental Information For Statements Of Cash Flows (Tables)	12 Months Ended
	Dec. 31, 2016
Supplemental Cash Flow Information [Abstract]
Cash Flow Supplemental Information	Supplemental information for the years ended December 31 was as follows (in thousands): 2016 2015 2014 Income taxes paid $ 11,933 $ 23,791 $ 52,348 Income taxes refunded 3,933 4,550 2,055 Interest paid, excluding capitalized interest 26,662 23,957 24,719 Schedule of Non-Cash Investing and Financing Activities: Company financed sale of equipment and real property 7,950 1,768 45,305 Reclassification of Dorian to marketable securities — 102,509 — Services received to settle notes receivable — 2,500 — Equipment received to settle notes receivable 14,400 — — Non-cash proceeds on the sale of property and equipment 2,000 — —

Quarterly Financial Informati41

Quarterly Financial Information (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Data [Abstract]
Quarterly Financial Information	Three Months Ended Dec. 31, Sept. 30, June 30, March 31, 2016 Operating Revenues $ 213,036 $ 206,983 $ 197,038 $ 213,928 Operating Loss (99,364 ) (33,016 ) (30,151 ) (10,016 ) Net Loss (90,289 ) (34,026 ) (50,933 ) (20,524 ) Net Loss attributable to SEACOR Holdings Inc. (93,749 ) (39,803 ) (55,159 ) (27,186 ) Basic Loss Per Common Share of SEACOR Holdings Inc. $ (5.52 ) $ (2.35 ) $ (3.26 ) $ (1.62 ) Diluted Loss Per Common Share of SEACOR Holdings Inc. $ (5.52 ) $ (2.35 ) $ (3.26 ) $ (1.62 ) 2015 Operating Revenues $ 250,631 $ 261,852 $ 281,609 $ 260,644 Operating Income (Loss) (928 ) 28,221 7,499 (13,667 ) Net Income (Loss) (49,853 ) 16,405 (8,501 ) (17,901 ) Net Income (Loss) attributable to SEACOR Holdings Inc. (56,865 ) 6,965 687 (19,569 ) Basic Earnings (Loss) Per Common Share of SEACOR Holdings Inc. $ (3.36 ) $ 0.40 $ 0.04 $ (1.10 ) Diluted Earnings (Loss) Per Common Share of SEACOR Holdings Inc. $ (3.36 ) $ 0.40 $ 0.04 $ (1.10 )

Nature Of Operations And Acco42

Nature Of Operations And Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2016USD ($)equipmentshares	Dec. 31, 2015USD ($)equipment	Dec. 31, 2014USD ($)equipment
Nature of Operations and Accounting Policies [Line Items]
Inventory write-down	$ 2,700,000	$ 3,000,000	$ 400,000
Depreciation	122,500,000	122,900,000	127,600,000
Capitalized interest	18,500,000	18,500,000	17,000,000
Amortization expense	2,477,000	3,100,000	4,300,000
Asset Impairment Charges	(130,800,000)	(7,100,000)	(4,400,000)
Equity Method Investment, Other than Temporary Impairment	14,700,000		$ 3,300,000
Investment Owned, at Cost	$ 4,432,000	$ 16,045,000
Offshore Marine Services [Member]
Nature of Operations and Accounting Policies [Line Items]
Percentage of Operating Revenues	26.00%	35.00%	40.00%
Asset Impairment Charges	$ (119,700,000)
Goodwill, Impairment Loss		$ 13,400,000
Inland River Services [Member]
Nature of Operations and Accounting Policies [Line Items]
Percentage of Operating Revenues	20.00%	22.00%	19.00%
Shipping Services [Member]
Nature of Operations and Accounting Policies [Line Items]
Percentage of Operating Revenues	28.00%	21.00%	16.00%
Illinois Corn Processing Llc [Member]
Nature of Operations and Accounting Policies [Line Items]
Percentage of Operating Revenues	21.00%	16.00%	18.00%
Witt O'Brien's LLC [Member]
Nature of Operations and Accounting Policies [Line Items]
Percentage of Operating Revenues	5.00%	5.00%	2.00%
Goodwill, Impairment Loss	$ 19,600,000
Dorian LPG [Member]
Nature of Operations and Accounting Policies [Line Items]
Investment Owned, Balance, Shares | shares	9,177,135
Investment Owned, at Fair Value	$ 8.21	$ 11.77
Investment Owned, at Cost	$ 13.66
Offshore Support Vessels Anchor Handling Towing Supply [Member]
Nature of Operations and Accounting Policies [Line Items]
Number of Equipments Removed from Service | equipment	0	0	1
Offshore Support Vessels Anchor Handling Towing Supply [Member] | Offshore Marine Services [Member]
Nature of Operations and Accounting Policies [Line Items]
Asset Impairment Charges	$ (62,800,000)
Property, Plant and Equipment, Useful Life	4 years
Liftboats [Member]
Nature of Operations and Accounting Policies [Line Items]
Number of Equipments Removed from Service | equipment	0	0	1
Liftboats [Member] | Offshore Marine Services [Member]
Nature of Operations and Accounting Policies [Line Items]
Asset Impairment Charges	$ (19,900,000)
Property, Plant and Equipment, Useful Life	6 years
Offshore Support Vessels Specialty [Member] | Offshore Marine Services [Member]
Nature of Operations and Accounting Policies [Line Items]
Asset Impairment Charges	$ (12,700,000)
Property, Plant and Equipment, Useful Life	6 years
Offshore Support Vessels [Member]
Nature of Operations and Accounting Policies [Line Items]
Asset Impairment Charges	$ (120,800,000)	$ (6,600,000)
Number of Equipments Removed from Service | equipment	9	2	14
Offshore Support Vessels [Member] | Offshore Marine Services [Member]
Nature of Operations and Accounting Policies [Line Items]
Asset Impairment Charges	$ (3,600,000)
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Offshore Support Vessels [Member] | Offshore Marine Services [Member]
Nature of Operations and Accounting Policies [Line Items]
Asset Impairment Charges	$ (20,700,000)

Nature Of Operations And Acco43

Nature Of Operations And Accounting Policies (Deferred Revenues Included In Other Current Liabilities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Balance at beginning of period	$ 6,953	$ 6,794	$ 6,592
Revenues deferred during the year	0	159	202
Balance at end of period	6,953	$ 6,953	$ 6,794
Offshore Marine Services [Member]
Balance at end of period	$ 6,800

Nature Of Operations And Acco44

Nature Of Operations And Accounting Policies (Estimated Useful life Of Major Assets) (Details)	12 Months Ended
	Dec. 31, 2016
Offshore Support Vessels [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	20 years
Wind Farm Utility Vessel [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	10 years
Inland River Dry Cargo And Deck Barges [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	20 years
Inland River Liquid Tank Barges [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	25 years
Inland River Towboats and Harbor Boats [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	25 years
U.S.-flag Product Tankers [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	25 years
Short-sea Container\RORO Vessels [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	20 years
Harbor and Offshore Tugs [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	25 years
Ocean Liquid Tank Barge [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	25 years
Terminal And Manufacturing Facilities [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	20 years

Nature Of Operations And Acco45

Nature Of Operations And Accounting Policies (Schedule Of Property And Equipment By Major Classes) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 2,194,023	$ 2,123,201
Accumulated Depreciation	(1,008,867)	(994,181)
Net property and equipment	1,555,668	1,583,625	$ 1,502,673
Property, Plant and Equipment, Other, Gross	1,185,156	1,129,020
Offshore Marine Services [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	958,759	1,102,619
Accumulated Depreciation	(540,619)	(546,962)
Net property and equipment	418,140	555,657
Offshore Marine Services [Member] | Offshore Support Vessels Anchor Handling Towing Supply [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	228,857	301,707
Accumulated Depreciation	(183,757)	(168,534)
Net property and equipment	45,100	133,173
Offshore Marine Services [Member] | Offshore Support Vessels Fast Support [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	251,415	222,720
Accumulated Depreciation	(72,599)	(61,515)
Net property and equipment	178,816	161,205
Offshore Marine Services [Member] | Offshore Support Vessels Supply [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	96,774	139,315
Accumulated Depreciation	(58,028)	(80,862)
Net property and equipment	38,746	58,453
Offshore Marine Services [Member] | Offshore Support Vessels Standby Safety [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	109,436	141,864
Accumulated Depreciation	(88,020)	(113,136)
Net property and equipment	21,416	28,728
Offshore Marine Services [Member] | Offshore Support Vessels Specialty [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	45,765	46,522
Accumulated Depreciation	(24,063)	(21,224)
Net property and equipment	21,702	25,298
Offshore Marine Services [Member] | Liftboats [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	104,356	122,764
Accumulated Depreciation	(45,447)	(36,154)
Net property and equipment	58,909	86,610
Offshore Marine Services [Member] | Wind Farm Utility Vessel [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	60,671	66,950
Accumulated Depreciation	(29,019)	(26,773)
Net property and equipment	31,652	40,177
Offshore Marine Services [Member] | Offshore Support Vessels Machinery and Spares [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	32,921	34,116
Accumulated Depreciation	(20,008)	(19,480)
Net property and equipment	12,913	14,636
Offshore Marine Services [Member] | Property, Plant and Equipment, Other Types [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	28,564	26,661
Accumulated Depreciation	(19,678)	(19,284)
Net property and equipment	8,886	7,377
Inland River Services [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	419,714	485,144
Accumulated Depreciation	(167,127)	(171,271)
Net property and equipment	252,587	313,873
Inland River Services [Member] | Property, Plant and Equipment, Other Types [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	18,145	16,910
Accumulated Depreciation	(6,658)	(4,877)
Net property and equipment	11,487	12,033
Inland River Services [Member] | Inland River Dry Cargo Barges [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	246,237	226,916
Accumulated Depreciation	(97,602)	(86,068)
Net property and equipment	148,635	140,848
Inland River Services [Member] | Inland River Liquid Tank Barges [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	16,114	61,175
Accumulated Depreciation	(1,982)	(14,638)
Net property and equipment	14,132	46,537
Inland River Services [Member] | Inland River Towboats [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	14,675	67,265
Accumulated Depreciation	(1,320)	(15,670)
Net property and equipment	13,355	51,595
Inland River Services [Member] | Inland River Harbor Boats [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	17,338	10,206
Accumulated Depreciation	(5,715)	(5,136)
Net property and equipment	11,623	5,070
Inland River Services [Member] | Inland River Deck Barges [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	12,292	12,293
Accumulated Depreciation	(4,869)	(3,992)
Net property and equipment	7,423	8,301
Inland River Services [Member] | Terminal And Manufacturing Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	94,913	90,379
Accumulated Depreciation	(48,981)	(40,890)
Net property and equipment	45,932	49,489
Shipping Services [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	727,602	454,144
Accumulated Depreciation	(258,004)	(239,076)
Net property and equipment	469,598	215,068
Shipping Services [Member] | Property, Plant and Equipment, Other Types [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	18,825	21,049
Accumulated Depreciation	(6,004)	(8,985)
Net property and equipment	12,821	12,064
Shipping Services [Member] | U.S.-flag Product Tankers [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	546,019	271,141
Accumulated Depreciation	(189,536)	(168,838)
Net property and equipment	356,483	102,303
Shipping Services [Member] | U.S.-flag Harbor Tugs [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	72,877	72,073
Accumulated Depreciation	(34,606)	(37,418)
Net property and equipment	38,271	34,655
Shipping Services [Member] | Foreign-flag Harbor Tugs [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	29,689	29,689
Accumulated Depreciation	(9,480)	(8,291)
Net property and equipment	20,209	21,398
Shipping Services [Member] | Ocean Liquid Tank Barge [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	39,238	39,238
Accumulated Depreciation	(11,604)	(10,175)
Net property and equipment	27,634	29,063
Shipping Services [Member] | Short-sea Container\RORO Vessels [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	20,954	20,954
Accumulated Depreciation	(6,774)	(5,369)
Net property and equipment	14,180	15,585
Illinois Corn Processing Llc [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	56,708	47,256
Accumulated Depreciation	(23,689)	(19,390)
Net property and equipment	33,019	27,866
Illinois Corn Processing Llc [Member] | Terminal And Manufacturing Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	55,028	45,576
Accumulated Depreciation	(23,689)	(19,390)
Net property and equipment	31,339	26,186
Illinois Corn Processing Llc [Member] | Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	1,680	1,680
Accumulated Depreciation	0	0
Net property and equipment	1,680	1,680
Witt O'Brien's LLC [Member] | Property, Plant and Equipment, Other Types [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	1,559	3,338
Accumulated Depreciation	(1,244)	(2,834)
Net property and equipment	315	504
Corporate And Eliminations [Member] | Property, Plant and Equipment, Other Types [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	29,681	30,700
Accumulated Depreciation	(18,184)	(14,648)
Net property and equipment	$ 11,497	$ 16,052

Nature Of Operations And Acco46

Nature Of Operations And Accounting Policies (Schedule Of Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Beginning Balance	$ 33,216	$ 63,888
Acquired intangible assets	(7,098)	(3,157)
Foreign currency translation	9	(78)
Impairment of Intangible Assets, Finite-lived	(10,944)
Finite-Lived Intangible Assets, Period Increase (Decrease)	(432)	(27,437)
Intangible Assets, Gross, Ending Balance	28,947	33,216	$ 63,888
Accumulated Amortization, Beginning Balance	6,824	31,161
Amortization expense	2,477	3,100	4,300
Fully amortized intangible assets, Accumulated Amortization	432	27,437
Accumulated Amortization, Ending Balance	$ 8,869	6,824	31,161
Weighted average remaining contractual life, in years	8 years 219 days
Trademark/Tradenames
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Beginning Balance	$ 4,920	10,681
Acquired intangible assets	0	(1,024)
Foreign currency translation	0	0
Impairment of Intangible Assets, Finite-lived	(1,596)
Finite-Lived Intangible Assets, Period Increase (Decrease)	0	(4,737)
Intangible Assets, Gross, Ending Balance	3,324	4,920	10,681
Accumulated Amortization, Beginning Balance	1,316	5,429
Amortization expense	332	624
Fully amortized intangible assets, Accumulated Amortization	0	4,737
Accumulated Amortization, Ending Balance	$ 1,648	1,316	5,429
Weighted average remaining contractual life, in years	5 years
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Beginning Balance	$ 23,737	48,570
Acquired intangible assets	(1,598)	(2,133)
Foreign currency translation	0	0
Impairment of Intangible Assets, Finite-lived	(8,128)
Finite-Lived Intangible Assets, Period Increase (Decrease)	0	(22,700)
Intangible Assets, Gross, Ending Balance	17,207	23,737	48,570
Accumulated Amortization, Beginning Balance	4,022	24,179
Amortization expense	1,687	2,543
Fully amortized intangible assets, Accumulated Amortization	0	22,700
Accumulated Amortization, Ending Balance	$ 5,709	4,022	24,179
Weighted average remaining contractual life, in years	9 years 88 days
Software/Technology
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Beginning Balance	$ 1,652	1,652
Acquired intangible assets	0	0
Foreign currency translation	0	0
Impairment of Intangible Assets, Finite-lived	(1,220)
Finite-Lived Intangible Assets, Period Increase (Decrease)	(432)	0
Intangible Assets, Gross, Ending Balance	0	1,652	1,652
Accumulated Amortization, Beginning Balance	288	96
Amortization expense	144	192
Fully amortized intangible assets, Accumulated Amortization	432	0
Accumulated Amortization, Ending Balance	$ 0	288	96
Weighted average remaining contractual life, in years	1 day
Acquired Contractual Rights
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Beginning Balance	$ 2,907	2,985
Acquired intangible assets	(5,500)	0
Foreign currency translation	9	(78)
Impairment of Intangible Assets, Finite-lived	0
Finite-Lived Intangible Assets, Period Increase (Decrease)	0	0
Intangible Assets, Gross, Ending Balance	8,416	2,907	2,985
Accumulated Amortization, Beginning Balance	1,198	1,457
Amortization expense	314	(259)
Fully amortized intangible assets, Accumulated Amortization	0	0
Accumulated Amortization, Ending Balance	$ 1,512	$ 1,198	$ 1,457
Weighted average remaining contractual life, in years	8 years 150 days

Nature Of Operations And Acco47

Nature Of Operations And Accounting Policies (Schedule Of Future Amortization Expense Of Intangible Assets) (Details) $ in Thousands	Dec. 31, 2016USD ($)
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
2,017	$ 2,346
2,018	2,173
2,019	2,227
2,020	2,227
2,021	2,227
Years subsequent to 2021	8,878
Total	$ 20,078

Nature Of Operations And Acco48

Nature Of Operations And Accounting Policies (Schedule Of Deferred Gain Activity) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Sale Leaseback and Financed Equipment Sales
Deferred Revenue Arrangement [Line Items]
Balance at beginning of period	$ 123,376	$ 146,534	$ 110,542
Deferred gains arising from equipment sales	9,003	5,984	71,367
Amortization of deferred gains included in operating expenses as a reduction to rental expense	23,272	22,521	18,847
Amortization Of Deferred Gains Included In Gains On Asset Dispositions And Impairments, Net	(602)	(4,954)	(15,686)
Other	(1,697)	(1,667)	(842)
Balance at end of period	106,808	123,376	146,534
Fifty Percent Or Less Owned Subsidiaries
Deferred Revenue Arrangement [Line Items]
Balance at beginning of period	12,533	13,377	14,221
Amortization Of Deferred Gains Included In Gains On Asset Dispositions And Impairments, Net	(1,855)	(844)	(844)
Other	(1,153)	0	0
Balance at end of period	$ 9,525	$ 12,533	$ 13,377

Nature Of Operations And Acco49

Nature Of Operations And Accounting Policies Nature Of Operations And Accounting Policies (Schedule of Accumulated Other Comprehensive Income (Loss))(Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	$ (11,593)	$ (5,528)	$ (3,494)	$ (927)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Parent	(9,331)	(3,129)	(3,949)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax, Portion Attributable to Parent	3,266	1,095	1,382
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	75	(116)	(16)	(257)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax, Portion Attributable to Parent	294	(154)	371
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax, Portion Attributable to Parent	(103)	54	(130)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	4	24	5	(8)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, Portion Attributable to Parent	(31)	29	20
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax, Portion Attributable to Parent	11	(10)	(7)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(11,514)	(5,620)	(3,505)	(1,192)
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(9,068)	(3,254)	(3,558)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	3,174	1,139	1,245
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest	(1,085)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Noncontrolling Interest	(17)	0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Noncontrolling Interest		(442)	(481)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax, Portion Attributable to Noncontrolling Interest	0	0	0
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax, Portion Attributable to Noncontrolling Interest	0	0	0
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, Portion Attributable to Noncontrolling Interest	(13)	13	8
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax, Portion Attributable to Noncontrolling Interest	0	0	0
Other Comprehensive Loss, before Tax	(10,183)	(3,683)	(4,031)
Other Comprehensive Income (Loss), Tax	3,174	1,139	1,245
Other Comprehensive Income (Loss), Net of Tax	(7,009)	(2,544)	(2,786)
Non-Controlling Interests In Subsidiaries [Member]
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(1,613)	(528)	(86)	395
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(17)	0	0	0
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	3	16	3	$ (5)
Other Comprehensive Income (Loss), Net of Tax	$ (1,115)	$ (429)	$ (473)

Nature Of Operations And Acco50

Nature Of Operations And Accounting Policies (Schedule Of Earnings Per Share) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 01, 2015	Nov. 13, 2013	Dec. 11, 2012
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income (Loss) attributable to SEACOR Holdings Inc.	$ (93,749,000)	$ (39,803,000)	$ (55,159,000)	$ (27,186,000)	$ (56,865,000)	$ 6,965,000	$ 687,000	$ (19,569,000)	$ (215,897,000)	$ (68,782,000)	$ 100,132,000
Dilutive Securities, Effect on Basic Earnings Per Share, Options and Restrictive Stock Units									0	0	0
Dilutive Securities, Effect on Basic Earnings Per Share, Dilutive Convertible Securities									0	0	21,156,000
Net Income (Loss) Available to Common Stockholders, Diluted									$ (215,897,000)	$ (68,782,000)	$ 121,288,000
Average o/s Shares, Basic									16,914,928	17,446,137	19,336,280
Incremental Common Shares Attributable to Share-based Payment Arrangements									0	0	403,194
Convertible Securities									0	0	6,025,851
Average o/s Shares, Diluted									16,914,928	17,446,137	25,765,325
Basic Earnings (Loss) Per Common Share of SEACOR Holdings Inc.	$ (5.52)	$ (2.35)	$ (3.26)	$ (1.62)	$ (3.36)	$ 0.40	$ 0.04	$ (1.10)	$ (12.76)	$ (3.94)	$ 5.18
Diluted Earnings (Loss) Per Common Share of SEACOR Holdings Inc.	$ (5.52)	$ (2.35)	$ (3.26)	$ (1.62)	$ (3.36)	$ 0.40	$ 0.04	$ (1.10)	$ (12.76)	$ (3.94)	$ 4.71
Two Point Five Percentage Convertible Notes [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Convertible Securities									1,885,772
Debt Instrument, Interest Rate, Stated Percentage	2.50%								2.50%					2.50%
Three Point Zero Percentage Convertible Notes [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Convertible Securities									1,825,326
Debt Instrument, Interest Rate, Stated Percentage	3.00%								3.00%				3.00%
Three Point Seven Five Percentage Convertible Notes [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Convertible Securities									2,243,500
Debt Instrument, Interest Rate, Stated Percentage												3.75%
Stock Compensation Plan [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount									2,020,677	2,078,777	407,698
Convertible Debt Securities [Member] | Two Point Five Percentage Convertible Notes [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount									2,664,208	4,148,327
Convertible Debt Securities [Member] | Three Point Zero Percentage Convertible Notes [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount									1,825,326	1,825,326
Convertible Debt Securities [Member] | Three Point Seven Five Percentage Convertible Notes [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount									2,243,500	190,544

Business Acquisitions (Details)

Business Acquisitions (Details)	12 Months Ended
	Dec. 31, 2016USD ($)equipment	Dec. 31, 2015USD ($)equipment	Dec. 31, 2014USD ($)equipment	Dec. 12, 2016USD ($)	Dec. 02, 2016	Jul. 11, 2014
Business Acquisition [Line Items]
Goodwill, Gross	$ 0	$ 3,157,000	$ 44,967,000
Restricted cash	275,000	0	0
Trade and other receivables	2,187,000	0	31,079,000
Other current assets	150,000	0	1,925,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	(3,437,000)	0	(49,968,000)
Property and Equipment	17,132,000	0	519,000
Intangible Assets	7,098,000	(3,157,000)	24,901,000
Other Assets	0	0	111,000
Accounts payable	238,000	0	(1,709,000)
Other current liabilities	(13,000)	0	(12,274,000)
Long-Term Debt	(3,091,000)	0	(3,266,000)
Deferred Income Taxes	0	0	91,000
Other Liabilities	0	0	(1,376,000)
Purchase price	20,539,000	0	35,000,000
Cash Acquired from Acquisition	900,000		400,000
Witt O'Brien's LLC [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired						45.80%
Payments to Acquire Businesses, Gross			$ 35,400,000
Goodwill, Gross		$ 48,100,000
Central Contracting & Marine, Inc. [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 18,100,000
Number Of Equipments Acquired | equipment	5
SeaJon II [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired					50.00%
Payments to Acquire Businesses, Gross	$ 3,400,000
Number Of Equipments Acquired | equipment	1
Cypress CKOR LLC [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired				100.00%
Payments to Acquire Businesses, Gross	$ 1
Number Of Equipments Acquired | equipment	1
Long-Term Debt				$ (3,100,000)
Inland River Harbor Boats [Member] | Central Contracting & Marine, Inc. [Member]
Business Acquisition [Line Items]
Number Of Equipments Acquired | equipment	5
U.S-flag Offshore Tug [Member] | SeaJon II [Member]
Business Acquisition [Line Items]
Number Of Equipments Acquired | equipment	1
Offshore Support Vessels [Member]
Business Acquisition [Line Items]
Number Of Equipments Acquired | equipment	17	6	7
Offshore Support Vessels [Member] | Cypress CKOR LLC [Member]
Business Acquisition [Line Items]
Number Of Equipments Acquired | equipment	1

Equipment Acquisitions And Di52

Equipment Acquisitions And Dispositions (Major Equipment Deliveries) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)equipment	Dec. 31, 2015USD ($)equipment	Dec. 31, 2014USD ($)equipment
Payments to Acquire Property, Plant, and Equipment | $	$ 358,413	$ 295,930	$ 360,637
Offshore Support Vessels Fast Support [Member]
Number Of Equipments Acquired	12	3	3
Offshore Support Vessels Supply [Member]
Number Of Equipments Acquired	2	1	2
Offshore Support Vessels Specialty [Member]
Number Of Equipments Acquired	1	0	0
Wind Farm Utility Vessel [Member]
Number Of Equipments Acquired	2	2	2
Offshore Support Vessels [Member]
Number Of Equipments Acquired	17	6	7
Inland River Dry Cargo Barges [Member]
Number Of Equipments Acquired	46	0	65
Inland River Liquid Tank Barges - 10,000 Barrel [Member]
Number Of Equipments Acquired	0	8	0
Inland River Specialty Barges [Member]
Number Of Equipments Acquired	0	4	0
Inland River Towboats [Member]
Number Of Equipments Acquired	2	9	1
U S Flag Tankers [Member]
Number Of Equipments Acquired	3	0	0
Short-sea Container\RORO Vessels [Member]
Number Of Equipments Acquired	0	0	1
U.S.-flag Harbor Tugs [Member]
Number Of Equipments Acquired	1	0	0
Central Contracting & Marine, Inc. [Member]
Number Of Equipments Acquired	5
Cypress CKOR LLC [Member]
Number Of Equipments Acquired	1
Cypress CKOR LLC [Member] | Offshore Support Vessels [Member]
Number Of Equipments Acquired	1
SeaJon II [Member]
Number Of Equipments Acquired	1
Fair Value Hedging [Member]
Payments to Acquire Property, Plant, and Equipment | $	$ 358,786

Equipment Acquisitions And Di53

Equipment Acquisitions And Dispositions (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Sales Price Of Equipment	$ 194,400	$ 97,200	$ 300,100
Proceeds from Sale of Property, Plant, and Equipment	184,947	95,460	254,763
Proceeds from Issuance of Secured Debt	8,000	1,700	45,300
Gain (Loss) on Disposition of Property Plant Equipment	14,700	18,300	111,200
Increase (Decrease) in Deferred Charges	9,000	6,000	71,400
Sale Leaseback Transaction, Net Proceeds, Investing Activities	61,000	35,300	141,800
Sale Leaseback Transaction, Deferred Gain, Net	8,200	$ 4,200	$ 52,000
Deposits	500
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Business Acquisition [Line Items]
Proceeds from Sale of Property, Plant, and Equipment	184,400
Offshore Support Vessels Anchor Handling Towing Supply [Member]
Business Acquisition [Line Items]
Sale Leaseback Transaction, Description of Asset(s)			1
Offshore Support Vessels Fast Support [Member]
Business Acquisition [Line Items]
Sale Leaseback Transaction, Description of Asset(s)			1
Inland River Towboats [Member]
Business Acquisition [Line Items]
Sale Leaseback Transaction, Description of Asset(s)		4
Liftboats [Member]
Business Acquisition [Line Items]
Sale Leaseback Transaction, Description of Asset(s)			1
U.S.-flag Harbor Tugs [Member]
Business Acquisition [Line Items]
Noncash or Part Noncash Divestiture, Amount of Consideration Received	$ 2,000	$ 0	$ 0
U.S.-flag Product Tankers [Member]
Business Acquisition [Line Items]
Sale Leaseback Transaction, Description of Asset(s)	1		1
Sale Leaseback Transaction, Lease Terms	76
Minimum [Member]
Business Acquisition [Line Items]
Sale Leaseback Transaction, Lease Terms			10
Minimum [Member] | U.S.-flag Product Tankers [Member]
Business Acquisition [Line Items]
Sale Leaseback Transaction, Lease Terms	69
Maximum [Member]
Business Acquisition [Line Items]
Sale Leaseback Transaction, Lease Terms		84	84
Maximum [Member] | U.S.-flag Product Tankers [Member]
Business Acquisition [Line Items]
Sale Leaseback Transaction, Lease Terms	85
Inland River Joint Venture [Member] | Inland River Towboats [Member]
Business Acquisition [Line Items]
Property, Plant and Equipment, Dispositions			1
Inland River Joint Venture [Member] | Inland River Dry Cargo Barges [Member]
Business Acquisition [Line Items]
Property, Plant and Equipment, Dispositions			20
Offshore Marine Services Joint Ventures [Member] | Offshore Support Vessels [Member]
Business Acquisition [Line Items]
Property, Plant and Equipment, Dispositions			2
Gain (Loss) on Asset Dispositions and Impairments, Net [Member]
Business Acquisition [Line Items]
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property	$ 5,700	$ 12,300	$ 39,800
Amortization of Deferred Charges	$ 2,500	$ 5,800	16,500
Financing Receivable [Member]
Business Acquisition [Line Items]
Sales Price Of Equipment			45,300
Increase (Decrease) in Deferred Charges			$ 19,400

Equipment Acquisitions And Di54

Equipment Acquisitions And Dispositions (Major Equipment Dispositions) (Details)	12 Months Ended
	Dec. 31, 2016USD ($)equipment	Dec. 31, 2015USD ($)equipment	Dec. 31, 2014USD ($)equipment
Offshore Support Vessels Standby Safety [Member]
Number of Equipments Removed from Service	4	0	0
Offshore Support Vessels Anchor Handling Towing Supply [Member]
Number of Equipments Removed from Service	0	0	1
Offshore Support Vessels Fast Support [Member]
Number of Equipments Removed from Service	0	1	7
Offshore Support Vessels Supply [Member]
Number of Equipments Removed from Service	5	1	4
Liftboats [Member]
Number of Equipments Removed from Service	0	0	1
Wind Farm Utility Vessel [Member]
Number of Equipments Removed from Service	0	0	1
Offshore Support Vessels [Member]
Number of Equipments Removed from Service	9	2	14
Inland River Dry Cargo Barges [Member]
Number of Equipments Removed from Service	0	0	80
Inland River Liquid Tank Barges - 10,000 Barrel [Member]
Number of Equipments Removed from Service	0	35	0
Inland River Liquid Tank Barges - 30,000 Barrel [Member]
Number of Equipments Removed from Service	19	0	0
Inland River Deck Barges [Member]
Number of Equipments Removed from Service | $	0	12	0
Inland River Towboats [Member]
Number of Equipments Removed from Service	14	4	5
U.S.-flag Product Tankers [Member]
Number of Equipments Removed from Service	1	0	1
Short-sea Container\RORO Vessels [Member]
Number of Equipments Removed from Service	0	0	2
U.S.-flag Harbor Tugs [Member]
Number of Equipments Removed from Service	2	0	0

Investments, At Equity, And A55

Investments, At Equity, And Advances To 50% Or Less Owned Companies (Investments, At Equity, And Advances To 50% Or Less Owned Companies) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Jun. 01, 2015
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 313,772	$ 331,103
Falcon Global [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%
OSV Partners [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	30.40%
Trailer Bridge Inc [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	55.30%
VA&E [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	41.30%		81.10%
Offshore Marine Services [Member] | MexMar [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	49.00%
Equity Method Investments	$ 63,404	50,163
Offshore Marine Services [Member] | Falcon Global [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%
Equity Method Investments	$ 18,539	17,951
Offshore Marine Services [Member] | Dynamic Offshore Drilling Ltd. [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	19.00%
Equity Method Investments	$ 15,871	14,172
Offshore Marine Services [Member] | Sea-Cat Crewzer II [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%
Equity Method Investments	$ 11,246	11,339
Offshore Marine Services [Member] | OSV Partners [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	30.40%
Equity Method Investments	$ 9,245	11,374
Offshore Marine Services [Member] | Nautical Power [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%
Equity Method Investments	$ 6,413	6,412
Offshore Marine Services [Member] | Sea Cat Crewzer [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%
Equity Method Investments	$ 4,088	2,701
Offshore Marine Services [Member] | Other Offshore Marine Services Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 9,505	15,898
Offshore Marine Services [Member] | Other Offshore Marine Services Joint Ventures [Member] | Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	20.00%
Offshore Marine Services [Member] | Other Offshore Marine Services Joint Ventures [Member] | Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%
Offshore Marine Services [Member] | Offshore Marine Services Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 138,311	130,010
Inland River Services [Member] | SCFCo Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%
Equity Method Investments	$ 46,028	57,437
Inland River Services [Member] | Bunge-SCF Grain [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%
Equity Method Investments	$ 16,176	16,695
Inland River Services [Member] | SCF Bunge Marine [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%
Equity Method Investments	$ 4,233	4,544
Inland River Services [Member] | Other Inland River Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%
Equity Method Investments	$ 2,744	2,687
Inland River Services [Member] | Inland River Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 69,181	81,363
Shipping Services [Member] | Trailer Bridge Inc [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	55.30%
Equity Method Investments	$ 43,050	41,710
Shipping Services [Member] | Sea-Access [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%
Equity Method Investments	$ 0	8,414
Shipping Services [Member] | SeaJon [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%
Equity Method Investments	$ 8,570	7,987
Shipping Services [Member] | SeaJon II [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%
Equity Method Investments	$ 0	6,388
Shipping Services [Member] | Shipping Services Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	51,620	64,499
Corporate and Other [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 54,660	55,231
Corporate and Other [Member] | Hawker Pacific Airservices Limited [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	34.20%
Equity Method Investments	$ 20,418	20,964
Corporate and Other [Member] | VA&E [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	41.30%
Equity Method Investments	$ 11,133	13,954
Corporate and Other [Member] | Avion Pacific Limited [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	39.10%
Equity Method Investments	$ 14,783	11,994
Corporate and Other [Member] | Cleancor [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%
Equity Method Investments	$ 5,373	5,613
Corporate and Other [Member] | Other Corporate Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 2,953	$ 2,706
Corporate and Other [Member] | Other Corporate Joint Ventures [Member] | Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	34.00%
Corporate and Other [Member] | Other Corporate Joint Ventures [Member] | Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of equity interest	50.00%

Investments, At Equity, And A56

Investments, At Equity, And Advances To 50% Or Less Owned Companies (Summarized Financial Information For The Company's Investments, At Equity) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current assets	$ 745,872	$ 603,446
Noncurrent assets	1,009,317	1,066,610
Current liabilities	622,530	401,987
Noncurrent liabilities	458,922	674,896
Operating Revenues	1,359,370	1,281,708	$ 1,175,872
Costs and Expenses: Operating and administrative	1,204,496	1,085,518	1,021,730
Costs and Expenses: Depreciation	80,784	94,105	61,233
Total costs and expenses	1,285,280	1,179,623	1,082,963
Gain (Loss) on Asset Dispositions	(27,900)	(2,174)	368
Operating Income	46,190	99,911	93,277
Net Income (Loss)	(34,569)	18,835	$ 29,296
Dorian LPG [Member]
Current assets	98,254	198,058
Noncurrent assets	1,724,758	812,164
Current liabilities	88,021	20,662
Noncurrent liabilities	759,636	125,716
Operating Revenues	239,206	78,666
Operating Income	126,820	20,494
Net Income (Loss)	$ 118,356	$ 15,122

Investments, At Equity, And A57

Investments, At Equity, And Advances To 50% Or Less Owned Companies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2016USD ($)equipment	Dec. 31, 2015USD ($)equipmentshares	Dec. 31, 2014USD ($)equipment	Dec. 02, 2016	Nov. 30, 2016USD ($)	Jun. 01, 2015
Schedule of Equity Method Investments [Line Items]
Cumulative undistributed net earnings of 50% or less owned companies accounted for by the equity method included in the Company's consolidated retained earnings	$ 7,800,000	$ 19,900,000
Proceeds from Issuance of Secured Debt	8,000,000	1,700,000	$ 45,300,000
Equity Method Investment, Other than Temporary Impairment	14,700,000		3,300,000
Letters of Credit Outstanding, Amount	26,200,000
Guarantor Obligations, Maximum Exposure, Undiscounted	1,900,000
Asset Impairment Charges	130,800,000	7,100,000	4,400,000
MexMar [Member]
Schedule of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions	$ 7,400,000	7,900,000	$ 2,900,000
Number Of Equipments Acquired	2		2
Repayments of Secured Debt		15,000,000	$ 10,700,000
Property, Plant and Equipment, Additions	$ 34,000,000		32,000,000
Payments to Acquire Machinery and Equipment			6,400,000
Proceeds from Issuance of Secured Debt			25,600,000
Related Party Transaction, Revenues from Transactions with Related Party	300,000	400,000	300,000
Related party transaction expense	5,100,000	11,600,000	13,500,000
Falcon Global [Member]
Schedule of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions	7,700,000	15,700,000	3,400,000
Equity Method Investment, Other than Temporary Impairment	$ 6,400,000
Equity Method Investment, Ownership Percentage	50.00%
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 51,800,000
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity	6,400,000
Sea-Cat Crewzer II [Member]
Schedule of Equity Method Investments [Line Items]
Related Party Transaction, Revenues from Transactions with Related Party	700,000	700,000	700,000
Guarantor Obligations, Maximum Exposure, Undiscounted	11,600,000
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital		1,800,000
Partners' Capital Account, Return of Capital			14,000,000
OSV Partners [Member]
Schedule of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions	1,200,000	1,400,000	5,100,000
Related Party Transaction, Revenues from Transactions with Related Party	$ 500,000	1,200,000	1,200,000
Equity Method Investment, Ownership Percentage	30.40%
Sea Cat Crewzer [Member]
Schedule of Equity Method Investments [Line Items]
Related Party Transaction, Revenues from Transactions with Related Party	$ 700,000	700,000	700,000
Related party transaction expense	4,300,000	5,900,000	6,700,000
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 10,300,000
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital		1,300,000	3,300,000
Partners' Capital Account, Return of Capital			3,200,000
Other Offshore Marine Services Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Number of Equipment Operated | equipment	10
Partners' Capital Account, Contributions	$ 500,000		800,000
Repayments of Advances		(200,000)	(600,000)
Related Party Transaction, Revenues from Transactions with Related Party	800,000	800,000	600,000
Equity Method Investment, Other than Temporary Impairment	500,000
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital	800,000	900,000	1,000,000
Partners' Capital Account, Return of Capital			200,000
Allocable share of uncalled capital	1,800,000
Guarantee of outstanding charter receivables	400,000
SCFCo Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions	800,000	18,000,000	19,700,000
Proceeds from Issuance of Secured Debt			13,000,000
Repayments of Advances		(14,000,000)	(1,000,000)
Related Party Transaction, Revenues from Transactions with Related Party	100,000	200,000
Equity Method Investment, Other than Temporary Impairment	7,700,000	21,500,000
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity	28,500,000
Payments for Advance to Affiliate	1,800,000		23,500,000
Asset Impairment Charges		21,500,000
Advanced to joint ventures	30,300,000
Bunge-SCF Grain [Member]
Schedule of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions			2,000,000
Repayments of Advances		(2,000,000)
Related Party Transaction, Revenues from Transactions with Related Party	1,000,000	1,000,000	1,000,000
Related party transaction expense	7,200,000	10,800,000	7,800,000
Payments for Advance to Affiliate			2,000,000
Advanced to joint ventures	$ 7,000,000
SCF Bunge Marine [Member]
Schedule of Equity Method Investments [Line Items]
Number of Equipment Operated | equipment	6
Related Party Transaction, Revenues from Transactions with Related Party	$ 35,000,000	41,700,000	41,600,000
Related party transaction expense	40,200,000	47,900,000	46,600,000
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital	2,500,000	$ 4,000,000	4,500,000
Other Inland River Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Partners' Capital Account, Return of Capital			$ 2,100,000
Dorian LPG [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		15.90%	16.10%
Business Combination, Separately Recognized Transactions, Net Gains and Losses		$ 32,300,000	$ 4,400,000
Sale of Stock, Number of Shares Issued in Transaction | shares		150,000
Proceeds from Sale and Maturity of Marketable Securities		$ 2,300,000
Trailer Bridge Inc [Member]
Schedule of Equity Method Investments [Line Items]
Repayments of Advances		(18,700,000)	(2,100,000)
Related Party Transaction, Revenues from Transactions with Related Party	$ 300,000	800,000
Equity Method Investment, Ownership Percentage	55.30%
Payments for Advance to Affiliate	$ 1,700,000
Advanced to joint ventures	3,900,000
Business Combination, Separately Recognized Transactions, Net Gains and Losses	(2,200,000)
Sea-Access [Member]
Schedule of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions			16,700,000
Related Party Transaction, Revenues from Transactions with Related Party	500,000	1,000,000	100,000
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital	2,000,000	4,400,000
Partners' Capital Account, Return of Capital	8,400,000	8,300,000
SeaJon [Member]
Schedule of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions			2,300,000
Guarantor Obligations, Maximum Exposure, Undiscounted	5,000,000
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital	600,000	600,000
Partners' Capital Account, Return of Capital			5,400,000
SeaJon II [Member]
Schedule of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions		1,000,000	600,000
Related Party Transaction, Revenues from Transactions with Related Party	100,000	100,000
Partners' Capital Account, Return of Capital		300,000
Partners' Capital Account, Contributions, Noncash			5,400,000
Business Combination, Separately Recognized Transactions, Net Gains and Losses	1,900,000
Hawker Pacific Airservices Limited [Member]
Schedule of Equity Method Investments [Line Items]
Related Party Transaction, Revenues from Transactions with Related Party	300,000	300,000	500,000
Letters of Credit Outstanding, Amount	6,500,000
VA&E [Member]
Schedule of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions		3,500,000
Repayments of Advances	$ (1,100,000)
Equity Method Investment, Ownership Percentage	41.30%					81.10%
Payments for Advance to Affiliate		1,000,000
Advanced to joint ventures	$ 3,600,000
Line of Credit Facility, Maximum Borrowing Capacity					$ 6,000,000
Proceeds from Unsecured Lines of Credit	10,000,000	15,000,000
Repayments of Long-term Lines of Credit	12,400,000	11,500,000
Avion Pacific Limited [Member]
Schedule of Equity Method Investments [Line Items]
Repayments of Advances		(3,000,000)	(4,000,000)
Payments for Advance to Affiliate	3,000,000		3,000,000
Advanced to joint ventures	3,000,000
Cleancor [Member]
Schedule of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions			4,800,000
Payments for Advance to Affiliate		2,000,000
Advanced to joint ventures	1,900,000
Witt O'Brien's LLC [Member]
Schedule of Equity Method Investments [Line Items]
Related Party Transaction, Revenues from Transactions with Related Party			100,000
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital			400,000
Partners' Capital Account, Return of Capital			400,000
Other Corporate Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Partners' Capital Account, Contributions		$ 200,000	1,700,000
Partners' Capital Account, Return of Capital			$ 100,000
Payments for Advance to Affiliate	$ 800,000
Offshore Support Vessels [Member]
Schedule of Equity Method Investments [Line Items]
Number Of Equipments Acquired | equipment	17	6	7
Asset Impairment Charges	$ 120,800,000	$ 6,600,000
Offshore Support Vessels [Member] | MexMar [Member]
Schedule of Equity Method Investments [Line Items]
Number of Equipment Operated | equipment	15
Offshore Support Vessels [Member] | Sea-Cat Crewzer II [Member]
Schedule of Equity Method Investments [Line Items]
Number of Equipment Operated | equipment	2
Offshore Support Vessels [Member] | OSV Partners [Member]
Schedule of Equity Method Investments [Line Items]
Number of Equipment Operated | equipment	5
Number Of Equipments Acquired | equipment			2
Payments to Acquire Machinery and Equipment			$ 27,700,000
Offshore Support Vessels [Member] | Nautical Power [Member]
Schedule of Equity Method Investments [Line Items]
Number of Equipment Operated | equipment	1
Offshore Support Vessels [Member] | Sea Cat Crewzer [Member]
Schedule of Equity Method Investments [Line Items]
Number of Equipment Operated | equipment	2
Liftboats [Member] | Falcon Global [Member]
Schedule of Equity Method Investments [Line Items]
Number of Equipment Operated | equipment	2
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 3,800,000
Inland River Towboats [Member]
Schedule of Equity Method Investments [Line Items]
Number Of Equipments Acquired | equipment	2	9	1
Inland River Towboats [Member] | SCFCo Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Number Of Equipments Acquired | equipment			1
Inland River Dry Cargo Barges [Member]
Schedule of Equity Method Investments [Line Items]
Number Of Equipments Acquired | equipment	46	0	65
Inland River Dry Cargo Barges [Member] | SCFCo Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Number Of Equipments Acquired | equipment			20
U.S.-flag Harbor Tugs [Member]
Schedule of Equity Method Investments [Line Items]
Number Of Equipments Acquired | equipment	1	0	0
U.S.-flag Harbor Tugs [Member] | Trailer Bridge Inc [Member]
Schedule of Equity Method Investments [Line Items]
Related Party Transaction, Revenues from Transactions with Related Party	$ 3,000,000	$ 400,000	$ 2,000,000
Offshore Support Vessels [Member] | OSV Partners [Member]
Schedule of Equity Method Investments [Line Items]
Asset Impairment Charges	1,000,000
Offshore Support Vessels [Member] | Other Offshore Marine Services Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Asset Impairment Charges	$ 2,700,000	$ 2,000,000
SeaJon II [Member]
Schedule of Equity Method Investments [Line Items]
Number Of Equipments Acquired | equipment	1
Business Acquisition, Percentage of Voting Interests Acquired				50.00%
Payments to Acquire Businesses, Gross	$ 3,400,000
Subordinated Debt [Member] | VA&E [Member]
Schedule of Equity Method Investments [Line Items]
Advanced to joint ventures	$ 3,500,000				1,000,000
Long-term Debt [Member] | VA&E [Member]
Schedule of Equity Method Investments [Line Items]
Advanced to joint ventures					$ 1,100,000

Construction Reserve Funds (Det

Construction Reserve Funds (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other Restricted Assets [Abstract]
Withdrawals	$ 130,446	$ 47,472	$ 131,167
Deposits	29,000	34,459	147,450
Construction Reserve Fund Activity Net	$ (101,446)	$ (13,013)	$ 16,283

Third Party Notes Receivable (D

Third Party Notes Receivable (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Notes, Loans and Financing Receivable, Net, Noncurrent [Abstract]
Loans and Leases Receivable, Gross	$ 12.6	$ 24.9
Notes receivable third party	(9.4)	(9.6)	$ (19)
Proceeds from Collection of Notes Receivable	6.8	$ 10.8	10
Proceeds from Collection of Lease Receivables			$ 0.6
Provision for Loan and Lease Losses	$ 8.5

Long-Term Debt (Schedule Of Com

Long-Term Debt (Schedule Of Company's Borrowings) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 1,084,814	$ 1,149,753
Portion due within one year, net of related debt discount and issuance costs	183,602	35,531
Debt discount included in long-term debt	(39,537)	(62,914)
Debt issuance costs included in long-term debt	(12,904)	(16,449)
Long-term Debt, Excluding Current Maturities	848,771	1,034,859
Three Point Zero Percentage Convertible Notes [Member]
Debt Instrument [Line Items]
Convertible Debt	230,000	230,000
Debt discount included in long-term debt	(29,800)	(36,200)
Debt issuance costs included in long-term debt	(3,000)	(3,700)
Two Point Five Percentage Convertible Notes [Member]
Debt Instrument [Line Items]
Convertible Debt	157,128	284,500
Debt discount included in long-term debt	(4,800)	(17,300)
Debt issuance costs included in long-term debt	(800)	(2,800)
7.375% Senior Notes [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent	160,699	195,941
Debt discount included in long-term debt	(400)	(600)
Debt issuance costs included in long-term debt	(500)	(900)
Three Point Seven Five Percentage Convertible Notes [Member]
Debt Instrument [Line Items]
Debt discount included in long-term debt	(4,100)	(8,200)
Debt issuance costs included in long-term debt	(3,100)	(6,200)
SEA-Vista Credit Facility [Member]
Debt Instrument [Line Items]
Debt issuance costs included in long-term debt	(2,000)	(2,700)
Other Debt Obligations [Member]
Debt Instrument [Line Items]
Other Long-term Debt	82,742	54,287
Debt discount included in long-term debt	(500)	(600)
Debt issuance costs included in long-term debt	(3,500)	(200)
SEACOR Marine Holdings Inc. [Member] | Three Point Seven Five Percentage Convertible Notes [Member]
Debt Instrument [Line Items]
Convertible Debt	175,000	175,000
Sea-Vista [Member] | SEA-Vista Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 279,245	$ 210,025

Long-Term Debt (Schedule Of Lon

Long-Term Debt (Schedule Of Long-Term Debt Maturities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 11, 2012
Debt Instrument [Line Items]
2,017	$ 189,164
2,018	21,766
2,019	183,212
2,020	238,846
2,021	25,800
Years subsequent to 2021	426,026
Long-term Debt, Gross	$ 1,084,814	$ 1,149,753
Two Point Five Percentage Convertible Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.50%		2.50%

Long-Term Debt (Narrative) (Sen

Long-Term Debt (Narrative) (Senior Notes And Convertible Debentures) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 15, 2016	Dec. 01, 2015	Jun. 01, 2015	Apr. 15, 2015	Apr. 09, 2015	Nov. 13, 2013	Dec. 11, 2012	Sep. 24, 2009
Debt Instrument [Line Items]
Common Stock, Par or Stated Value Per Share		$ 0.01	$ 0.01
Stock Repurchase Program, Authorized Amount							$ 150,000,000
Convertible Securities		0	0	6,025,851
Debt extinguishment gains (losses), net		$ 5,184,000	$ (28,497,000)	$ 0
Letters of credit outstanding amount		26,200,000
Guarantor Obligations, Maximum Exposure, Undiscounted		1,900,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 147,000,000
Sea-Vista [Member]
Debt Instrument [Line Items]
Payments of Debt Issuance Costs			3,100,000
Line of Credit Facility, Maximum Borrowing Capacity										$ 300,000,000
Sea-Vista [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Mandatory Prepayment Balance			75,000,000
Debt Instrument, Prepayment Increments			$ 1,000,000
Sea-Vista [Member] | Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		2.00%
Sea-Vista [Member] | Minimum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.25%
Sea-Vista [Member] | Maximum [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		2.75%
Sea-Vista [Member] | Maximum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.75%
Illinois Corn Processing Llc [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate			2.00%
Three Point Zero Percentage Convertible Notes [Member]
Debt Instrument [Line Items]
Debt instrument, stated percentage		3.00%										3.00%
Aggregate principal amount												$ 230,000,000
Bond Trading Price Triggering Contingent Interest, Minimum					$ 1,200
Individual Bond, Face Value												$ 1,000
Contingent Interest Rate												0.45%
Debt Instrument, Convertible, Conversion Ratio					7.9362
Convertible Securities		1,825,326
Bond Redemption Percentage		100.00%			100.00%
Convertible Debt		$ 230,000,000	$ 230,000,000
Debt Instrument, Interest Rate, Effective Percentage		7.40%
Two Point Five Percentage Convertible Notes [Member]
Debt Instrument [Line Items]
Debt instrument, stated percentage		2.50%											2.50%
Aggregate principal amount													$ 350,000,000
Bond Trading Price Triggering Contingent Interest, Minimum						$ 1,200
Individual Bond, Face Value													$ 1,000
Contingent Interest Rate													0.25%
Debt Instrument, Convertible, Conversion Ratio		12.0015
Convertible Securities		1,885,772
Bond Redemption Percentage			100.00%			100.00%
Convertible Debt		$ 157,128,000	$ 284,500,000
Debt Instrument, Interest Rate, Effective Percentage		6.50%
Debt Instrument, Repurchased Face Amount		$ 127,400,000	65,500,000
Debt Instrument, Repurchase Amount		124,700,000	62,600,000
Debt extinguishment gains (losses), net		3,300,000	1,100,000
Redemption Premium						$ 55
Two Point Five Percentage Convertible Notes [Member] | Additional Paid-In Capital [Member]
Debt Instrument [Line Items]
Debt Instrument, Repurchase Amount		7,400,000	3,000,000
7.375% Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, stated percentage														7.375%
Aggregate principal amount														$ 250,000,000
Debt Instrument, Repurchased Face Amount		35,200,000	37,600,000
Debt Instrument, Repurchase Amount		33,100,000	37,900,000
Debt extinguishment gains (losses), net		$ 1,900,000	600,000
Three Point Seven Five Percentage Convertible Notes [Member]
Debt Instrument [Line Items]
Debt instrument, stated percentage								3.75%
Aggregate principal amount								$ 175,000,000
Debt Instrument, Convertible, Conversion Ratio		12.82
Convertible Securities		2,243,500
Payments of Debt Issuance Costs			$ 6,400,000
Debt Instrument, Interest Rate, Effective Percentage			8.70%
Embedded Derivative, Fair Value of Embedded Derivative Liability								8,500,000
Three Point Seven Five Percentage Convertible Notes [Member] | SEACOR Marine Holdings Inc. [Member]
Debt Instrument [Line Items]
Individual Bond, Face Value								$ 1,000
Debt Instrument, Convertible, Conversion Ratio			23.26
Convertible Securities		4,070,500
Bond Redemption Percentage			100.00%
Convertible Debt		$ 175,000,000	$ 175,000,000
Revolving Credit Facility [Member] | Sea-Vista [Member]
Debt Instrument [Line Items]
Debt Instrument, Unused Borrowing Capacity, Amount										100,000,000
Proceeds from Lines of Credit		87,000,000	30,000,000
Repayments of Lines of Credit		14,000,000	17,000,000
Line of Credit Facility, Current Borrowing Capacity		14,000,000
Revolving Credit Facility [Member] | Sea-Vista [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Proceeds from Lines of Credit	$ 14,000,000
Revolving Credit Facility [Member] | Illinois Corn Processing Llc [Member]
Debt Instrument [Line Items]
Payments of Debt Issuance Costs			300,000
Line of Credit Facility, Maximum Borrowing Capacity											$ 20,000,000
Line of Credit Facility, Current Borrowing Capacity		16,200,000									$ 30,000,000
Term A-1 Loan [Member] | Sea-Vista [Member]
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt, net of offering costs			$ 80,000,000
Debt Instrument, Unused Borrowing Capacity, Amount										80,000,000
Debt Instrument, Periodic Payment, Principal, Percent			1.25%
Repayments of Long-term Debt		3,800,000	$ 3,000,000
Term A-2 Loan [Member] | Sea-Vista [Member]
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt, net of offering costs			$ 120,000,000
Debt Instrument, Unused Borrowing Capacity, Amount										$ 120,000,000
Debt Instrument, Periodic Payment, Principal, Percent			2.50%
Title XI Bonds [Member]
Debt Instrument [Line Items]
Debt Instrument, Repurchase Amount									$ 99,900,000
Debt extinguishment gains (losses), net			$ 29,000,000
Repayments of Long-term Debt				5,900,000
Redemption Premium			20,500,000
Restricted Cash and Cash Equivalents									$ 9,600,000
Other Debt Obligations [Member]
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt, net of offering costs		53,800,000	4,900,000	26,900,000
Repayments of Other Debt		$ 27,500,000	15,900,000	$ 29,500,000
Other Debt Obligations [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt, net of offering costs	$ 3,400,000
Other Debt Obligations [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, stated percentage		2.70%
Other Debt Obligations [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, stated percentage		4.60%
Long-term Debt [Member] | Two Point Five Percentage Convertible Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Repurchase Amount		$ 117,300,000	$ 59,600,000
Hawker Pacific Airservices Limited [Member]
Debt Instrument [Line Items]
Letters of credit outstanding amount		$ 6,500,000

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Tax Credit Carryforward [Line Items]
Cumulative undistributed net earnings of foreign subsidiaries included in retained earnings	$ 7.9
Adjustment to additional paid in capital, income tax effect from share-based compensation, net	2.3	$ 0.1	$ (1.1)
Liability for Uncertain Tax Positions, Noncurrent	11.7			$ 10.1
State and Local Jurisdiction [Member]
Tax Credit Carryforward [Line Items]
State net operating loss carryforwards, valuation allowance	$ 3.6	$ 3.4

Income Taxes (Schedule Of Incom

Income Taxes (Schedule Of Income Before Income Tax Expense (Benefit) And Equity In Earnings Of 50% Or Less Owned Companies) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Contingency [Line Items]
Income Before Income Tax Expense (Benefit) and Equity in Earnings of 50% or Less Owned Companies	$ (262,248)	$ (30,798)	$ 163,235
United States [Member]
Income Tax Contingency [Line Items]
Income Before Income Tax Expense (Benefit) and Equity in Earnings of 50% or Less Owned Companies	(242,375)	(25,441)	160,782
Foreign [Member]
Income Tax Contingency [Line Items]
Income Before Income Tax Expense (Benefit) and Equity in Earnings of 50% or Less Owned Companies	(29,200)	(2,896)	(5,409)
Eliminations And Other [Member]
Income Tax Contingency [Line Items]
Income Before Income Tax Expense (Benefit) and Equity in Earnings of 50% or Less Owned Companies	$ 9,327	$ (2,461)	$ 7,862

Income Taxes (Components Of Inc

Income Taxes (Components Of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
State	$ 5,339	$ 3,155	$ 5,526
Federal	(9,260)	17,442	56,675
Foreign	5,815	5,971	10,060
Current Income Tax Expense, Total	1,894	26,568	72,261
State	(2,568)	(1,875)	196
Federal	(93,246)	(35,539)	(17,222)
Foreign	90	(516)	(38)
Deferred Income Tax Benefit, Total	(95,724)	(37,930)	(17,064)
Income Tax Expense (Benefit)	$ (93,830)	$ (11,362)	$ 55,197

Income Taxes (Schedule Of Effec

Income Taxes (Schedule Of Effective Income Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory rate	(35.00%)	(35.00%)	35.00%
Non-deductible expenses	0.10%	1.70%	0.50%
Noncontrolling interests	(2.60%)	(8.10%)	(5.30%)
Losses of foreign subsidiaries not benefited	1.30%	6.20%	1.20%
State taxes	0.30%	0.60%	2.30%
Other	0.10%	(2.30%)	0.10%
Effective Income Tax Rate	(35.80%)	(36.90%)	33.80%

Income Taxes (Components Of The

Income Taxes (Components Of The Net Deferred Income Tax Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Components of Deferred Tax Assets and Liabilities [Abstract]
Property and Equipment	$ 257,337	$ 302,529
Long-term Debt	46,380	56,110
Unremitted earnings of foreign subsidiaries	24,263	34,977
Investments in 50% or Less Owned Companies	16,549	14,461
Intangible assets	1,908	6,150
Deductible Goodwill	0	4,124
Other	194	990
Total deferred tax liabilities	346,631	419,341
Share award plans	11,078	11,827
Losses on marketable securities	20,746	8,863
Deductible goodwill	1,611	0
Debt and equity issuance costs	7,638	3,029
Other	20,557	8,991
Total deferred tax assets	61,630	32,710
Valuation allowance	3,600	3,357
Net deferred tax assets	58,030	29,353
Net deferred tax liabilities	$ 288,601	$ 389,988

Derivative Instruments And He68

Derivative Instruments And Hedging Strategies (Narrative) (Details) $ in Thousands, € in Millions	12 Months Ended
	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016EUR (€)	Dec. 01, 2015USD ($)
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (10,225)	$ (2,096)	$ (3,902)
Derivative losses on cash flow hedges	(2,537)	(1,304)	(140)
Fair Value Hedging [Member]
Derivative [Line Items]
Derivative, Notional Amount	3,900
Cash Flow Hedging [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 15,800				€ 15
Number of Interest Rate Derivatives Held	2				2
Fixed interest rate	0.03%				0.03%
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (18)	(18)	(176)
MexMar [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 105,500
Number of Interest Rate Derivatives Held	4				4
Fixed interest rate range, start	1.71%				1.71%
Fixed interest rate range, end	2.05%				2.05%
Sea-Cat Crewzer II [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 23,300
Fixed interest rate	1.52%				1.52%
Sea Cat Crewzer [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 20,600
Fixed interest rate	1.52%				1.52%
SeaJon [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 30,300
Fixed interest rate	2.79%				2.79%
Not Designated as Hedging Instrument [Member] | Foreign Exchange [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 3,800
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	200
Not Designated as Hedging Instrument [Member] | OSV Partners [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 38,000
Number of Interest Rate Derivatives Held	0
Fixed interest rate range, start	1.89%				1.89%
Fixed interest rate range, end	2.27%				2.27%
Not Designated as Hedging Instrument [Member] | Dynamic Offshore Drilling Ltd. [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 74,000
Fixed interest rate	1.30%				1.30%
Not Designated as Hedging Instrument [Member] | Falcon Global [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 62,500
Fixed interest rate	2.06%				2.06%
Three Point Seven Five Percentage Convertible Notes [Member]
Derivative [Line Items]
Embedded Derivative, Fair Value of Embedded Derivative Liability						$ 8,500
Embedded Derivative, Gain on Embedded Derivative		2,900	$ 0
Debt Instrument, Interest Rate, Stated Percentage						3.75%
Three Point Seven Five Percentage Convertible Notes [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Embedded Derivative, Fair Value of Embedded Derivative Liability	$ 19,436	$ 5,611
Subsequent Event [Member] | MexMar [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivative, Notional Amount				$ 18,200
Fixed interest rate				2.10%
Construction in Progress [Member]
Derivative [Line Items]
Deferred Gain (Loss) on Discontinuation of Foreign Currency Fair Value Hedge	$ (800)
Minimum [Member] | Not Designated as Hedging Instrument [Member] | Foreign Exchange [Member]
Derivative [Line Items]
Derivative, Term of Contract	12 months
Maximum [Member] | Not Designated as Hedging Instrument [Member] | Foreign Exchange [Member]
Derivative [Line Items]
Derivative, Term of Contract	18 months

Derivative Instruments And He69

Derivative Instruments And Hedging Strategies (Fair Values Of Derivative Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 01, 2015
Derivatives, Fair Value [Line Items]
Derivative Asset	$ 1,237	$ 469
Derivative Liability	20,617	10,896
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0	0
Derivative Liability	389	0
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	1,237	469
Derivative Liability	20,228	10,896
Foreign Exchange [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0	0
Derivative Liability	316	0
Foreign Exchange [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	195	0
Derivative Liability	194	57
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0	0
Derivative Liability	73	0
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0	0
Derivative Liability	0	242
Equity Option [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0
Options On Equities And Equity Indices [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset		0
Derivative Liability	0	4,005
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	1,042	469
Derivative Liability	598	981
Three Point Seven Five Percentage Convertible Notes [Member]
Derivatives, Fair Value [Line Items]
Embedded Derivative, Fair Value of Embedded Derivative Liability			$ 8,500
Three Point Seven Five Percentage Convertible Notes [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Embedded Derivative, Fair Value of Embedded Derivative Asset	0	0
Embedded Derivative, Fair Value of Embedded Derivative Liability	$ 19,436	$ 5,611

Derivative Instruments And He70

Derivative Instruments And Hedging Strategies (Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivative [Line Items]
Derivative gains (losses), net	$ (10,225)	$ (2,096)	$ (3,902)
Equity Option [Member]
Derivative [Line Items]
Derivative gains (losses), net	3,095	(3,200)	38
Foreign Exchange Forward [Member]
Derivative [Line Items]
Derivative gains (losses), net	(378)	(519)	(183)
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative gains (losses), net	(18)	(18)	(176)
Three Point Seven Five Percentage Convertible Notes [Member]
Derivative [Line Items]
Embedded Derivative, Loss on Embedded Derivative	(13,826)
Embedded Derivative, Gain on Embedded Derivative		2,900	0
Exchange Traded [Member] | Commodity Contract [Member]
Derivative [Line Items]
Derivative gains (losses), net	902	(2,744)	(4,250)
Other Trading [Member] | Commodity Contract [Member]
Derivative [Line Items]
Derivative gains (losses), net	$ 0	$ 1,485	$ 669

Fair Value Measurements (Financ

Fair Value Measurements (Financial Assets And Liabilities Measured At Fair Value On Recurring Basis) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Construction Reserve Funds	$ 153,962	$ 255,408
Exchange Option Liability on Subsidiary Convertible Senior Notes	19,436	5,611
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	116,276	138,200
Derivative instruments (included in other receivables)	1,042	469
Construction Reserve Funds	153,962	255,408
Short sales of marketable securities	1,274	4,827
Derivative instruments (included in other current liabilities)	598	4,986
Exchange Option Liability on Subsidiary Convertible Senior Notes	0
Embedded Derivative, Fair Value of Embedded Derivative Liability		0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0	0
Derivative instruments (included in other receivables)	195	0
Construction Reserve Funds	0	0
Short sales of marketable securities	0	0
Derivative instruments (included in other current liabilities)	583	299
Exchange Option Liability on Subsidiary Convertible Senior Notes	0
Embedded Derivative, Fair Value of Embedded Derivative Liability		0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0	0
Derivative instruments (included in other receivables)	0	0
Construction Reserve Funds	0	0
Short sales of marketable securities	0	0
Derivative instruments (included in other current liabilities)	0	0
Exchange Option Liability on Subsidiary Convertible Senior Notes	19,436
Embedded Derivative, Fair Value of Embedded Derivative Liability		5,611
Marketable Security Positions Held By The Company As Of December 31, 2016 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable security gains (losses), net include losses	$ (34,000)	(1,400)	$ 300
Marketable Security Positions Held By The Company As Of December 31, 2015 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable security gains (losses), net include losses		$ 1,500	$ 300

Fair Value Measurements (Estima

Fair Value Measurements (Estimated Fair Value Of Other Financial Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Nov. 13, 2013	Dec. 11, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 399,644		$ 530,009	$ 434,183	$ 527,435
Investment Owned, at Cost	4,432		16,045
Notes, Loans and Financing Receivable, Gross, Noncurrent	12,342		24,587
Debt, Long-term and Short-term, Combined Amount	$ 1,032,373		1,070,390
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%
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, at Carrying Value		$ 403,355
Cash and Cash Equivalents, Fair Value Disclosure	$ 403,355		530,009
Long-term Debt, Fair Value	0		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		0
Long-term Debt, Fair Value	1,062,160		1,043,576
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		0
Long-term Debt, Fair Value	$ 0		$ 0

Fair Value Measurements (Non-Fi

Fair Value Measurements (Non-Financial Assets And Liabilities Measured At Fair Value) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges	$ 130,800,000	$ 7,100,000	$ 4,400,000
Equity Method Investment, Other than Temporary Impairment	14,700,000		$ 3,300,000
Provision for Loan and Lease Losses	8,500,000
Other Offshore Marine Services Joint Ventures [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Method Investment, Other than Temporary Impairment	500,000
Falcon Global [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Method Investment, Other than Temporary Impairment	6,400,000
SCFCo Holdings [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges		21,500,000
Equity Method Investment, Other than Temporary Impairment	$ 7,700,000	21,500,000
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple	7
SeaJon II [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Separately Recognized Transactions, Net Gains and Losses	$ 1,900,000
Offshore Support Vessels [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges	120,800,000	6,600,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Fair Value Disclosure	0
Cost Method Investments, Fair Value Disclosure	0
Equity Method Investments, Fair Value Disclosure	0	102,509,000
Notes Receivable, Fair Value Disclosure	0
Assets Held-for-sale, Long Lived, Fair Value Disclosure		0
Fair Value, Inputs, Level 1 [Member] | Offshore Support Vessels Anchor Handling Towing Supply [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure	0
Fair Value, Inputs, Level 1 [Member] | Liftboats [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure	0
Fair Value, Inputs, Level 1 [Member] | Offshore Support Vessels Specialty [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure	0
Fair Value, Inputs, Level 1 [Member] | Other Property [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Fair Value Disclosure	0
Cost Method Investments, Fair Value Disclosure	3,600,000
Equity Method Investments, Fair Value Disclosure	3,438,000	6,802,000
Notes Receivable, Fair Value Disclosure	0
Assets Held-for-sale, Long Lived, Fair Value Disclosure		200,000
Fair Value, Inputs, Level 2 [Member] | Offshore Support Vessels Anchor Handling Towing Supply [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure	2,600,000
Fair Value, Inputs, Level 2 [Member] | Liftboats [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure	0
Fair Value, Inputs, Level 2 [Member] | Offshore Support Vessels Specialty [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure	4,000,000
Fair Value, Inputs, Level 2 [Member] | Other Property [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure	3,003,000
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Fair Value Disclosure	28,506,000
Cost Method Investments, Fair Value Disclosure	0
Equity Method Investments, Fair Value Disclosure	48,150,000	39,201,000
Notes Receivable, Fair Value Disclosure	11,900,000
Assets Held-for-sale, Long Lived, Fair Value Disclosure		0
Fair Value, Inputs, Level 3 [Member] | Offshore Support Vessels Anchor Handling Towing Supply [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure	$ 42,500,000
Fair Value Inputs, Comparability Adjustments	55.00%
Fair Value Inputs, Discount Rate	74.00%
Fair Value, Inputs, Level 3 [Member] | Liftboats [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure	$ 62,830,000
Fair Value Inputs, Comparability Adjustments	42.00%
Fair Value Inputs, Discount Rate	61.00%
Fair Value, Inputs, Level 3 [Member] | Liftboats [Member] | Falcon Global [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Comparability Adjustments	25.00%
Fair Value, Inputs, Level 3 [Member] | Offshore Support Vessels Specialty [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure	$ 0
Fair Value, Inputs, Level 3 [Member] | Other Property [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure	$ 1,800,000
Fair Value Inputs, Comparability Adjustments	33.00%
Fair Value Inputs, Discount Rate	56.00%
Witt O'Brien's LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Impairment Loss	$ 19,600,000
Corporate And Eliminations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Provision for Loan and Lease Losses	6,700,000
Offshore Marine Services [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges	119,700,000
Goodwill, Impairment Loss		$ 13,400,000
Provision for Loan and Lease Losses	1,800,000
Offshore Marine Services [Member] | Offshore Support Vessels Anchor Handling Towing Supply [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges	62,800,000
Offshore Marine Services [Member] | Offshore Support Vessels [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges	3,600,000
Offshore Marine Services [Member] | Liftboats [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges	19,900,000
Offshore Marine Services [Member] | Offshore Support Vessels Specialty [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges	12,700,000
Finite-Lived Intangible Assets [Member] | Witt O'Brien's LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges	10,000,000
Cost-method Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cost-method Investments, Other than Temporary Impairment	11,600,000
Three Point Seven Five Percentage Convertible Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Embedded Derivative, Loss on Embedded Derivative	13,826,000
Cost Approach Valuation Technique [Member] | Fair Value, Inputs, Level 3 [Member] | Offshore Support Vessels Anchor Handling Towing Supply [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	364,000,000
Cost Approach Valuation Technique [Member] | Fair Value, Inputs, Level 3 [Member] | Liftboats [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 279,000,000

Fair Value Measurements Level 3

Fair Value Measurements Level 3 Inputs (Details) - Fair Value, Inputs, Level 3 [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Share Price	$ 71.28	$ 50
Fair Value Assumptions, Risk Free Interest Rate	2.08%	2.08%
Fair Value Assumptions, Expected Volatility Rate	30.80%	24.80%
Fair Value Inputs, Entity Credit Risk	5.63%	8.26%

Common Stock (Details)

Common Stock (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Nov. 15, 2016
Equity, Class of Treasury Stock [Line Items]
Treasury stock, shares acquired		1,162,955	2,531,324
Treasury Stock, Value, Acquired, Cost Method		$ 72.4	$ 195.3
Stock Repurchase Program, Authorized Amount				$ 150
Repurchase program, remaining authorized repurchase amount	$ 147
Restricted Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Treasury stock, shares acquired	47,455	40,859
Treasury Stock, Value, Acquired, Cost Method	$ 2.4	$ 3
Employee Stock Option [Member]
Equity, Class of Treasury Stock [Line Items]
Treasury stock, shares acquired			26,792
Treasury Stock, Value, Acquired, Cost Method			$ 2

Noncontrolling Interests in S76

Noncontrolling Interests in Subsidiaries (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016USD ($)equipment	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2016USD ($)equipment	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Noncontrolling Interest [Line Items]
Noncontrolling interests in subsidiaries	$ 135,376				$ 120,119				$ 135,376	$ 120,119
Net Income (Loss)	(90,289)	$ (34,026)	$ (50,933)	$ (20,524)	(49,853)	$ 16,405	$ (8,501)	$ (17,901)	(195,772)	(59,850)	$ 124,347
Net Income (Loss) Attributable to Noncontrolling Interest									20,125	8,932	24,215
Noncontrolling Interest, Increase from Subsidiary Equity Issuance										400	152,423
Purchase of subsidiary shares from noncontrolling interests										(497)	3,110
Dividends paid to noncontrolling interests									3,753	5,199	6,070
Windcat Workboats Ltd. [Member]
Noncontrolling Interest [Line Items]
Net Assets					29,900					29,900
Illinois Corn Processing Llc [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interests in subsidiaries					22,272					22,272
Net Assets					74,200					74,200
Net Income (Loss)											38,400
Net Income (Loss) Attributable to Noncontrolling Interest											10,300
Offshore Marine Services [Member] | Windcat Workboats Ltd. [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interests in subsidiaries	5,266				7,484				5,266	7,484
Net Assets	$ 21,100								21,100
Net Income (Loss)									(4,500)	1,600	1,900
Net Income (Loss) Attributable to Noncontrolling Interest									$ (1,100)	400	500
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	25.00%								25.00%
Offshore Marine Services [Member] | Other Offshore Marine Services Noncontrolling Interests [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interests in subsidiaries	$ 277				470				$ 277	470
Inland River Services [Member]
Noncontrolling Interest [Line Items]
Purchase of subsidiary shares from noncontrolling interests											1,000
Payments for Repurchase of Redeemable Noncontrolling Interest											3,100
Dividends paid to noncontrolling interests											2,100
Inland River Services [Member] | Other Inland River Services Noncontrolling Interests [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interests in subsidiaries	980				1,146				980	1,146
Shipping Services [Member] | Sea-Vista [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interests in subsidiaries	106,054				88,290				106,054	88,290
Net Assets	$ 216,400				180,200				216,400	180,200
Net Income (Loss)									36,300	5,200	25,100
Net Income (Loss) Attributable to Noncontrolling Interest									$ 17,800	2,600	$ 12,300
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	49.00%								49.00%		49.00%
Noncontrolling Interest, Increase from Subsidiary Equity Issuance											$ 145,700
Payments of Stock Issuance Costs											$ 3,200
Illinois Corn Processing Llc [Member] | Illinois Corn Processing Llc [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interests in subsidiaries	$ 22,647								$ 22,647
Net Assets		$ 75,500
Net Income (Loss)									12,300	19,500
Net Income (Loss) Attributable to Noncontrolling Interest									$ 3,700	5,900
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	30.00%								30.00%
Other Segments [Member] | Other Noncontrolling Interests [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interests in subsidiaries	$ 152				$ 457				$ 152	$ 457
U.S.-flag Product Tankers [Member]
Noncontrolling Interest [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	1								1
U.S.-flag Product Tankers [Member] | Shipping Services [Member] | Sea-Vista [Member]
Noncontrolling Interest [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	1								1
Minimum [Member] | Offshore Marine Services [Member] | Other Offshore Marine Services Noncontrolling Interests [Member]
Noncontrolling Interest [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	1.80%								1.80%
Minimum [Member] | Inland River Services [Member] | Other Inland River Services Noncontrolling Interests [Member]
Noncontrolling Interest [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	3.00%								3.00%
Minimum [Member] | Other Segments [Member] | Other Noncontrolling Interests [Member]
Noncontrolling Interest [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	5.00%								5.00%
Maximum [Member] | Offshore Marine Services [Member] | Other Offshore Marine Services Noncontrolling Interests [Member]
Noncontrolling Interest [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	30.00%								30.00%
Maximum [Member] | Inland River Services [Member] | Other Inland River Services Noncontrolling Interests [Member]
Noncontrolling Interest [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	51.80%								51.80%
Maximum [Member] | Other Segments [Member] | Other Noncontrolling Interests [Member]
Noncontrolling Interest [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	14.60%								14.60%

Savings Plans And Multiemploy77

Savings Plans And Multiemployer Pension Plans (Details) £ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2015GBP (£)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2012USD ($)	Sep. 30, 2014USD ($)	Mar. 31, 2014USD ($)	Mar. 31, 2014GBP (£)
United Kingdom Merchant Navy Officers Pension Fund [Member] | Foreign Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Pension and other postretirement benefit expense					$ 19.4
United Kingdom Merchant Navy Ratings Pension Fund [Member] | Foreign Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Pension and other postretirement benefit expense		$ 6.9	£ 4.5			$ 0.4
Pension and other postretirement benefit plans, total funding deficit								$ 491.7	£ 325
American Maritime Officers Pension Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Multiemployer Plans, Withdrawal Obligation							$ 39.9
Pension and Other Postretirement Benefit Contributions	$ 1.4	1.1		$ 1.1
Seafarers Pension Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefit Contributions	$ 1.9	1.6		1.5
SEACOR Deferred Compensation Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	75.00%
Deferred compensation obligation	$ 0.4	0.3
SEACOR Deferred Compensation Plan [Member] | Deferred Bonus [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	100.00%
SEACOR Deferred Compensation Plan [Member] | Restricted Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	100.00%
SEACOR Savings Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer Matching Contribution Percent of Employees' Gross Pay	3.50%
Defined Contribution Plan Contributions	$ 1.8	3.8		2.4
Other Defined Contribution Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan Contributions	$ 0.7	$ 0.7		$ 0.7

Share Based Compensation (Narra

Share Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized for grant under the Share Incentive Plans	6,650,000
Exercise price per share of options granted, percentage, minimum	100.00%
Additional compensation expense	$ 14.1	$ 14.9	$ 15.3
Unrecognized compensation costs	26.7
Compensation costs expected to be recognized in 2017	11
Compensation costs expected to be recognized in 2018	$ 8.3
Weighted average values of grants	$ 31.31	$ 41.09	$ 53.03
Weighted average expected volatility	26.50%	25.16%	29.40%
Weighted average discount rates	1.59%	1.79%	1.85%
Expected lives	6 years 3 months	6 years 11 days	5 years 11 months 1 day
Total grant date fair value of restricted stock and restricted stock units vested	$ 10.8	$ 10.8	$ 3.7
Aggregate intrinsic value of exercised stock options	$ 1.4	$ 1	$ 5.1
Weighted average remaining contractual term for total outstanding stock options	5 years 51 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	3 years 292 days
Aggregate intrinsic value of options outstanding	$ 17.2
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 13.5
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized for grant under the Share Incentive Plans	600,000
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date	85.00%
Common stock made available for purchase under the Employee Stock Purchase Plans, offering period, months	6
Restricted Stock [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units vesting period	1 year
Restricted Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units vesting period	5 years
Employee Stock Option [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units vesting period	1 year
Employee Stock Option [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units vesting period	5 years

Share Based Compensation (Share

Share Based Compensation (Share Based Compensation Plans) (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards granted	137,258	135,150	150,145
Restricted stock awards forfeited	(2,867)	0	(1,325)
Restricted Stock Unit, Converted to shares and issued to Deferred Compensation Plan	0	217	216
Stock Option, Outstanding as of December 31,	1,639,865	1,690,899	1,546,508	1,481,280
Total Options, Granted, Number of Shares	197,550	192,350	199,100
Stock Options, Exercised, Number of Shares	113,820	40,461	133,872
Stock Options, Forfeited, Number of Shares	18,760	0	0
Stock Options, Expired, Number of Shares	116,004	7,498	0
Stock Issued During Period, Shares, Employee Stock Purchase Plans	41,924	39,384	30,622
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	522,341	764,567	1,127,328
Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Director stock awards granted	3,125	3,375	2,625

Share Based Compensation (Sched

Share Based Compensation (Schedule Of Share-based Compensation, Restricted Stock And Restricted Stock Units Activity) (Details) - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested as of December 31	380,812	387,878
Granted	137,258
Vested	(141,457)
Forfeited	2,867
Weighted Average Grant Price Nonvested	$ 67.92	$ 76.93
Granted Weighted Average Grant Price	51.1
Vested Weighted Average Grant Price	76.37
Forfeited Weighted Average Grant Price	$ 64.49

Share Based Compensation (Sch81

Share Based Compensation (Schedule Of Share-based Compensation, Stock Options, Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Option, Outstanding as of December 31,	1,639,865	1,690,899	1,546,508	1,481,280
Stock Options, Granted, Number of Shares	197,550
Stock Options, Vested, Number of Shares	0
Stock Options, Exercised, Number of Shares	113,820	40,461	133,872
Stock Options, Forfeited, Number of Shares	18,760	0	0
Stock Options, Expired, Number of Shares	116,004	7,498	0
Stock Options Weighted Average Exercise Price Outstanding	$ 63.09	$ 62.70
Stock Options, Granted, Weighted Average Exercise Price	57.52
Stock Options, Vested, Weighted Average Exercise Price	0
Stock Options, Exercised, Weighted Average Exercise Price	48.58
Stock Options, Forfeited, Weighted Average Exercise Price	71.90
Stock Options. Expired, Weighted Average Exercise Price	$ 60.85
Nonvested Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Option, Outstanding as of December 31,	530,472	571,224
Stock Options, Granted, Number of Shares	197,550
Stock Options, Vested, Number of Shares	219,542
Stock Options, Exercised, Number of Shares	0
Stock Options, Forfeited, Number of Shares	18,760
Stock Options, Expired, Number of Shares	0
Stock Options Weighted Average Exercise Price Outstanding	$ 20.63	$ 22.83
Stock Options, Granted, Weighted Average Exercise Price	17.09
Stock Options, Vested, Weighted Average Exercise Price	22.98
Stock Options, Exercised, Weighted Average Exercise Price	0
Stock Options, Forfeited, Weighted Average Exercise Price	22.72
Stock Options. Expired, Weighted Average Exercise Price	$ 0
Vested Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Option, Outstanding as of December 31,	1,109,393	1,119,675
Stock Options, Granted, Number of Shares	0
Stock Options, Vested, Number of Shares	219,542
Stock Options, Exercised, Number of Shares	113,820
Stock Options, Forfeited, Number of Shares	0
Stock Options, Expired, Number of Shares	116,004
Stock Options Weighted Average Exercise Price Outstanding	$ 61.03	$ 57.64
Stock Options, Granted, Weighted Average Exercise Price	0
Stock Options, Vested, Weighted Average Exercise Price	71.76
Stock Options, Exercised, Weighted Average Exercise Price	48.58
Stock Options, Forfeited, Weighted Average Exercise Price	0
Stock Options. Expired, Weighted Average Exercise Price	$ 60.85

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OSV Partners [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Revenues from Transactions with Related Party	$ 0.5	$ 1.2	$ 1.2
Partners' Capital Account, Contributions	$ 1.2	1.4	5.1
Equity Method Investment, Ownership Percentage	30.40%
Officer [Member] | OSV Partners [Member]
Related Party Transaction [Line Items]
Partners' Capital Account, Contributions		0.2
Equity Method Investment, Ownership Percentage	1.74%
Diamond Offshore Drilling, Inc. [Member] | Maximum [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Revenues from Transactions with Related Party	$ 5
Era Group [Member] | Maximum [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Revenues from Transactions with Related Party	5
Dry-cargo barge pools [Member] | President [Member]
Related Party Transaction [Line Items]
Related party transaction, amounts	0.8	1.3	1.7
Management fees	0.1	0.1	0.2
Payables to related parties	0.5	0.6
Illinois Corn Processing Llc [Member] | MGP Ingredients, Inc. [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Revenues from Transactions with Related Party	27.7	38.9	$ 36.3
Due from Related Parties, Current	$ 3.4	$ 2.4

Commitments And Contingencies (

Commitments And Contingencies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2016USD ($)equipment	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013claim	Dec. 31, 2012claim	Dec. 31, 2010claim	Sep. 30, 2016equipment	Mar. 31, 2016USD ($)equipment
Commitments and Contingencies [Line Items]
Unrecorded unconditional purchase obligation	$ 182,435,000							$ 800,000
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	116,482,000
Unrecorded Unconditional Purchase Obligation, Due within Two Years	50,930,000
Unrecorded Unconditional Purchase Obligation, Due within Three Years	13,223,000
Gain (Loss) Related to Litigation Settlement			$ 14,700,000
Total rental expense for operating leases	54,600,000	$ 59,900,000	$ 66,800,000
Unrecorded Unconditional Purchase Obligation, Due in Rolling Year Four	$ 1,800,000
Offshore Support Vessels Fast Support [Member]
Commitments and Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	9
Offshore Support Vessels Supply [Member]
Commitments and Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity	0
Wind Farm Utility Vessel [Member]
Commitments and Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	1
U.S.-flag Product Tankers [Member]
Commitments and Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	1
Number of equipment leases | equipment	3
Sale Leaseback Transaction, Lease Terms	76
U.S. Flag Articulated Tug-Barge [Member]
Commitments and Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	1
U.S.-flag Harbor Tugs [Member]
Commitments and Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	3
Number of equipment leases | equipment	9
Foreign-flag Harbor Tugs [Member]
Commitments and Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment	2
Inland River Liquid Tank Barges - 30,000 Barrel [Member]
Commitments and Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment								1
Inland River Towboats [Member]
Commitments and Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Maximum Quantity | equipment							3
Number of equipment leases | equipment	4
Inland River Harbor Boats [Member]
Commitments and Contingencies [Line Items]
Number of equipment leases | equipment	6
Offshore Support Vessels [Member]
Commitments and Contingencies [Line Items]
Number of equipment leases | equipment	8
Minimum [Member]
Commitments and Contingencies [Line Items]
Sale Leaseback Transaction, Lease Terms			10
Lessee Leasing Arrangements, Operating Leases, Term of Contract	1 month
Minimum [Member] | U.S.-flag Product Tankers [Member]
Commitments and Contingencies [Line Items]
Sale Leaseback Transaction, Lease Terms	69
Maximum [Member]
Commitments and Contingencies [Line Items]
Sale Leaseback Transaction, Lease Terms		84	84
Lessee Leasing Arrangements, Operating Leases, Term of Contract	17 years
Maximum [Member] | U.S.-flag Product Tankers [Member]
Commitments and Contingencies [Line Items]
Sale Leaseback Transaction, Lease Terms	85
Multi-district Litigation [Member]
Commitments and Contingencies [Line Items]
Loss Contingency, New Claims Filed, Number | claim						1
Loss Contingency, Number of Plaintiffs	11
Abney Litigation [Member]
Commitments and Contingencies [Line Items]
Loss Contingency, New Claims Filed, Number | claim					668
Abood Litigation [Member]
Commitments and Contingencies [Line Items]
Loss Contingency, New Claims Filed, Number | claim				174
Offshore Marine Services [Member]
Commitments and Contingencies [Line Items]
Unrecorded unconditional purchase obligation	$ 94,850,000
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	29,272,000
Unrecorded Unconditional Purchase Obligation, Due within Two Years	50,555,000
Unrecorded Unconditional Purchase Obligation, Due within Three Years	13,223,000
Unrecorded Unconditional Purchase Obligation, Due within Four Years		$ 1,800,000
Offshore Marine Services [Member] | Offshore Support Vessels Supply [Member]
Commitments and Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Contingent Upon a Third Party Option	$ 15,400,000
Unrecorded Unconditional Purchase Obligation, Contingent Upon a Third Party Option, Maximum Quantity	1
Shipping Services [Member]
Commitments and Contingencies [Line Items]
Unrecorded unconditional purchase obligation	$ 55,430,000
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	55,430,000
Unrecorded Unconditional Purchase Obligation, Due within Two Years	0
Unrecorded Unconditional Purchase Obligation, Due within Three Years	0
Unrecorded Unconditional Purchase Obligation, Due within Four Years	0
Inland River Services [Member]
Commitments and Contingencies [Line Items]
Unrecorded unconditional purchase obligation	30,102,000
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	30,102,000
Unrecorded Unconditional Purchase Obligation, Due within Two Years	0
Unrecorded Unconditional Purchase Obligation, Due within Three Years	0
Unrecorded Unconditional Purchase Obligation, Due within Four Years	0
Illinois Corn Processing Llc [Member]
Commitments and Contingencies [Line Items]
Unrecorded unconditional purchase obligation	2,053,000
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year	1,678,000
Unrecorded Unconditional Purchase Obligation, Due within Two Years	375,000
Unrecorded Unconditional Purchase Obligation, Due within Three Years	0
Unrecorded Unconditional Purchase Obligation, Due within Four Years	$ 0
Other Income [Member]
Commitments and Contingencies [Line Items]
Gain (Loss) Related to Litigation Settlement			$ 14,700,000

Commitments And Contingencies84

Commitments And Contingencies (Future Minimum Payments Under Operating Leases) (Details) $ in Thousands	Dec. 31, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
Total Minimum Payments, 2017	$ 59,014
Total Minimum Payments, 2018	58,772
Total Minimum Payments, 2019	43,836
Total Minimum Payments, 2020	38,570
Total Minimum Payments, 2021	28,386
Total Minimum Payments, Years subsequent to 2021	31,267
Non-cancelable Subleases, 2017	17,345
Non-cancelable Subleases, 2018	17,345
Non-cancelable Subleases, 2012	17,345
Non-cancelable Subleases, 2020	17,392
Non-cancelable Subleases, 2021	17,345
Non-cancelable Subleases, Years subsequent to 2021	24,045
Net Minimum Payments, 2017	41,669
Net Minimum Payments, 2018	41,427
Net Minimum Payments, 2019	26,491
Net Minimum Payments, 2020	21,178
Net Minimum Payments, 2021	11,041
Net Minimum Payments, Years subsequent to 2021	$ 7,222

Major Customers And Segment I85

Major Customers And Segment Information (Operating Results, Capital Expenditures And Assets By Reportable Segments) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Operating Revenues	$ (213,036,000)	$ (206,983,000)	$ (197,038,000)	$ (213,928,000)	$ (250,631,000)	$ (261,852,000)	$ (281,609,000)	$ (260,644,000)	$ (830,985,000)	$ (1,054,736,000)	$ (1,319,394,000)
Administrative and general									138,581,000	156,611,000	164,938,000
Depreciation and amortization									124,933,000	125,987,000	131,819,000
Total costs and expenses									861,327,000	1,031,203,000	1,206,129,000
Gains (Losses) on Asset Dispositions and Impairments, Net									(142,205,000)	(2,408,000)	51,978,000
Operating Income (Loss)	(99,364,000)	$ (33,016,000)	$ (30,151,000)	$ (10,016,000)	(928,000)	$ 28,221,000	$ 7,499,000	$ (13,667,000)	(172,547,000)	21,125,000	165,243,000
Derivative gains (losses), net									(10,225,000)	(2,096,000)	(3,902,000)
Foreign currency gains (losses), net									(1,868,000)	(4,752,000)	(6,335,000)
Other, net									(20,206,000)	6,773,000	3,439,000
Income (Loss) from Equity Method Investments									(27,354,000)	(40,414,000)	16,309,000
Income Before Income Tax Expense (Benefit) and Equity in Earnings of 50% or Less Owned Companies									(262,248,000)	(30,798,000)	163,235,000
Payments to Acquire Property, Plant, and Equipment									358,413,000	295,930,000	360,637,000
Property, Plant and Equipment, Gross	2,194,023,000				2,123,201,000				2,194,023,000	2,123,201,000
Accumulated depreciation	(1,008,867,000)				(994,181,000)				(1,008,867,000)	(994,181,000)
Construction in progress	370,512,000				454,605,000				370,512,000	454,605,000
Net property and equipment	1,555,668,000				1,583,625,000				1,555,668,000	1,583,625,000	1,502,673,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	313,772,000				331,103,000				313,772,000	331,103,000
Inventories	16,773,000				24,768,000				16,773,000	24,768,000
Goodwill	32,758,000				52,340,000				32,758,000	52,340,000
Intangible Assets	20,078,000				26,392,000				20,078,000	26,392,000
Total Assets	2,862,321,000				3,185,419,000				2,862,321,000	3,185,419,000	3,234,373,000
Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(215,536,000)	(368,744,000)	(529,761,000)
Property, Plant and Equipment, Gross	958,759,000				1,102,619,000				958,759,000	1,102,619,000
Net property and equipment	418,140,000				555,657,000				418,140,000	555,657,000
Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(165,140,000)	(227,601,000)	(249,288,000)
Property, Plant and Equipment, Gross	419,714,000				485,144,000				419,714,000	485,144,000
Net property and equipment	252,587,000				313,873,000				252,587,000	313,873,000
Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(229,643,000)	(227,142,000)	(214,316,000)
Property, Plant and Equipment, Gross	727,602,000				454,144,000				727,602,000	454,144,000
Net property and equipment	469,598,000				215,068,000				469,598,000	215,068,000
Illinois Corn Processing Llc [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(177,401,000)	(166,905,000)	(236,293,000)
Property, Plant and Equipment, Gross	56,708,000				47,256,000				56,708,000	47,256,000
Net property and equipment	33,019,000				27,866,000				33,019,000	27,866,000
Sales Revenue, Goods, Net									167,000,000	154,800,000	224,400,000
Cost of Goods Sold									148,200,000	131,900,000	175,800,000
Inventory, Raw Materials	1,800,000				2,100,000				1,800,000	2,100,000	2,200,000
Inventory, Work in Process	1,500,000				1,500,000				1,500,000	1,500,000	1,700,000
Witt O'Brien's LLC [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(42,783,000)	(49,838,000)	(27,691,000)
Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(482,000)	(14,506,000)	(62,045,000)
Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues									0	0	0
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(830,985,000)	(1,054,736,000)	(1,319,394,000)
Operating Expenses									597,813,000	748,605,000	909,372,000
Administrative and general									138,581,000	156,611,000	164,938,000
Depreciation and amortization									124,933,000	125,987,000	131,819,000
Total costs and expenses									861,327,000	1,031,203,000	1,206,129,000
Gains (Losses) on Asset Dispositions and Impairments, Net									(142,205,000)	(2,408,000)	51,978,000
Operating Income (Loss)									(172,547,000)	21,125,000	165,243,000
Derivative gains (losses), net									(10,225,000)	(2,096,000)	(3,902,000)
Foreign currency gains (losses), net									(1,868,000)	(4,752,000)	(6,335,000)
Other, net									(20,206,000)	6,773,000	3,439,000
Income (Loss) from Equity Method Investments									(27,354,000)	(40,414,000)	16,309,000
Payments to Acquire Property, Plant, and Equipment									358,413,000	295,930,000	360,637,000
Property, Plant and Equipment, Gross	2,194,023,000				2,123,201,000				2,194,023,000	2,123,201,000	2,086,957,000
Accumulated depreciation	(1,008,867,000)				(994,181,000)				(1,008,867,000)	(994,181,000)	(902,284,000)
Property, Plant and Equipment, Net In Service	1,185,156,000				1,129,020,000				1,185,156,000	1,129,020,000	1,184,673,000
Construction in progress	370,512,000				454,605,000				370,512,000	454,605,000	318,000,000
Net property and equipment	1,555,668,000				1,583,625,000				1,555,668,000	1,583,625,000	1,502,673,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	313,772,000				331,103,000				313,772,000	331,103,000	484,157,000
Inventories	16,773,000				24,768,000				16,773,000	24,768,000	22,783,000
Goodwill	32,758,000				52,340,000				32,758,000	52,340,000	62,759,000
Intangible Assets	20,078,000				26,392,000				20,078,000	26,392,000	32,727,000
Other current and long-term assets, excluding cash and near cash assets	249,679,000				243,574,000				249,679,000	243,574,000	342,630,000
Operating Segments [Member] | Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(215,636,000)	(368,868,000)	(529,944,000)
Operating Expenses									166,925,000	275,972,000	365,092,000
Administrative and general									49,308,000	53,085,000	58,353,000
Depreciation and amortization									58,069,000	61,729,000	64,615,000
Total costs and expenses									274,302,000	390,786,000	488,060,000
Gains (Losses) on Asset Dispositions and Impairments, Net									(116,222,000)	(17,017,000)	26,545,000
Operating Income (Loss)									(174,888,000)	(38,935,000)	68,429,000
Derivative gains (losses), net									2,995,000	(2,766,000)	(171,000)
Foreign currency gains (losses), net									(3,312,000)	(27,000)	(1,375,000)
Other, net									(1,490,000)	261,000	14,671,000
Income (Loss) from Equity Method Investments									(6,314,000)	8,757,000	10,468,000
Segment Profit (Loss)									(183,009,000)	(32,710,000)	92,022,000
Payments to Acquire Property, Plant, and Equipment									100,884,000	87,765,000	83,513,000
Property, Plant and Equipment, Gross	958,759,000				1,102,619,000				958,759,000	1,102,619,000	1,060,986,000
Accumulated depreciation	(540,619,000)				(546,962,000)				(540,619,000)	(546,962,000)	(500,007,000)
Property, Plant and Equipment, Net In Service	418,140,000				555,657,000				418,140,000	555,657,000	560,979,000
Construction in progress	123,801,000				97,900,000				123,801,000	97,900,000	87,935,000
Net property and equipment	541,941,000				653,557,000				541,941,000	653,557,000	648,914,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	138,311,000				130,010,000				138,311,000	130,010,000	115,436,000
Inventories	3,058,000				4,000,000				3,058,000	4,000,000	5,570,000
Goodwill	0				0				0	0	13,367,000
Intangible Assets	0				1,049,000				0	1,049,000	1,917,000
Other current and long-term assets, excluding cash and near cash assets	72,810,000				97,488,000				72,810,000	97,488,000	128,499,000
Total Assets	756,120,000				886,104,000				756,120,000	886,104,000	913,703,000
Operating Segments [Member] | Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(167,543,000)	(230,482,000)	(253,150,000)
Operating Expenses									124,460,000	168,015,000	174,918,000
Administrative and general									14,616,000	15,567,000	15,937,000
Depreciation and amortization									26,327,000	28,632,000	29,435,000
Total costs and expenses									165,403,000	212,214,000	220,290,000
Gains (Losses) on Asset Dispositions and Impairments, Net									3,193,000	14,868,000	29,657,000
Operating Income (Loss)									5,333,000	33,136,000	62,517,000
Derivative gains (losses), net									0	294,000	0
Foreign currency gains (losses), net									1,722,000	(3,726,000)	(3,335,000)
Other, net									(4,000)	0	(38,000)
Income (Loss) from Equity Method Investments									(15,944,000)	(31,200,000)	6,673,000
Segment Profit (Loss)									(8,893,000)	(1,496,000)	65,817,000
Payments to Acquire Property, Plant, and Equipment									36,803,000	69,736,000	58,481,000
Property, Plant and Equipment, Gross	419,714,000				485,144,000				419,714,000	485,144,000	491,079,000
Accumulated depreciation	(167,127,000)				(171,271,000)				(167,127,000)	(171,271,000)	(159,532,000)
Property, Plant and Equipment, Net In Service	252,587,000				313,873,000				252,587,000	313,873,000	331,547,000
Construction in progress	13,003,000				17,807,000				13,003,000	17,807,000	27,415,000
Net property and equipment	265,590,000				331,680,000				265,590,000	331,680,000	358,962,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	69,181,000				81,363,000				69,181,000	81,363,000	103,688,000
Inventories	1,602,000				1,493,000				1,602,000	1,493,000	2,536,000
Goodwill	2,400,000				2,364,000				2,400,000	2,364,000	2,573,000
Intangible Assets	12,018,000				5,961,000				12,018,000	5,961,000	6,483,000
Other current and long-term assets, excluding cash and near cash assets	88,165,000				72,180,000				88,165,000	72,180,000	99,335,000
Total Assets	438,956,000				495,041,000				438,956,000	495,041,000	573,577,000
Operating Segments [Member] | Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(229,643,000)	(227,142,000)	(214,316,000)
Operating Expenses									122,631,000	129,039,000	112,771,000
Administrative and general									27,825,000	26,215,000	24,518,000
Depreciation and amortization									31,162,000	26,296,000	28,420,000
Total costs and expenses									181,618,000	181,550,000	165,709,000
Gains (Losses) on Asset Dispositions and Impairments, Net									411,000	0	159,000
Operating Income (Loss)									48,436,000	45,592,000	48,766,000
Derivative gains (losses), net									0	0	0
Foreign currency gains (losses), net									(18,000)	(30,000)	(40,000)
Other, net									(6,224,000)	2,053,000	(3,630,000)
Income (Loss) from Equity Method Investments									(4,697,000)	(18,782,000)	(661,000)
Segment Profit (Loss)									37,497,000	28,833,000	44,435,000
Payments to Acquire Property, Plant, and Equipment									215,837,000	134,581,000	199,602,000
Property, Plant and Equipment, Gross	727,602,000				454,144,000				727,602,000	454,144,000	453,862,000
Accumulated depreciation	(258,004,000)				(239,076,000)				(258,004,000)	(239,076,000)	(213,072,000)
Property, Plant and Equipment, Net In Service	469,598,000				215,068,000				469,598,000	215,068,000	240,790,000
Construction in progress	233,214,000				335,113,000				233,214,000	335,113,000	201,554,000
Net property and equipment	702,812,000				550,181,000				702,812,000	550,181,000	442,344,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	51,620,000				64,499,000				51,620,000	64,499,000	222,420,000
Inventories	843,000				701,000				843,000	701,000	1,030,000
Goodwill	1,852,000				1,852,000				1,852,000	1,852,000	1,852,000
Intangible Assets	0				0				0	0	292,000
Other current and long-term assets, excluding cash and near cash assets	29,801,000				28,359,000				29,801,000	28,359,000	23,910,000
Total Assets	786,928,000				645,592,000				786,928,000	645,592,000	691,848,000
Operating Segments [Member] | Illinois Corn Processing Llc [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(177,401,000)	(166,905,000)	(236,293,000)
Operating Expenses									158,495,000	143,967,000	187,849,000
Administrative and general									3,011,000	2,307,000	2,177,000
Depreciation and amortization									4,299,000	3,902,000	4,119,000
Total costs and expenses									165,805,000	150,176,000	194,145,000
Gains (Losses) on Asset Dispositions and Impairments, Net									0	0	0
Operating Income (Loss)									11,596,000	16,729,000	42,148,000
Derivative gains (losses), net									911,000	(1,251,000)	(3,777,000)
Foreign currency gains (losses), net									0	0	0
Other, net									0	4,112,000	660,000
Income (Loss) from Equity Method Investments									0	0	0
Segment Profit (Loss)									12,507,000	19,590,000	39,031,000
Payments to Acquire Property, Plant, and Equipment									4,723,000	4,712,000	3,108,000
Property, Plant and Equipment, Gross	56,708,000				47,256,000				56,708,000	47,256,000	47,256,000
Accumulated depreciation	(23,689,000)				(19,390,000)				(23,689,000)	(19,390,000)	(15,488,000)
Property, Plant and Equipment, Net In Service	33,019,000				27,866,000				33,019,000	27,866,000	31,768,000
Construction in progress	701,000				5,430,000				701,000	5,430,000	718,000
Net property and equipment	33,720,000				33,296,000				33,720,000	33,296,000	32,486,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	0				0				0	0	0
Inventories	11,133,000				18,574,000				11,133,000	18,574,000	11,170,000
Goodwill	0				0				0	0	0
Intangible Assets	0				0				0	0	0
Other current and long-term assets, excluding cash and near cash assets	11,850,000				7,739,000				11,850,000	7,739,000	11,538,000
Total Assets	56,703,000				59,609,000				56,703,000	59,609,000	55,194,000
Operating Segments [Member] | Witt O'Brien's LLC [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(42,916,000)	(49,984,000)	(27,691,000)
Operating Expenses									28,561,000	21,899,000	12,978,000
Administrative and general									16,214,000	24,096,000	19,180,000
Depreciation and amortization									1,539,000	1,711,000	1,045,000
Total costs and expenses									46,314,000	47,706,000	33,203,000
Gains (Losses) on Asset Dispositions and Impairments, Net									(29,587,000)	(27,000)	0
Operating Income (Loss)									(32,985,000)	2,251,000	(5,512,000)
Derivative gains (losses), net									0	0	0
Foreign currency gains (losses), net									(181,000)	(36,000)	(53,000)
Other, net									0	19,000	(5,056,000)
Income (Loss) from Equity Method Investments									305,000	135,000	(465,000)
Segment Profit (Loss)									(32,861,000)	2,369,000	(11,086,000)
Payments to Acquire Property, Plant, and Equipment									2,000	409,000	0
Property, Plant and Equipment, Gross	1,559,000				3,338,000				1,559,000	3,338,000	3,342,000
Accumulated depreciation	(1,244,000)				(2,834,000)				(1,244,000)	(2,834,000)	(3,002,000)
Property, Plant and Equipment, Net In Service	315,000				504,000				315,000	504,000	340,000
Construction in progress	0				0				0	0	0
Net property and equipment	315,000				504,000				315,000	504,000	340,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	566,000				344,000				566,000	344,000	524,000
Inventories	137,000				0				137,000	0	0
Goodwill	28,506,000				48,124,000				28,506,000	48,124,000	44,967,000
Intangible Assets	8,060,000				19,382,000				8,060,000	19,382,000	24,035,000
Other current and long-term assets, excluding cash and near cash assets	14,284,000				14,780,000				14,284,000	14,780,000	26,131,000
Total Assets	51,868,000				83,134,000				51,868,000	83,134,000	95,997,000
Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(482,000)	(14,506,000)	(62,045,000)
Operating Expenses									0	13,054,000	59,666,000
Administrative and general									1,001,000	2,546,000	5,957,000
Depreciation and amortization									0	5,000	284,000
Total costs and expenses									1,001,000	15,605,000	65,907,000
Gains (Losses) on Asset Dispositions and Impairments, Net									0	(232,000)	(1,077,000)
Operating Income (Loss)									(519,000)	(1,331,000)	(4,939,000)
Derivative gains (losses), net									0	(472,000)	270,000
Foreign currency gains (losses), net									(1,000)	(11,000)	(102,000)
Other, net									(12,608,000)	33,000	(3,097,000)
Income (Loss) from Equity Method Investments									(704,000)	676,000	294,000
Segment Profit (Loss)									(13,832,000)	(1,105,000)	(7,574,000)
Payments to Acquire Property, Plant, and Equipment									0	0	148,000
Property, Plant and Equipment, Gross	0				0				0	0	271,000
Accumulated depreciation	0				0				0	0	(247,000)
Property, Plant and Equipment, Net In Service	0				0				0	0	24,000
Construction in progress	0				0				0	0	234,000
Net property and equipment	0				0				0	0	258,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	54,094,000				54,887,000				54,094,000	54,887,000	42,089,000
Inventories	0				0				0	0	2,477,000
Goodwill	0				0				0	0	0
Intangible Assets	0				0				0	0	0
Other current and long-term assets, excluding cash and near cash assets	11,193,000				16,014,000				11,193,000	16,014,000	45,547,000
Total Assets	65,287,000				70,901,000				65,287,000	70,901,000	90,371,000
Operating Segments [Member] | Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues									2,636,000	3,151,000	4,045,000
Operating Expenses									(3,259,000)	(3,341,000)	(3,902,000)
Administrative and general									26,606,000	32,795,000	38,816,000
Depreciation and amortization									3,537,000	3,712,000	3,901,000
Total costs and expenses									26,884,000	33,166,000	38,815,000
Gains (Losses) on Asset Dispositions and Impairments, Net									0	0	(3,306,000)
Operating Income (Loss)									(29,520,000)	(36,317,000)	(46,166,000)
Derivative gains (losses), net									(14,131,000)	2,099,000	(224,000)
Foreign currency gains (losses), net									(78,000)	(922,000)	(1,430,000)
Other, net									120,000	295,000	(71,000)
Income (Loss) from Equity Method Investments									0	0	0
Payments to Acquire Property, Plant, and Equipment									164,000	(1,273,000)	15,785,000
Property, Plant and Equipment, Gross	29,681,000				30,700,000				29,681,000	30,700,000	30,161,000
Accumulated depreciation	(18,184,000)				(14,648,000)				(18,184,000)	(14,648,000)	(10,936,000)
Property, Plant and Equipment, Net In Service	11,497,000				16,052,000				11,497,000	16,052,000	19,225,000
Construction in progress	(207,000)				(1,645,000)				(207,000)	(1,645,000)	144,000
Net property and equipment	11,290,000				14,407,000				11,290,000	14,407,000	19,369,000
Investments, at Equity, and Advances to 50% or Less Owned Companies	0				0				0	0	0
Inventories	0				0				0	0	0
Goodwill	0				0				0	0	0
Intangible Assets	0				0				0	0	0
Other current and long-term assets, excluding cash and near cash assets	21,576,000								21,576,000		7,670,000
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues									0	0	0
Intersegment Eliminations [Member] | Offshore Marine Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									100,000	(124,000)	(183,000)
Intersegment Eliminations [Member] | Inland River Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									2,403,000	(2,881,000)	(3,862,000)
Intersegment Eliminations [Member] | Shipping Services [Member]
Segment Reporting Information [Line Items]
Operating Revenues									0	0	0
Intersegment Eliminations [Member] | Illinois Corn Processing Llc [Member]
Segment Reporting Information [Line Items]
Operating Revenues									0	0	0
Intersegment Eliminations [Member] | Witt O'Brien's LLC [Member]
Segment Reporting Information [Line Items]
Operating Revenues									133,000	(146,000)	0
Intersegment Eliminations [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Operating Revenues									0	0	0
Intersegment Eliminations [Member] | Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(2,636,000)	3,151,000	4,045,000
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Other Income (Expense) not included in Segment Profit									57,402,000	51,848,000	(4,790,000)
Less Equity Earnings included in Segment Profit									27,354,000	40,414,000	(16,309,000)
Cash and near cash assets	$ 673,593,000				$ 923,617,000				$ 673,593,000	$ 923,617,000	$ 786,644,000

Major Customers And Segment I86

Major Customers And Segment Information (Revenues Attributed By Geographical Region) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Operating Revenues	$ 213,036	$ 206,983	$ 197,038	$ 213,928	$ 250,631	$ 261,852	$ 281,609	$ 260,644	$ 830,985	$ 1,054,736	$ 1,319,394
Non-US [Member]
Segment Reporting Information [Line Items]
Concentration Risk, Percentage									29.00%	29.00%	30.00%
UNITED STATES
Segment Reporting Information [Line Items]
Operating Revenues									$ 590,310	$ 751,548	$ 925,750
Africa Primarily West Africa [Member]
Segment Reporting Information [Line Items]
Operating Revenues									37,764	57,268	70,743
Europe Primarily North Sea [Member]
Segment Reporting Information [Line Items]
Operating Revenues									82,730	104,042	112,644
Middle East and Asia [Member]
Segment Reporting Information [Line Items]
Operating Revenues									54,950	65,045	69,598
Brazil, Mexico Central And South America [Member]
Segment Reporting Information [Line Items]
Operating Revenues									64,837	76,404	140,460
Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues									$ 394	$ 429	$ 199

Major Customers And Segment I87

Major Customers And Segment Information (Property And Equipment Based Upon The Assets' Physical Location) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Net property and equipment	$ 1,555,668	$ 1,583,625	$ 1,502,673
UNITED STATES
Segment Reporting Information [Line Items]
Net property and equipment	1,185,917	1,181,586	1,120,765
Africa Primarily West Africa [Member]
Segment Reporting Information [Line Items]
Net property and equipment	75,772	73,406	82,495
Europe Primarily North Sea [Member]
Segment Reporting Information [Line Items]
Net property and equipment	83,767	72,544	75,382
Middle East and Asia [Member]
Segment Reporting Information [Line Items]
Net property and equipment	99,974	129,476	84,598
Brazil, Mexico Central And South America [Member]
Segment Reporting Information [Line Items]
Net property and equipment	$ 110,238	$ 126,613	$ 139,433

Supplemental Information For 88

Supplemental Information For Statements Of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Income taxes paid	$ 11,933	$ 23,791	$ 52,348
Income taxes refunded	3,933	4,550	2,055
Interest paid, excluding capitalized interest	26,662	23,957	24,719
Company financed sale of equipment and real property	7,950	1,768	45,305
Reclassification of Dorian to Marketable Securities	0	102,509	0
Services and Equipment received to settle notes receivable	0	2,500	0
Property, Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Services and Equipment received to settle notes receivable	14,400	0	0
U.S.-flag Harbor Tugs [Member]
Property, Plant and Equipment [Line Items]
Noncash or Part Noncash Divestiture, Amount of Consideration Received	$ 2,000	$ 0	$ 0

Quarterly Financial Informati89

Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Data [Abstract]
Operating Revenues	$ 213,036	$ 206,983	$ 197,038	$ 213,928	$ 250,631	$ 261,852	$ 281,609	$ 260,644	$ 830,985	$ 1,054,736	$ 1,319,394
Operating Income (Loss)	(99,364)	(33,016)	(30,151)	(10,016)	(928)	28,221	7,499	(13,667)	(172,547)	21,125	165,243
Net Income (Loss)	(90,289)	(34,026)	(50,933)	(20,524)	(49,853)	16,405	(8,501)	(17,901)	(195,772)	(59,850)	124,347
Net Income (Loss) attributable to SEACOR Holdings Inc.	$ (93,749)	$ (39,803)	$ (55,159)	$ (27,186)	$ (56,865)	$ 6,965	$ 687	$ (19,569)	$ (215,897)	$ (68,782)	$ 100,132
Basic Earnings (Loss) Per Common Share of SEACOR Holdings Inc.	$ (5.52)	$ (2.35)	$ (3.26)	$ (1.62)	$ (3.36)	$ 0.40	$ 0.04	$ (1.10)	$ (12.76)	$ (3.94)	$ 5.18
Diluted Earnings (Loss) Per Common Share of SEACOR Holdings Inc.	$ (5.52)	$ (2.35)	$ (3.26)	$ (1.62)	$ (3.36)	$ 0.40	$ 0.04	$ (1.10)	$ (12.76)	$ (3.94)	$ 4.71

Valuation And Qualifying Acco90

Valuation And Qualifying Accounts (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Valuation and Qualifying Accounts Disclosure [Line Items]
Inventory Valuation Reserves	$ 8,000	$ 670,000	$ 0	$ 26,000
Balance Beginning of Year	2,483,000	3,162,000	1,162,000
Bad debt expense (income)	7,054,000	842,000	2,618,000
Valuation Allowances and Reserves, Charged to Cost and Expense	(662,000)	670,000	(26,000)
Deductions	(1,190,000)	(997,000)	(1,279,000)
Valuation Allowances and Reserves, Reserves of Businesses Acquired	0	524,000	661,000
Balance End of Year	8,347,000	2,483,000	3,162,000
Inventory Valuation Reserve [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Deductions	0	0	0
Valuation Allowances and Reserves, Reserves of Businesses Acquired	$ 0	$ 0	$ 0