Seacor (CKH) 10-Q 24 Oct 18 2018 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 22, 2018
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	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		18,246,825

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current Assets:
Cash and cash equivalents	$ 324,564	$ 239,246
Restricted cash and restricted cash equivalents	2,990	2,982
Marketable securities	41,445	42,761
Receivables:
Trade, net of allowance for doubtful accounts of $3,465 and $2,390 in 2018 and 2017, respectively	151,217	110,465
Other	45,197	33,870
Inventories	5,139	4,377
Prepaid expenses and other	6,087	6,594
Total current assets	576,639	440,295
Property and Equipment:
Historical cost	1,403,886	1,380,469
Accumulated depreciation	(545,179)	(502,544)
Net property and equipment	858,707	877,925
Investments, at Equity, and Advances to 50% or Less Owned Companies	149,184	173,441
Construction Reserve Funds	5,908	51,339
Goodwill	32,767	32,761
Intangible Assets, Net	25,724	28,106
Other Assets	8,938	9,469
Total Assets	1,657,867	1,613,336
Current Liabilities:
Current portion of long-term debt	155,737	77,842
Accounts payable and accrued expenses	56,533	44,013
Other current liabilities	66,179	57,330
Total current liabilities	278,449	179,185
Long-Term Debt	372,657	501,505
Deferred Income Taxes	99,565	101,422
Deferred Gains and Other Liabilities	60,502	77,863
Total liabilities	811,173	859,975
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; 38,914,817 and 38,656,505 shares issued in 2018 and 2017, respectively	389	387
Additional paid-in capital	1,593,430	1,573,013
Retained earnings	479,495	419,128
Shares held in treasury of 20,671,627 and 20,716,878 in 2018 and 2017, respectively, at cost	(1,366,773)	(1,368,300)
Accumulated other comprehensive loss, net of tax	(444)	(545)
Stockholders' equity attributable to parent, total	706,097	623,683
Noncontrolling interests in subsidiaries	140,597	129,678
Total equity	846,694	753,361
Liabilities and stockholders' equity, total	$ 1,657,867	$ 1,613,336

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Trade receivables, allowance for doubtful accounts	$ 3,465	$ 2,390
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	60,000,000	60,000,000
Common stock, shares issued (in shares)	38,914,817	38,656,505
Treasury stock, shares held in treasury (in shares)	20,671,627	20,716,878
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0

Condensed Consolidated Statemen

Condensed Consolidated Statements Of Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Operating Revenues	$ 220,257	$ 176,605	$ 621,912	$ 441,495
Costs and Expenses [Abstract]
Operating	147,529	125,692	441,474	301,275
Administrative and general	26,083	20,531	76,189	68,949
Depreciation and amortization	18,616	20,501	57,069	54,689
Total costs and expenses	192,228	166,724	574,732	424,913
Gains on Asset Dispositions and Impairments, Net	6,018	5,209	13,569	10,918
Operating Income	34,047	15,090	60,749	27,500
Other Income (Expense):
Interest income	2,450	2,367	6,485	6,651
Interest expense	(8,335)	(9,121)	(25,502)	(31,101)
Debt extinguishment gains (losses), net	(160)	3	(5,609)	(94)
Marketable security gains (losses), net	1,713	(12,478)	(1,303)	(13,316)
Derivative gains, net	0	0	0	19,727
Foreign currency gains (losses), net	(328)	969	16	898
Other, net	357	64	54,951	68
Total Other Nonoperating Income (Expense)	(4,303)	(18,196)	29,038	(17,167)
Income (Loss) from Continuing Operations Before Income Tax Expense (Benefit) and Equity in Earnings of 50% or Less Owned Companies	29,744	(3,106)	89,787	10,333
Income Tax Expense (Benefit)	3,362	(12,795)	12,934	(12,563)
Income from Continuing Operations Before Equity in Earnings of 50% or Less Owned Companies	26,382	9,689	76,853	22,896
Equity in Earnings of 50% or Less Owned Companies, Net of Tax	821	488	1,915	2,929
Income from Continuing Operations	27,203	10,177	78,768	25,825
Income (Loss) from Discontinued Operations, Net of Tax	0	10,927	0	(23,150)
Net Income	27,203	21,104	78,768	2,675
Net Income attributable to Noncontrolling Interests in Subsidiaries	10,136	3,543	15,934	13,839
Net Income (Loss) attributable to SEACOR Holdings Inc.	$ 17,067	$ 17,561	$ 62,834	$ (11,164)
Basic Earnings (Loss) Per Common Share of SEACOR Holdings Inc.:
Continuing operations (in dollars per share)	$ 0.94	$ 0.38	$ 3.48	$ 0.55
Discontinued operations (in dollars per share)	0	0.62	0	(1.20)
Basic Earnings (Loss) Per Common Share of SEACOR Holdings Inc. (in dollars per share)	0.94	1	3.48	(0.65)
Diluted Earnings (Loss) Per Common Share of SEACOR Holdings Inc.:
Continuing operations (in dollars per share)	0.88	0.38	3.21	0.55
Discontinued operations (in dollars per share)	0	0.62	0	(1.19)
Diluted Earnings (Loss) Per Common Share of SEACOR Holdings Inc. (in dollars per share)	$ 0.88	$ 1	$ 3.21	$ (0.64)
Weighted Average Common Shares Outstanding:
Basic (in shares)	18,108,388	17,508,770	18,052,274	17,265,140
Diluted (in shares)	21,192,554	17,637,824	22,508,622	17,510,560

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net Income	$ 27,203	$ 21,104	$ 78,768	$ 2,675
Other Comprehensive Income:
Foreign currency translation gains (losses)	(76)	425	59	2,147
Reclassification of foreign currency translation losses to foreign currency gains (losses), net	15	0	15	0
Derivative losses on cash flow hedges	0	0	0	(389)
Other	0	5	0	(11)
Other Comprehensive Income (Loss), before Tax	(61)	430	74	1,889
Income tax benefit (expense)	2	(151)	27	(605)
Other Comprehensive Income (Loss), Net of Tax	(59)	279	101	1,284
Comprehensive Income	27,144	21,383	78,869	3,959
Comprehensive Income attributable to Noncontrolling Interests in Subsidiaries	10,136	3,543	15,934	14,000
Comprehensive Income (Loss) attributable to SEACOR Holdings Inc.	17,008	17,840	62,935	(10,041)
Interest Expense
Other Comprehensive Income:
Reclassification of derivative gains (losses) on cash flow hedges	0	0	0	33
Equity Method Investments
Other Comprehensive Income:
Reclassification of derivative gains (losses) on cash flow hedges	$ 0	$ 0	$ 0	$ 109

Condensed Consolidated Statem_3

Condensed Consolidated Statement Of Changes In Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Shares Held In Treasury	Accumulated Other Comprehensive Loss	Noncontrolling Interests In Subsidiaries
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Impact of adoption of accounting principle	$ (2,467)
December 31, 2017, As Adjusted	750,894	$ 387	$ 1,573,013	$ 416,661	$ (1,368,300)	$ (545)	$ 129,678
December 31, 2017 at Dec. 31, 2017	753,361	387	1,573,013	419,128	(1,368,300)	(545)	129,678
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee Stock Purchase Plan	1,527				1,527
Exercise of stock options	4,753	1	4,752
Director stock awards	106		106
Restricted stock	0	1	(1)
Net issuance of conversion option on exchange of convertible debt, net of tax	12,735		12,735
Purchase of conversion option in convertible debt, net of tax	(5)		(5)
Amortization of share awards	2,830		2,830
Acquisition of a subsidiary with noncontrolling interests	96						96
Distributions to noncontrolling interests	(5,111)						(5,111)
Net income	78,768			62,834			15,934
Other comprehensive income	101					101
September 30, 2018 at Sep. 30, 2018	$ 846,694	$ 389	$ 1,593,430	$ 479,495	$ (1,366,773)	$ (444)	$ 140,597

Condensed Consolidated Statem_4

Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Statement of Cash Flows [Abstract]
Net Cash Provided by Operating Activities of Continuing Operations	$ 35,799	$ 85,088
Cash Flows from Investing Activities of Continuing Operations:
Purchases of property and equipment	(43,736)	(99,306)
Proceeds from disposition of property and equipment	15,952	27,614
Investments in and advances to 50% or less owned companies	(9,836)	(7,636)
Return of investments and advances from 50% or less owned companies	8,176	9,676
Proceeds from the sale of 50% or less owned companies	78,015	5,000
Payments received on third-party leases and notes receivable, net	452	24,349
Withdrawals from construction reserve funds	45,431	37,714
Deposits into construction reserve funds	0	(13,807)
Business acquisitions, net of cash acquired	310	5,250
Net cash provided by (used in) investing activities of continuing operations	94,764	(11,146)
Cash Flows from Financing Activities of Continuing Operations:
Payments on long-term debt and capital lease obligations	(43,967)	(133,151)
Proceeds from issuance of long-term debt, net of issue costs	(2,495)	38,900
Purchase of conversion option in convertible debt	(5)	(1,354)
Common stock acquired for treasury	0	(7,569)
Proceeds from share award plans	6,280	16,427
Distributions to noncontrolling interests	(5,111)	0
Net cash used in financing activities of continuing operations	(45,298)	(86,747)
Effects of Exchange Rate Changes on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	61	856
Net Increase (Decrease) in Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents from Continuing Operations	85,326	(11,949)
Cash Flows from Discontinued Operations:
Operating Activities	0	26,875
Investing Activities	0	2,720
Financing Activities	0	(7,149)
Effects of Exchange Rate Changes on Cash and Cash Equivalents	0	208
Net Increase in Cash and Cash Equivalents from Discontinued Operations	0	22,654
Net Increase in Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	85,326	10,705
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Beginning of Period	242,228	258,887
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, End of Period	327,554	269,592
Restricted Cash and Restricted Cash Equivalents, End of Period	2,990	2,436
Cash and Cash Equivalents, End of Period	$ 324,564	$ 267,156

Basis of Presentation and Accou

Basis of Presentation and Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation and Accounting Policies	1. BASIS OF PRESENTATION AND ACCOUNTING POLICIES The condensed consolidated financial information for the three and nine months ended September 30, 2018 and 2017 has been prepared by the Company and has not been audited by its independent registered certified public accounting firm. The condensed consolidated financial statements include the accounts of SEACOR Holdings Inc. and its consolidated subsidiaries. In the opinion of management, all adjustments (consisting of normal recurring adjustments) have been made to fairly present the Company’s financial position as of September 30, 2018 , its results of operations for the three and nine months ended September 30, 2018 and 2017 , its comprehensive income (loss) for the three and nine months ended September 30, 2018 and 2017 , its changes in equity for the nine months ended September 30, 2018 , and its cash flows for the nine months ended September 30, 2018 and 2017 . Results of operations for the interim periods presented are not necessarily indicative of operating results for the full year or any future periods. Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States have been condensed or omitted. These condensed consolidated financial statements should be read in conjunction with the financial statements and related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 . Unless the context otherwise indicates, any reference in this Quarterly Report on Form 10-Q to the “Company” refers to SEACOR Holdings Inc. and its consolidated subsidiaries and any reference in this Quarterly Report on Form 10-Q to “SEACOR” refers to SEACOR Holdings Inc. without its consolidated subsidiaries. Capitalized terms used and not specifically defined herein have the same meaning given those terms in the Company's Annual report on Form 10-K for the year ended December 31, 2017 . Adoption of New Accounting Standards. On January 1, 2018, the Company adopted Financial Accounting Standard Board (“FASB”) Topic 606, Revenue from Contracts with Customers (“Topic 606”). As a consequence of adopting Topic 606, the Company now recognizes all of the operating revenues and expenses associated with the dry-cargo barge pools it manages along with additional operating expenses reflective of barge pool earnings attributable to third-party barge owners and not the Company in its capacity as manager. Under Topic 606, the Company determined it was a principal with respect to the third-party barge owners. Previously, the Company recognized operating revenues and expenses only for its proportionate share of the barge pools in which it participated, as it acted as an agent. All prior period results have been adjusted to reflect the retrospective adoption of Topic 606. The adoption of Topic 606 had no impact on previously reported operating income, net income or earnings per share. On January 1, 2018, the Company adopted ASU 2016-16, Intra-Entity Transfers of Assets Other Than Inventory , which eliminates the deferral of the tax effects of intercompany asset sales other than inventory until the transferred assets are sold to a third party or recovered through use. As a result of the adoption of the standard, the deferred tax charges previously recognized from those sales resulted in a decrease in deferred tax assets and a cumulative adjustment to retained earnings of $2.5 million in the condensed consolidated balance sheet and statement of changes in equity as of January 1, 2018. Discontinued Operations. On June 1, 2017, the Company completed the spin-off of SEACOR Marine Holdings Inc. (“SEACOR Marine”), the company that operated SEACOR’s Offshore Marine Services business segment, by means of a dividend of all the issued and outstanding common stock of SEACOR Marine to SEACOR’s shareholders (the “Spin-off”). SEACOR Marine is now an independent company whose common stock is listed on the New York Stock Exchange under the symbol “SMHI.” For all periods presented herein, the Company has reported the historical financial position, results of operations and cash flows of SEACOR Marine as discontinued operations (see Note 14). On July 3, 2017, the Company completed the sale of its 70% interest in Illinois Corn Processing LLC (“ICP”), the company that operated SEACOR’s Illinois Corn Processing business segment. For all periods presented herein, the Company has reported the historical financial position, results of operations and cash flows of ICP as discontinued operations (see Note 14). Revenue Recognition. Revenue is recognized when (or as) the Company transfers promised goods or services to its customers in amounts that reflect the consideration to which the Company expects to be entitled to in exchange for those goods or services, which occurs when (or as) the Company satisfies its contractual obligations and transfers control of the promised goods or services to its customers. Costs to obtain or fulfill a contract are expensed as incurred. Revenue from Contracts with Customers. Ocean Services primarily earns revenues from voyage charters, contracts of affreightment, harbor and ocean towing services, unit freight transportation services and technical ship management agreements with vessel owners (see Note 13). Ocean Services transfers control of the service to the customer and satisfies its performance obligation over the term of the contract, and therefore recognizes revenue over the term of the contract while related costs are expensed as incurred. Voyage charters are contracts to carry cargoes on a single voyage basis for a predetermined price, 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. Harbor and ocean towing services typically include operating harbor tugs alongside oceangoing vessels to escort them to their berth, assisting with the docking and undocking of these oceangoing vessels and escorting them back out to sea. They are contracted using prevailing port tariff terms on a per-use basis. In the unit freight trade, transportation services typically include transporting shipping containers, rail cars, project cargoes, automobiles and U.S. military vehicles and are generally contracted on a per unit basis for the specified cargo and destination, typically in accordance with a publicly available tariff rate or based on a negotiated rate when moving larger volumes over an extended period. Other operations primarily include technical ship management agreements whereby Ocean Services provides technical ship management services to third-party customers for a predetermined price over a specified period of time, typically a year or more. Inland Services primarily earns revenues from contracts of affreightment, terminal operations, fleeting operations and repair and maintenance services (see Note 13). Inland Services transfers control of the service to the customer and satisfies its performance obligation over the term of the contract, and therefore recognizes revenue over the term of the contract while related costs are expensed as incurred. Contracts of affreightment are contracts whereby customers are charged an established rate per ton to transport cargo from point-to-point. Terminal operations includes tank farms and dry bulk and container handling facilities that are marketed under contractual rates and terms driven by throughput volume. Fleeting operations includes fleeting services whereby barges are held in fleeting areas for an agreed-upon day rate and shifting services whereby harbor boats are used to pick up and drop off barges to assist in assembling tows and to move barges to and from the dock for loading and unloading at predetermined per-shift fees. Other operations primarily include a machine shop specializing in towboat and barge cleaning, repair and maintenance services that are charged on an hourly or a fixed fee basis depending on the scope and nature of the work. Witt O’Brien’s primarily earns revenues from time and material and retainer contracts (see Note 13). Witt O’Brien’s transfers control of the service to the customer and satisfies its performance obligation over the term of the contract, and therefore recognizes revenue over the term of the contract while related costs are expensed as incurred. Time and material contracts primarily relate to emergency response, debris management or consulting services that Witt O’Brien’s performs for a predetermined fee. Retainer contracts, which are nearly all with vessel services operators and oil companies, are contracted based on agreed-upon rates. The Company’s Other business segment includes CLEANCOR Energy Solutions LLC (“Cleancor”) (see Note 2). Cleancor primarily earns revenues from the sale of liquefied natural gas (see Note 13). Under these arrangements, control of the goods are transfered to the customer and performance obligations are satisfied at a point in time, and therefore revenue is recognized upon delivery while any related costs are expensed as incurred. Contract liabilities from contracts with customers arise when the Company has received consideration prior to performance and are included in other current liabilities in the accompanying condensed consolidated balance sheets. The Company’s contract liability activity for the nine months ended September 30 was as follows (in thousands): 2018 Balance at beginning of period $ 983 Contract liabilities arising during the period 4,374 Revenue recognized upon completion of performance obligations during the period (2,291 ) Balance at end of period $ 3,066 Lease Revenues. The Company’s lease revenues are primarily from time charters, bareboat charters and non-vessel rental agreements that are recognized ratably over the lease term as services are provided, typically on a per day basis. Under a time charter, the Company provides a vessel to a customer for a set term and is responsible for all operating expenses, typically excluding fuel. Under a bareboat charter, the Company provides a vessel to a customer for a set term and the customer assumes responsibility for all operating expenses and risks of operation. Under a non-vessel rental agreement, the Company provides non-vessel property or equipment to a customer for a set term and the customer assumes responsibility for all operating expenses and risks of operation. Property and Equipment. Equipment, stated at cost, is depreciated using the straight-line method over the estimated useful life of the asset to an estimated salvage value. With respect to each class of asset, the estimated useful life is based upon a newly built asset being placed into service and represents the time period beyond which it is typically not justifiable for the Company to continue to operate the asset in the same or similar manner. From time to time, the Company may acquire older assets that have already exceeded their useful life as set forth in the Company’s useful life policy, in which case the Company depreciates such assets based on its best estimate of remaining useful life, typically the next survey or certification date. As of September 30, 2018 , the estimated useful life (in years) of each of the Company’s major categories of new equipment was as follows: Petroleum and chemical carriers - U.S.-flag 25 Harbor and offshore tugs 25 Ocean liquid tank barges 25 Short-sea container/RORO (1) vessels 20 Dry bulk carriers - U.S.-flag 25 Inland river dry-cargo and specialty barges 20 Inland river liquid tank barges 25 Inland river towboats and harbor boats 25 Terminal and fleeting facilities 20 ______________________ (1) Roll On/Roll Off. Equipment maintenance and repair costs including the costs of routine overhauls, dry-dockings 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. As of September 30, 2018 , the Company’s construction in progress totaling $4.6 million primarily consisted of upgrades to inland river towboats and the construction of other Inland Services equipment, and is included in historical cost in the accompanying condensed consolidated balance sheets. Certain interest costs incurred during the construction of equipment are capitalized as part of the assets’ carrying values and are amortized over such assets’ estimated useful lives. During the nine months ended September 30, 2018 , capitalized interest totaled $0.2 million . Impairment of Long-Lived Assets. The Company performs an impairment analysis of long-lived assets used in operations, including intangible assets, when indicators of impairment are present. 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 value and impairment charges are recorded if the carrying value exceeds fair value. The Company performs its testing on an asset or asset group basis. The Company’s estimates of undiscounted cash flows are highly subjective and actual results may vary from the Company’s estimates due to the uncertainty regarding projected financial performance. Generally, fair value is determined using valuation techniques, such as expected discounted cash flows or appraisals, as appropriate. During the nine months ended September 30, 2018 , the Company did not recognize any impairment charges related to long-lived assets held for use. During the nine months ended September 30, 2017 , the Company recognized impairment charges of $0.4 million related to long-lived assets held for use. 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 nine months ended September 30, 2018 and 2017 , the Company recognized impairment charges of $0.1 million and $0.9 million , respectively, related to its 50% or less owned companies, which are included in equity in earnings of 50% or less owned companies, net of tax in the accompanying consolidated statements of income (loss). Income Taxes. During the nine months ended September 30, 2018 , the Company’s effective income tax rate of 14.4% was primarily due to foreign sourced income not subject to U.S. tax partially offset by income taxes on Subpart F income (see Note 6). Deferred Gains. The Company has sold certain equipment to its 50% or less owned companies, entered into vessel sale-leaseback transactions with finance companies, and provided seller financing on sales of its equipment to third parties and its 50% or less owned companies. A portion of the gains realized from these transactions were deferred and recorded in deferred gains and other liabilities in the accompanying condensed consolidated balance sheets. Deferred gain activity related to these transactions for the nine months ended September 30 was as follows (in thousands): 2018 2017 Balance at beginning of period $ 72,453 $ 82,423 Deferred gains arising from asset sales — 7,720 Amortization of deferred gains included in operating expenses as a reduction to rental expense (8,991 ) (11,126 ) Amortization of deferred gains included in gains on asset dispositions and impairments, net (1) (6,988 ) (1,764 ) Reclassification of deferred gains into historical cost on reacquired property and equipment (3,052 ) — Balance at end of period $ 53,422 $ 77,253 ______________________ (1) For the nine months ended September 30, 2018 , the Company recognized previously deferred gains of $5.5 million due to a change in the lease duration for one U.S.-flag petroleum and chemical carrier. Accumulated Other Comprehensive Loss. The only component of accumulated other comprehensive loss for the nine months ended September 30, 2018 was foreign currency translation adjustments. Earnings Per Share. Basic earnings per common share of SEACOR is computed based on the weighted average number of common shares issued and outstanding during the relevant periods. Diluted earnings per common share of SEACOR is computed based on the weighted average number of common shares issued and outstanding plus the effect of potentially dilutive securities through the application of the treasury stock and if-converted methods. Dilutive securities for this purpose assumes restricted stock grants have vested, common shares have been issued pursuant to the exercise of outstanding stock options and common shares have been issued pursuant to the conversion of all outstanding convertible notes. Computations of basic and diluted earnings per common share of SEACOR were as follows (in thousands, except share data): Three Months Ended September 30, Nine Months Ended September 30, Net Income attributable to SEACOR Average O/S Shares Per Share Net Income (Loss) Attributable to SEACOR Average O/S Shares Per Share 2018 Basic Weighted Average Common Shares Outstanding $ 17,067 18,108,388 $ 0.94 $ 62,834 18,052,274 $ 3.48 Effect of Dilutive Share Awards: Options and Restricted Stock (1) — 303,285 — 299,405 Convertible Notes (2) 1,625 2,780,881 9,495 4,156,943 Diluted Weighted Average Common Shares Outstanding $ 18,692 21,192,554 $ 0.88 $ 72,329 22,508,622 $ 3.21 2017 Basic Weighted Average Common Shares Outstanding $ 17,561 17,508,770 $ 1.00 $ (11,164 ) 17,265,140 $ (0.65 ) Effect of Dilutive Share Awards: Options and Restricted Stock (3) — 129,054 — 245,420 Convertible Notes (4) — — — — Diluted Weighted Average Common Shares Outstanding $ 17,561 17,637,824 $ 1.00 $ (11,164 ) 17,510,560 $ (0.64 ) ______________________ (1) For the three and nine months ended September 30, 2018 , diluted earnings per common share of SEACOR excluded 295,074 and 292,169 , respectively, of certain share awards as the effect of their inclusion in the computation would be anti-dilutive. (2) For the three months ended September 30, 2018 , diluted earnings per common share of SEACOR excluded 1,408,719 of common shares issuable pursuant to the Company’s 3.0% Convertible Senior Notes as the effect of their inclusion in the computation would be anti-dilutive. (3) For the three and nine months ended September 30, 2017 , diluted earnings per common share of SEACOR excluded 1,727,132 and 2,638,753 , respectively, of certain share awards as the effect of their inclusion in the computation would be anti-dilutive. Diluted weighted average shares outstanding are calculated based on continuing operations. (4) For the three and nine months ended September 30, 2017 , diluted earnings per common share of SEACOR excluded 1,889,027 and 2,488,460 , respectively, of common shares issuable pursuant to the Company’s 2.5% Convertible Senior Notes and 2,801,147 and 2,801,147 , respectively, of common shares issuable pursuant to the Company’s 3.0% Convertible Senior Notes as the effect of their inclusion in the computation would be anti-dilutive. Diluted weighted average shares outstanding are calculated based on continuing operations. New Accounting Pronouncements. On February 25, 2016, the FASB issued a comprehensive new leasing standard that is meant to improve transparency and comparability among companies by requiring lessees to recognize a lease liability and a corresponding lease asset for virtually all lease contracts and also requires additional disclosures about leasing arrangements. The new standard is effective for interim and annual periods beginning after December 15, 2018. The Company will adopt this standard using a modified prospective approach to adoption with recognition of a cumulative-effect adjustment to the opening balance of retained earnings at the adoption date. The Company is in the process of preparing for implementation and currently believes that the adoption will have a material impact on its financial statements. Specifically, the Company will be recording material right-of-use assets and lease liabilities of approximately $150 - $175 million for certain of its equipment, office and land leases. The Company’s estimates are preliminary and are based on its current inventory of leases. If the Company enters into or exits material lease arrangements prior to adoption or makes material changes to certain of its assumptions, including lease discount rates, the Company’s estimates may change and those changes may be material. On January 26, 2017, the FASB issued an amendment to the accounting standards, which simplified wording and removed step two of the goodwill impairment test. A goodwill impairment will now be the amount by which a reporting unit’s 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.

Business Acquisitions

Business Acquisitions	9 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
Business Acquisitions	2. BUSINESS ACQUISITIONS Cleancor . On June 1, 2018, the Company acquired a controlling interest in Cleancor, a full service solution provider that delivers clean fuel to end users, through the acquisition of its partners’ 50% equity interest for $3.2 million in cash. In addition, immediately prior to consolidation, the Company contributed as capital $1.9 million of notes receivable due from Cleancor. The Company performed a fair value analysis and the purchase price was allocated to the acquired assets and liabilities based on their fair value resulting in no goodwill being recorded. SCA. On March 1, 2018, the Company acquired Strategic Crisis Advisors LLC (“SCA”) for $1.3 million to be paid in two installments. The purchase price includes $0.8 million in contingent consideration that is dependent upon SCA meeting predetermined revenue targets for the twelve months following the acquisition date. The Company performed a fair value analysis and the purchase price was allocated to the acquired assets and liabilities based on their fair value resulting in no goodwill being recorded. Purchase Price Allocation. The allocation of the purchase price for the Company’s acquisitions for the nine months ended September 30, 2018 was as follows (in thousands): Trade and other receivables $ 1,264 Other current assets 170 Investments, at Equity, and Advances to 50% or Less Owned Companies (3,219 ) Property and Equipment 4,382 Intangible Assets 950 Notes receivable contributed as equity (1,904 ) Other Assets 7 Accounts payable and other accrued liabilities (1) (1,609 ) Other current liabilities (269 ) Noncontrolling interests in subsidiaries (82 ) Purchase price (2) $ (310 ) ______________________ (1) Includes $1.3 million of consideration to be paid in two installments. (2) Purchase price is net of cash acquired totaling $3.6 million .

Equipment Acquisitions and Disp

Equipment Acquisitions and Dispositions	9 Months Ended
	Sep. 30, 2018
Property, Plant and Equipment [Abstract]
Equipment Acquisitions and Dispositions	3. EQUIPMENT ACQUISITIONS AND DISPOSITIONS During the nine months ended September 30, 2018 , capital expenditures were $43.7 million . Equipment deliveries during the nine months ended September 30, 2018 included five U.S.-flag harbor tugs and two foreign-flag short-sea container/RORO vessels. During the nine months ended September 30, 2018 , the Company sold one U.S.-flag petroleum and chemical carrier, one U.S.-flag harbor tug, 32 dry-cargo barges, two inland river specialty barges and other equipment for net proceeds of $16.0 million and gains of $6.6 million , all of which were recognized currently. In addition, the Company recognized previously deferred gains of $7.0 million .

Investments, At Equity, And Adv

Investments, At Equity, And Advances To 50% Or Less Owned Companies	9 Months Ended
	Sep. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Investments, At Equity, And Advances To 50% Or Less Owned Companies	4. INVESTMENTS, AT EQUITY, AND ADVANCES TO 50% OR LESS OWNED COMPANIES RF Vessel Holdings. RF Vessel Holdings owns two foreign-flag rail ferries. During the nine months ended September 30, 2018 , the Company and its partner each contributed capital of $0.9 million to RF Vessel Holdings. Golfo de Mexico. Golfo de Mexico operates the two foreign-flag rail ferries owned by RF Vessel Holdings. During the nine months ended September 30, 2018 , the Company and its partner each contributed capital of $2.1 million to Golfo de Mexico. KSM. KSM operates four foreign-flag harbor tugs and one foreign-flag ocean liquid tank barge in Freeport, Grand Bahama. During the nine months ended September 30, 2018 , the Company and its partner each contributed capital of $1.0 million to KSM. SCFCo. SCFCo operates dry-cargo barges and towboats on the Parana-Paraguay Rivers and a terminal facility at Port Ibicuy, Argentina. The Company has provided SCFCo with working capital advances, loans and financings. During the nine months ended September 30, 2018 , the Company received repayments on these working capital advances, loans and financings of $2.4 million from SCFCo. As of September 30, 2018 , $30.0 million of working capital advances, loans and financings remained outstanding. SCF Bunge Marine. SCF Bunge Marine provides towing services on the U.S. Inland Waterways, primarily the Mississippi River, Illinois River, Tennessee River and Ohio River. During the nine months ended September 30, 2018 , the Company contributed capital of $0.5 million to SCF Bunge Marine and received dividends of $2.9 million from SCF Bunge Marine. O’Brien’s do Brazil. O’Brien’s do Brazil is an emergency consulting organization providing preparedness, response and recovery services in Brazil. During the nine months ended September 30, 2018 , the Company received dividends of $0.2 million from O’Brien’s do Brazil. Hawker Pacific. Hawker Pacific is an aviation sales and support organization and distributor of aviation components from leading manufacturers. On April 30, 2018, the Company sold its 34.2% interest in Hawker Pacific for $78.0 million in cash and recognized a gain of $53.9 million , which is included in other, net in the accompanying condensed consolidated statements of income (loss). 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. During the nine months ended September 30, 2018 , the Company received dividends of $0.4 million from VA&E. The Company provides an uncommitted revolving credit facility of up to $3.5 million and a subordinated loan of $3.5 million to VA&E. During the nine months ended September 30, 2018 , the Company received repayments of $5.4 million and advanced $5.4 million on the revolving credit facility. As of September 30, 2018 , the outstanding balance on the revolving credit facility and subordinated loan was $7.3 million , inclusive of accrued and unpaid interest. Other. The Company’s other 50% or less owned companies are primarily industrial aviation businesses in Asia. During the nine months ended September 30, 2018 , the Company received dividends of $0.8 million and repayments on advances of $0.4 million from these 50% or less owned companies. As of September 30, 2018 , total advances outstanding were $2.0 million .

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2018
Long-term Debt and Capital Lease Obligations [Abstract]
Long-Term Debt	5. LONG-TERM DEBT SEACOR’s Board of Directors previously approved a securities repurchase plan that authorizes the Company to acquire SEACOR common stock, par value $0.01 per share (“Common Stock”), 7.375% Senior Notes, 3.0% Convertible Senior Notes, 3.25% Convertible Senior Notes and 2.5% Convertible Senior Notes (collectively the “Securities”) through open market purchases, privately negotiated transactions or otherwise, depending on market conditions. As of September 30, 2018 , the Company’s remaining repurchase authority for the Securities was $71.1 million . 3.0% Convertible Senior Notes. On May 15, 2018, SEACOR exchanged $117.8 million aggregate principal amount of the Company’s outstanding 3.0% Convertible Senior Notes due 2028 for a like principal amount of new 3.25% Convertible Senior Notes due 2030 (see discussion below). In addition, during the nine months ended September 30, 2018 , the Company repurchased $0.3 million in principal amount of its 3.0% Convertible Senior Notes for $0.3 million . These transactions resulted in debt extinguishment losses of $5.3 million included in the accompanying condensed consolidated statements of income (loss). The outstanding principal amount of these notes was $111.9 million as of September 30, 2018 . 3.25% Convertible Senior Notes. On May 15, 2018, SEACOR issued $117.8 million aggregate principal amount of its 3.25% Convertible Senior Notes due May 15, 2030 (the “ 3.25% Convertible Senior Notes”). Interest on the 3.25% Convertible Senior Notes is payable semi-annually on May 15 and November 15 of each year. Beginning May 15, 2025, contingent interest is payable during any subsequent semi-annual interest period if the average trading price of the 3.25% Convertible Senior Notes for a defined period is greater than or equal to $1,200 per bond ( $1,000 face value). 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 3.25% Convertible Senior Notes. Prior to February 15, 2030, the 3.25% Convertible Senior Notes are convertible into shares of Common Stock, at a conversion rate (“Conversion Rate”) of 13.1920 shares per bond ( $1,000 face value) only if certain conditions are met, as more fully described in the indenture. After February 15, 2030, holders may elect to convert at any time. The Company has reserved the maximum number of shares of Common Stock needed upon conversion, or 1,553,780 shares as of September 30, 2018. On or after May 15, 2022, the 3.25% 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 May 15, 2025, or if the Company undergoes a fundamental change, as more fully described in the indenture, the holders of the 3.25% 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 3.25% Convertible Senior Notes and the associated underwriting fees in a manner that reflects the Company’s non-convertible borrowing rate. Of the total issued amount of $117.8 million and offering costs of $2.5 million , the Company allocated $95.1 million and $2.0 million , respectively, to the liability component and $22.7 million and $0.5 million , respectively, to the equity component. The resulting debt discount and offering costs associated with the liability component are amortized as additional non-cash interest expense over the seven year period for which the debt is expected to be outstanding (May 15, 2025) for an overall effective annual interest rate of 7.2% . 7.375% Senior Notes. During the nine months ended September 30, 2018 , the Company repurchased $5.7 million in principal amount of its 7.375% Senior Notes for $5.9 million resulting in debt extinguishment losses of $0.2 million included in the accompanying condensed consolidated statements of income (loss). The outstanding principal amount of these notes was $147.4 million as of September 30, 2018 . On October 1, 2018, the Company announced it would redeem all of its 7.375% Senior Notes on October 31, 2018 at a redemption price equal to 100% of the principal amount of the notes outstanding plus a make-whole premium to be calculated in accordance with the terms of the indenture governing the 7.375% Senior Notes, plus accrued and unpaid interest, if any, to the redemption date. As a consequence, the Company has included the principal amount of these notes in current portion of long-term debt in the accompanying condensed consolidated balance sheet. SEA-Vista Credit Facility. During the nine months ended September 30, 2018 , SEA-Vista repaid $17.0 million on the Revolving Loan and made scheduled payments of $2.5 million on the Term A-1 Loan and $4.2 million on the Term A-2 Loan. As of September 30, 2018 , SEA-Vista had $72.0 million of remaining borrowing capacity under the Revolving Loan. ISH Credit Facility. During the nine months ended September 30, 2018 , ISH repaid the outstanding balance of $12.2 million on the ISH Term Loan and terminated the credit facility resulting in debt extinguishment losses of $0.1 million included in the accompanying condensed consolidated statements of income (loss). Other. During the nine months ended September 30, 2018 , the Company made scheduled payments on other long-term debt of $0.5 million and repaid the remaining outstanding balance of $1.4 million assumed in the ISH acquisition. Letters of Credit. As of September 30, 2018 , the Company had outstanding letters of credit totaling $10.1 million with various expiration dates through 2019 , including $0.7 million that have been issued on behalf of SEACOR Marine. Guarantees. The Company has guaranteed the payments of amounts owed under certain sale-leaseback transactions, equipment financing and multi-employer pension obligations on behalf of SEACOR Marine. As of September 30, 2018 , these guarantees on behalf of SEACOR Marine totaled $47.0 million and decline as payments are made on the outstanding obligations. The Company earns a fee of 50 basis points per annum on these guarantees and outstanding letters of credit. For the three and nine months ended September 30, 2018 , the Company earned fees of $0.1 million and $0.2 million , respectively.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	6. INCOME TAXES The following table reconciles the difference between the statutory federal income tax rate for the Company and the effective income tax rate on continuing operations for the nine months ended September 30, 2018 : Statutory rate 21.0 % Income subject to tonnage tax (2.4 )% Noncontrolling interests (3.7 )% Foreign earnings not subject to U.S. income tax (17.7 )% Foreign taxes not creditable against U.S. income tax 4.1 % Subpart F income 12.3 % State taxes 0.7 % Other 0.1 % 14.4 %

Derivative Instruments And Hedg

Derivative Instruments And Hedging Strategies	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments And Hedging Strategies	7. DERIVATIVE INSTRUMENTS AND HEDGING STRATEGIES The Company recognized gains on derivative instruments not designated as hedging instruments for the nine months ended September 30 as follows (in thousands): 2018 2017 Exchange option liability on subsidiary convertible senior notes $ — $ 19,436 Forward currency exchange, option and future contracts — 291 $ — $ 19,727 The exchange option liability on subsidiary convertible senior notes terminated as a consequence of the Spin-off as the notes became the sole obligation of SEACOR Marine and convertible only into the common stock of SEACOR Marine. The Company enters and settles forward currency exchange, option and future contracts with respect to various foreign currencies. 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. As of September 30, 2018 , there were no outstanding forward currency exchange contracts.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	8. FAIR VALUE MEASUREMENTS The fair value of an asset or liability is the price that would be received to sell an asset or transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company utilizes a fair value hierarchy that maximizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value and defines three levels of inputs that may be used to measure fair value. Level 1 inputs are quoted prices in active markets for identical assets or liabilities. Level 2 inputs are observable inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly, including quoted prices for similar assets or liabilities in active markets, quoted prices in markets that are not active, inputs other than quoted prices that are observable for the asset or liability, or inputs derived from observable market data. Level 3 inputs are unobservable inputs that are supported by little or no market activity and are significant to the fair value of the assets or liabilities. The Company’s financial assets and liabilities as of September 30, 2018 that are measured at fair value on a recurring basis were as follows (in thousands): Level 1 Level 2 Level 3 ASSETS Cash, cash equivalents, restricted cash and restricted cash equivalents $ 327,554 $ — $ — Marketable securities (1) 41,445 — — Construction reserve funds 5,908 — — ______________________ (1) Marketable security gains (losses), net include unrealized gains of $1.7 million and unrealized losses of $7.1 million for the three months ended September 30, 2018 and 2017 , respectively, related to marketable security positions held by the Company as of September 30, 2018 . Marketable security gains (losses), net include unrealized losses of $1.3 million and $7.2 million for the nine months ended September 30, 2018 and 2017 , respectively, related to marketable security positions held by the Company as of September 30, 2018 . The estimated fair values of the Company’s other financial assets and liabilities as of September 30, 2018 were as follows (in thousands): Estimated Fair Value Carrying Amount Level 1 Level 2 Level 3 ASSETS Notes receivable from third parties (included in other receivables and other assets) $ 2,226 $ — $ 2,203 $ — Investments, at cost, in 50% or less owned companies (included in other assets) 4,300 see below LIABILITIES Long-term debt, including current portion (1) $ 528,394 $ — $ 561,044 $ — ______________________ (1) The estimated fair value includes the embedded conversion options on the Company’s 3.0% Convertible Senior Notes and 3.25% Convertible Senior Notes. The fair value of the Company’s long-term debt and notes receivable from third parties 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. 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 other assets and liabilities that were measured at fair value during the nine months ended September 30, 2018 were as follows (in thousands): Level 1 Level 2 Level 3 ASSETS Investments, at equity, and advances in 50% or less owned companies $ — $ 3,219 $ — Investments, at equity, and advances in 50% or less owned companies. During the nine months ended September 30, 2018 , the Company marked its investment in Cleancor to fair value as a consequence of the Company acquiring its partners’ 50% interest, resulting in a gain of $0.1 million , net of tax, based on the fair value of the acquired interest (see Note 2). In addition, during the nine months ended September 30, 2018 , the Company identified indicators of impairment in one of its 50% or less owned companies and, as a consequence, recognized an impairment charge of $0.1 million for an other-than-temporary decline in fair value. The investment was determined to have an immaterial value.

Noncontrolling Interests in Sub

Noncontrolling Interests in Subsidiaries	9 Months Ended
	Sep. 30, 2018
Noncontrolling Interest [Abstract]
Noncontrolling Interests in Subsidiaries	9. NONCONTROLLING INTERESTS IN SUBSIDIARIES Noncontrolling interests in the Company’s consolidated subsidiaries were as follows (in thousands): Noncontrolling Interests September 30, 2018 December 31, 2017 Ocean Services: SEA-Vista 49% $ 139,566 $ 128,550 Inland Services: Other 3.0 % – 51.8% 841 977 Other 5.0 % – 11.8% 190 151 $ 140,597 $ 129,678 SEA-Vista. SEA-Vista owns and operates the Company’s fleet of U.S.-flag petroleum and chemical carriers used in the U.S. coastwise trade of crude oil, petroleum and specialty chemical products. As of September 30, 2018 , the net assets of SEA-Vista were $284.8 million . During the nine months ended September 30, 2018 , the net income of SEA-Vista was $32.6 million , of which $16.0 million was attributable to noncontrolling interests. During the nine months ended September 30, 2017 , the net income of SEA-Vista was $33.2 million , of which $16.3 million was attributable to noncontrolling interests.

Multi-Employer and Defined Bene

Multi-Employer and Defined Benefit Pension Plans	9 Months Ended
	Sep. 30, 2018
Retirement Benefits [Abstract]
Multi-Employer and Defined Benefit Pension Plans	10. MULTI-EMPLOYER AND DEFINED BENEFIT PENSION PLANS AMOPP. During the nine months ended September 30, 2018 , the Company received notification from the AMOPP that the Company’s withdrawal liability as of September 30, 2017 would have been $34.4 million based on an actuarial valuation performed as of that date. That liability may change in future years based on various factors, primarily employee census. As of September 30, 2018 , the Company has no intention to withdraw from the AMOPP and no deficit amounts have been invoiced. Depending upon the results of the future actuarial valuations and the ten-year rehabilitation plan, it is possible that the AMOPP will experience further funding deficits, requiring the Company to recognize additional payroll related operating expenses in the periods invoices are received or contribution levels are increased.

Share Based Compensation

Share Based Compensation	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share Based Compensation	11. SHARE BASED COMPENSATION Transactions in connection with the Company’s share based compensation plans during the nine months ended September 30, 2018 were as follows: Director stock awards granted 2,250 Employee Stock Purchase Plan (“ESPP”) shares issued 45,251 Restricted stock awards granted 121,850 Stock Option Activities: Outstanding as of December 31, 2017 1,546,014 Granted 110,660 Exercised (134,212 ) Outstanding as of September 30, 2018 1,522,462 Shares available for future grants and ESPP purchases as of September 30, 2018 916,254 Employee Stock Purchase Plans. On June 5, 2018, SEACOR’s stockholders approved an amendment to the 2009 Employee Stock Purchase Plan, whereby the number of shares available under the plan was increased by 300,000 .

Commitments And Contingencies

Commitments And Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	12. COMMITMENTS AND CONTINGENCIES The Company's capital commitments as of September 30, 2018 by year of expected payment were as follows (in thousands): Remainder of 2018 2019 Total Ocean Services $ 106 $ — $ 106 Inland Services 2,478 2,690 5,168 $ 2,584 $ 2,690 $ 5,274 Ocean Services’ and Inland Services’ capital commitments included one inland river towboat and various other equipment and vessel improvements. Subsequent to September 30, 2018, the Company committed to purchase additional property and equipment for $14.7 million . 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 private equity firm (the “SES Business Transaction”). On December 15, 2010, O’Brien’s Response Management L.L.C. (“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, which is currently pending in the U.S. District Court for the Eastern District of Louisiana (the “MDL”). The “B3” master complaint naming ORM and NRC asserted 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 “B3” 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. On February 16, 2016, all but eleven B3 claims against ORM and NRC were dismissed with prejudice (the “B3 Dismissal Order”). On August 2, 2016, the Court granted an omnibus motion for summary judgment as it concerns ORM and NRC in its entirety, dismissing the remaining eleven plaintiffs’ claims against ORM and NRC with prejudice (the “Remaining Eleven Plaintiffs’ Dismissal Order”). The deadline to appeal both of these orders has expired. At present, the only remaining claim is the following: • 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. Following a status conference with the Court on February 17, 2017, the Court issued several new pretrial orders in connection with the remaining claims in the MDL. Various submissions followed, and on July 18, 2017, the Court issued an order dismissing all remaining “B3” claims in the MDL with prejudice, with the exception of certain claims specifically listed on an exhibit annexed to the order (the “Master MDL B3 Dismissal Order”). Nathan Fitzgerald, the decedent in the Fitzgerald Action, was listed on the exhibit annexed to the Master MDL B3 Dismissal Order. The Court has since issued a list of those plaintiffs compliant with its previous orders and thus whose “B3” claims remain pending; the last version of this compliance list was issued on April 6, 2018 and the claim for the decedent in the Fitzgerald Action remains listed as a pending claim. On April 9, 2018, the Court issued an order requiring remaining “B3” plaintiffs to submit particularized statements of claim, and such a statement was submitted on behalf of the decedent in the Fitzgerald Action on July 9, 2018. On September 20, 2018, the Court issued an order indicating which statements of claim were sufficient and which were not, requiring the latter plaintiffs to show cause; the statement submitted on behalf of the decedent in the Fitzgerald Action was deemed sufficient, requiring nothing further at the time of the order. The Company is unable to estimate the potential exposure, if any, resulting from this matter, to the extent it remains viable, but believes it is without merit and does not expect that it 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 “B3” master complaint that have already been asserted against ORM and NRC. Various contribution and indemnity cross-claims and counterclaims involving ORM and NRC were subsequently filed. The Company believes that the potential exposure, if any, resulting therefrom has been reduced as a result of the various developments in the MDL, including the B3 Dismissal Order and Remaining Eleven Plaintiffs’ 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. 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 (the “ Abney Action”), in which they allege, among other things, that ORM and other defendants engaged in the contamination of Florida waters and beaches in violation of Florida Statutes Chapter 376 and injured the Plaintiffs by exposing them to dispersants during the course and scope of their employment. The Abney Action 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.) (the “ Abood Action”), 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. The Abood Action was consolidated with the MDL on May 10, 2013. By court order, both of these matters were then stayed since they were consolidated with the MDL. The names of only a very small percentage of the claimants in these two matters appear to be listed on the exhibit to the Master MDL B3 Dismissal Order and the Court has denied the other plaintiffs’ request for reconsideration, which has since been appealed. In their appellate brief, filed in the U.S. Court of Appeals for the Fifth Circuit on June 15, 2018, these individual claimants noted that ORM “has been effectively dismissed through other actions by the lower court and that dismissal is not the subject of this appeal.” Accordingly, claimants concede that the original B3 Dismissal Order bars their claims against ORM. Finally, both the Abney Action and the Abood Action were directed closed by Court order dated September 9, 2018 (the “Close Out Order”). The Close Out Order similarly listed various individual actions that had been dismissed as against ORM and NRC by virtue of the B3 Dismissal Order and/or the Remaining Eleven Plaintiffs’ Dismissal Order. Separately, on March 2, 2012, the Court announced that BP Exploration and BP America Production Company (“BP America”) and (collectively “BP”) and the Plaintiffs had reached an agreement on the terms of two proposed class action settlements that will resolve, among other things, Plaintiffs’ economic loss claims and clean-up related claims against BP. The BP settlement pertaining to personal injury claims (the “Medical Settlement”) also established a right for class members to bring a lawsuit against BP (but not ORM or NRC) for later-manifested physical condition(s). These actions, referred to as back-end litigation-option (“BELO”) cases, have specifically-delineated procedures and limitations, as set forth in the Medical Settlement. For example, there are limitations on the claims and defenses that can be asserted, as well as on the issues, elements, and proofs that may be litigated at any trial and the potential recovery for any BELO plaintiff. Notwithstanding that the Company, ORM, and NRC are listed on the Medical Settlement’s release as to claims asserted by Plaintiffs, the Medical Settlement still permits BP to seek indemnity from any party, to the extent BP has a valid indemnity right. BP has purported to tender a number of individual BELO cases to ORM and/or NRC for indemnity pursuant to their service contracts with BP; as of close of business on September 30 2018, 101 BELO claims have been formally filed against BP that have been tendered to ORM and 14 BELO claims have been formally filed against BP that have been tendered to NRC. ORM and NRC have rejected BP’s contention that it is entitled to full defense and indemnity coverage from ORM and/or NRC for all of the BELO claims referenced in BP’s indemnity demands. Moreover, it is the Company’s position that (1) ORM has contractual indemnity coverage for the above-referenced BELO claims through its separate agreements with sub-contractors that worked for ORM during the Deepwater Horizon oil spill response and (2) NRC’s services contract with BP does not provide for broad contractual indemnity as BP contends. Discussions relating to these indemnity demands remain ongoing. Overall, however, the Company believes that both settlements, including the Medical Settlement, have reduced the potential exposure in connection with the various cases relating to the Deepwater Horizon oil spill response and clean-up. The Company is unable to estimate the potential exposure, if any, resulting from these claims but does not expect that they will have a material effect on its consolidated financial position, results of operations or cash flows. In the ordinary course of the Company’s business, it may agree to indemnify its 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, but not always, 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 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 B3 liabilities relating to cleanup work performed in connection with the Deepwater Horizon oil spill response; this indemnification is unrelated to, and thus not impacted by, the indemnification BP has demanded for the BELO cases referenced above. In the ordinary course of its business, the Company becomes involved in various other litigation matters including, among other things, claims by third parties for alleged property damages and personal injuries. Management has used estimates in determining the Company’s potential exposure to these matters and has recorded reserves in its financial statements related thereto where appropriate. It is possible that a change in the Company’s estimates of that exposure could occur, but the Company does not expect such changes in estimated costs would have a material effect on the Company’s consolidated financial position, results of operations or cash flows.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Segment Information	13. SEGMENT INFORMATION Accounting standards require public business enterprises to report information about each of their operating business segments that exceed certain quantitative thresholds or meet certain other reporting requirements. Operating business segments have been defined as components of an enterprise about which separate financial information is available and is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. Certain reclassifications and adjustments of prior period information have been made to conform the current period’s reportable segment presentation as a result of the Company’s presentation of discontinued operations and the adoption of Topic 606 (see Notes 1 and 14). The Company’s basis of measurement of segment profit or loss is as previously defined in the Company’s Annual report on Form 10-K for the year ended December 31, 2017 . Accounting standards also require companies to disaggregate revenues from contracts with customers into categories to depict how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. The following tables summarize the operating results, capital expenditures assets and disaggregated revenues of the Company’s reportable segments. Ocean Services $’000 Inland Services $’000 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the three months ended September 30, 2018 Operating Revenues: External customers 109,939 78,845 30,259 1,214 — 220,257 Intersegment — — 8 — (8 ) — 109,939 78,845 30,267 1,214 (8 ) 220,257 Costs and Expenses: Operating 64,683 65,667 16,240 957 (18 ) 147,529 Administrative and general 9,170 3,230 7,389 606 5,688 26,083 Depreciation and amortization 11,298 6,197 492 202 427 18,616 85,151 75,094 24,121 1,765 6,097 192,228 Gains on Asset Dispositions, Net 5,505 513 — — — 6,018 Operating Income (Loss) 30,293 4,264 6,146 (551 ) (6,105 ) 34,047 Other Income (Expense): Foreign currency losses, net (24 ) (282 ) (12 ) — (10 ) (328 ) Other, net (96 ) — — 452 1 357 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 2,073 (1,245 ) (13 ) 6 — 821 Segment Profit (Loss) 32,246 2,737 6,121 (93 ) Other Income (Expense) not included in Segment Profit (Loss) (4,332 ) Less Equity Earnings included in Segment Profit (Loss) (821 ) Income Before Taxes and Equity Earnings 29,744 Ocean Services $’000 Inland Services $’000 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the nine months ended September 30, 2018 Operating Revenues: External customers 317,478 208,175 93,960 2,299 — 621,912 Intersegment — — 47 — (47 ) — 317,478 208,175 94,007 2,299 (47 ) 621,912 Costs and Expenses: Operating 205,060 176,209 58,945 1,349 (89 ) 441,474 Administrative and general 30,047 9,758 17,896 1,290 17,198 76,189 Depreciation and amortization 35,563 18,674 1,284 264 1,284 57,069 270,670 204,641 78,125 2,903 18,393 574,732 Gains on Asset Dispositions, Net 7,391 6,178 — — — 13,569 Operating Income (Loss) 54,199 9,712 15,882 (604 ) (18,440 ) 60,749 Other Income (Expense): Foreign currency gains (losses), net (151 ) 238 (27 ) 1 (45 ) 16 Other, net 585 14 — 54,354 (2 ) 54,951 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 3,655 (3,115 ) 90 1,285 — 1,915 Segment Profit 58,288 6,849 15,945 55,036 Other Income (Expense) not included in Segment Profit (25,929 ) Less Equity Earnings included in Segment Profit (1,915 ) Income Before Taxes and Equity Earnings 89,787 Capital Expenditures 38,786 4,075 — 747 128 43,736 As of September 30, 2018 Property and Equipment: Historical cost 929,825 437,510 1,227 5,192 30,132 1,403,886 Accumulated depreciation (331,625 ) (190,493 ) (1,007 ) (265 ) (21,789 ) (545,179 ) Net property and equipment 598,200 247,017 220 4,927 8,343 858,707 Investments, at Equity, and Advances to 50% or Less Owned Companies 62,999 61,304 345 24,536 — 149,184 Inventories 2,509 2,258 214 158 — 5,139 Goodwill 1,852 2,409 28,506 — — 32,767 Intangible Assets 9,297 9,365 7,062 — — 25,724 Other current and long-term assets, excluding cash and near cash assets (1) 54,416 78,461 63,578 2,177 12,807 211,439 Segment Assets 729,273 400,814 99,925 31,798 Cash and near cash assets (1) 374,907 Total Assets 1,657,867 ______________________ (1) Cash and near cash assets includes cash, cash equivalents, restricted cash, restricted cash equivalents, marketable securities and construction reserve funds. Ocean Services $’000 Inland Services $’000 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the nine months ended September 30, 2018 Revenues from Contracts with Customers: Voyage charters 66,496 — — — — 66,496 Contracts of affreightment 9,101 159,406 — — — 168,507 Harbor & ocean towing 53,777 — — — — 53,777 Unit freight 43,384 — — — — 43,384 Terminal operations — 27,291 — — — 27,291 Fleeting operations — 13,325 — — — 13,325 Time and material contracts — — 84,896 — — 84,896 Retainer contracts — — 7,456 — — 7,456 Product sales (1) — — — 1,618 — 1,618 Other 2,414 2,618 1,655 425 (47 ) 7,065 Lease Revenues: Time charter, bareboat charter and rental income 142,306 5,535 — 256 — 148,097 317,478 208,175 94,007 2,299 (47 ) 621,912 ______________________ (1) Costs of goods sold related to product sales was $1.2 million . Ocean Services $’000 Inland Services $’000 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 As Adjusted As Adjusted For the three months ended September 30, 2017 Operating Revenues: External customers 103,780 63,042 9,667 116 — 176,605 Intersegment — — 14 — (14 ) — 103,780 63,042 9,681 116 (14 ) 176,605 Costs and Expenses: Operating 65,866 53,822 6,068 — (64 ) 125,692 Administrative and general 9,612 3,141 2,960 180 4,638 20,531 Depreciation and amortization 13,516 6,329 206 — 450 20,501 88,994 63,292 9,234 180 5,024 166,724 Gains on Asset Dispositions, Net 73 5,136 — — — 5,209 Operating Income (Loss) 14,859 4,886 447 (64 ) (5,038 ) 15,090 Other Income (Expense): Foreign currency gains (losses), net 5 992 29 (12 ) (45 ) 969 Other, net 59 — — — 5 64 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 1,493 (1,235 ) 100 130 — 488 Segment Profit 16,416 4,643 576 54 Other Income (Expense) not included in Segment Profit (19,229 ) Less Equity Earnings included in Segment Profit (488 ) Loss Before Taxes, Equity Earnings and Discontinued Operations (3,106 ) Ocean Services $’000 Inland Services $’000 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 As Adjusted As Adjusted For the nine months ended September 30, 2017 Operating Revenues: External customers 243,442 174,040 23,665 348 — 441,495 Intersegment — — 85 — (85 ) — 243,442 174,040 23,750 348 (85 ) 441,495 Costs and Expenses: Operating 137,070 148,978 15,483 — (256 ) 301,275 Administrative and general 24,728 11,658 8,641 559 23,363 68,949 Depreciation and amortization 32,792 19,404 613 — 1,880 54,689 194,590 180,040 24,737 559 24,987 424,913 Gains (Losses) on Asset Dispositions and Impairments, Net (342 ) 11,260 — — — 10,918 Operating Income (Loss) 48,510 5,260 (987 ) (211 ) (25,072 ) 27,500 Other Income (Expense): Derivative gains, net — — — — 19,727 19,727 Foreign currency gains (losses), net 8 730 62 (12 ) 110 898 Other, net 118 — — (300 ) 250 68 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 8,150 (4,877 ) 237 (581 ) — 2,929 Segment Profit (Loss) 56,786 1,113 (688 ) (1,104 ) Other Income (Expense) not included in Segment Profit (Loss) (37,860 ) Less Equity Earnings included in Segment Profit (Loss) (2,929 ) Income Before Taxes, Equity Earnings and Discontinued Operations 10,333 Capital Expenditures 66,137 32,901 60 — 208 99,306 As of September 30, 2017 Property and Equipment: Historical cost 1,028,685 446,759 1,227 — 29,532 1,506,203 Accumulated depreciation (290,400 ) (175,669 ) (915 ) — (20,065 ) (487,049 ) Net property and equipment 738,285 271,090 312 — 9,467 1,019,154 Investments, at Equity, and Advances to 50% or Less Owned Companies 53,388 65,738 782 55,479 — 175,387 Inventories 2,032 1,866 54 — — 3,952 Goodwill 1,852 2,415 28,506 — — 32,773 Intangible Assets 12,285 10,860 7,510 — — 30,655 Other current and long-term assets, excluding cash and near cash assets (1) 44,845 54,295 13,802 1,807 22,251 137,000 Segment Assets 852,687 406,264 50,966 57,286 Cash and near cash assets (1) 384,044 Total Assets 1,782,965 ______________________ (1) Cash and near cash assets includes cash, cash equivalents, restricted cash, restricted cash equivalents, marketable securities and construction reserve funds. Ocean Services $’000 Inland Services $’000 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 As Adjusted As Adjusted For the nine months ended September 30, 2017 Revenues from Contracts with Customers: Voyage charters 15,311 — — — — 15,311 Contracts of affreightment 9,315 130,770 — — — 140,085 Harbor & ocean towing 49,184 — — — — 49,184 Unit freight 36,763 — — — — 36,763 Terminal operations — 23,195 — — — 23,195 Fleeting operations — 11,654 — — — 11,654 Time and material contracts — — 11,887 — — 11,887 Retainer contracts — — 7,581 — — 7,581 Other 1,099 2,522 4,282 348 (85 ) 8,166 Lease Revenues: Time charter, bareboat charter and rental income 131,770 5,899 — — — 137,669 243,442 174,040 23,750 348 (85 ) 441,495

Discontinued Operations

Discontinued Operations	9 Months Ended
	Sep. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	14. DISCONTINUED OPERATIONS The Company’s discontinued operations consist of SEACOR Marine and ICP as following the Spin-off and sale, respectively, the Company has no continuing involvement in either of these businesses (see Note 1). Summarized selected operating results of the Company’s discontinued operations were as follows (in thousands): Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 SEACOR Marine Operating Revenues $ — $ 62,291 Costs and Expenses: Operating — 65,888 Administrative and general — 29,682 Depreciation and amortization — 22,181 — 117,751 Gains on Asset Dispositions, Net — 4,219 Operating Loss — (51,241 ) Other Income, Net — 1,780 Income Tax Benefit — (12,931 ) Equity in Earnings of 50% or Less Owned Companies, Net of Tax — 1,663 Net Loss $ — $ (34,867 ) Net Loss Attributable to Noncontrolling Interests $ — $ (1,892 ) ICP Operating Revenues $ — $ 78,061 Costs and Expenses: Operating — 76,306 Administrative and general — 2,109 Depreciation and amortization — 2,354 — 80,769 Operating Loss — (2,708 ) Other Income, Net (including gain on sale of business) 18,223 20,558 Income Tax Expense 7,296 7,363 Net Income $ 10,927 $ 10,487 Net Loss Attributable to Noncontrolling Interests $ — $ (539 ) Eliminations Operating Revenues $ — $ (1,176 ) Costs and Expenses: Operating — (1,289 ) Administrative and general — (42 ) — (1,331 ) Operating Income — 155 Other Income, Net — 1,738 Income Tax Expense — 663 Net Income $ — $ 1,230 Income (Loss) from Discontinued Operations, Net of Tax $ 10,927 $ (23,150 )

Basis of Presentation and Acc_2

Basis of Presentation and Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis Of Consolidation	The condensed consolidated financial information for the three and nine months ended September 30, 2018 and 2017 has been prepared by the Company and has not been audited by its independent registered certified public accounting firm. The condensed consolidated financial statements include the accounts of SEACOR Holdings Inc. and its consolidated subsidiaries. In the opinion of management, all adjustments (consisting of normal recurring adjustments) have been made to fairly present the Company’s financial position as of September 30, 2018 , its results of operations for the three and nine months ended September 30, 2018 and 2017 , its comprehensive income (loss) for the three and nine months ended September 30, 2018 and 2017 , its changes in equity for the nine months ended September 30, 2018 , and its cash flows for the nine months ended September 30, 2018 and 2017 . Results of operations for the interim periods presented are not necessarily indicative of operating results for the full year or any future periods. Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States have been condensed or omitted. These condensed consolidated financial statements should be read in conjunction with the financial statements and related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 . Unless the context otherwise indicates, any reference in this Quarterly Report on Form 10-Q to the “Company” refers to SEACOR Holdings Inc. and its consolidated subsidiaries and any reference in this Quarterly Report on Form 10-Q to “SEACOR” refers to SEACOR Holdings Inc. without its consolidated subsidiaries. Capitalized terms used and not specifically defined herein have the same meaning given those terms in the Company's Annual report on Form 10-K for the year ended December 31, 2017 .
New Accounting Pronouncements	New Accounting Pronouncements. On February 25, 2016, the FASB issued a comprehensive new leasing standard that is meant to improve transparency and comparability among companies by requiring lessees to recognize a lease liability and a corresponding lease asset for virtually all lease contracts and also requires additional disclosures about leasing arrangements. The new standard is effective for interim and annual periods beginning after December 15, 2018. The Company will adopt this standard using a modified prospective approach to adoption with recognition of a cumulative-effect adjustment to the opening balance of retained earnings at the adoption date. The Company is in the process of preparing for implementation and currently believes that the adoption will have a material impact on its financial statements. Specifically, the Company will be recording material right-of-use assets and lease liabilities of approximately $150 - $175 million for certain of its equipment, office and land leases. The Company’s estimates are preliminary and are based on its current inventory of leases. If the Company enters into or exits material lease arrangements prior to adoption or makes material changes to certain of its assumptions, including lease discount rates, the Company’s estimates may change and those changes may be material. On January 26, 2017, the FASB issued an amendment to the accounting standards, which simplified wording and removed step two of the goodwill impairment test. A goodwill impairment will now be the amount by which a reporting unit’s 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. Adoption of New Accounting Standards. On January 1, 2018, the Company adopted Financial Accounting Standard Board (“FASB”) Topic 606, Revenue from Contracts with Customers (“Topic 606”). As a consequence of adopting Topic 606, the Company now recognizes all of the operating revenues and expenses associated with the dry-cargo barge pools it manages along with additional operating expenses reflective of barge pool earnings attributable to third-party barge owners and not the Company in its capacity as manager. Under Topic 606, the Company determined it was a principal with respect to the third-party barge owners. Previously, the Company recognized operating revenues and expenses only for its proportionate share of the barge pools in which it participated, as it acted as an agent. All prior period results have been adjusted to reflect the retrospective adoption of Topic 606. The adoption of Topic 606 had no impact on previously reported operating income, net income or earnings per share. On January 1, 2018, the Company adopted ASU 2016-16, Intra-Entity Transfers of Assets Other Than Inventory , which eliminates the deferral of the tax effects of intercompany asset sales other than inventory until the transferred assets are sold to a third party or recovered through use. As a result of the adoption of the standard, the deferred tax charges previously recognized from those sales resulted in a decrease in deferred tax assets and a cumulative adjustment to retained earnings of $2.5 million in the condensed consolidated balance sheet and statement of changes in equity as of January 1, 2018.
Discontinued Operations	Discontinued Operations. On June 1, 2017, the Company completed the spin-off of SEACOR Marine Holdings Inc. (“SEACOR Marine”), the company that operated SEACOR’s Offshore Marine Services business segment, by means of a dividend of all the issued and outstanding common stock of SEACOR Marine to SEACOR’s shareholders (the “Spin-off”). SEACOR Marine is now an independent company whose common stock is listed on the New York Stock Exchange under the symbol “SMHI.” For all periods presented herein, the Company has reported the historical financial position, results of operations and cash flows of SEACOR Marine as discontinued operations (see Note 14). On July 3, 2017, the Company completed the sale of its 70% interest in Illinois Corn Processing LLC (“ICP”), the company that operated SEACOR’s Illinois Corn Processing business segment. For all periods presented herein, the Company has reported the historical financial position, results of operations and cash flows of ICP as discontinued operations (see Note 14).
Revenue Recognition	Revenue Recognition. Revenue is recognized when (or as) the Company transfers promised goods or services to its customers in amounts that reflect the consideration to which the Company expects to be entitled to in exchange for those goods or services, which occurs when (or as) the Company satisfies its contractual obligations and transfers control of the promised goods or services to its customers. Costs to obtain or fulfill a contract are expensed as incurred. Revenue from Contracts with Customers. Ocean Services primarily earns revenues from voyage charters, contracts of affreightment, harbor and ocean towing services, unit freight transportation services and technical ship management agreements with vessel owners (see Note 13). Ocean Services transfers control of the service to the customer and satisfies its performance obligation over the term of the contract, and therefore recognizes revenue over the term of the contract while related costs are expensed as incurred. Voyage charters are contracts to carry cargoes on a single voyage basis for a predetermined price, 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. Harbor and ocean towing services typically include operating harbor tugs alongside oceangoing vessels to escort them to their berth, assisting with the docking and undocking of these oceangoing vessels and escorting them back out to sea. They are contracted using prevailing port tariff terms on a per-use basis. In the unit freight trade, transportation services typically include transporting shipping containers, rail cars, project cargoes, automobiles and U.S. military vehicles and are generally contracted on a per unit basis for the specified cargo and destination, typically in accordance with a publicly available tariff rate or based on a negotiated rate when moving larger volumes over an extended period. Other operations primarily include technical ship management agreements whereby Ocean Services provides technical ship management services to third-party customers for a predetermined price over a specified period of time, typically a year or more. Inland Services primarily earns revenues from contracts of affreightment, terminal operations, fleeting operations and repair and maintenance services (see Note 13). Inland Services transfers control of the service to the customer and satisfies its performance obligation over the term of the contract, and therefore recognizes revenue over the term of the contract while related costs are expensed as incurred. Contracts of affreightment are contracts whereby customers are charged an established rate per ton to transport cargo from point-to-point. Terminal operations includes tank farms and dry bulk and container handling facilities that are marketed under contractual rates and terms driven by throughput volume. Fleeting operations includes fleeting services whereby barges are held in fleeting areas for an agreed-upon day rate and shifting services whereby harbor boats are used to pick up and drop off barges to assist in assembling tows and to move barges to and from the dock for loading and unloading at predetermined per-shift fees. Other operations primarily include a machine shop specializing in towboat and barge cleaning, repair and maintenance services that are charged on an hourly or a fixed fee basis depending on the scope and nature of the work. Witt O’Brien’s primarily earns revenues from time and material and retainer contracts (see Note 13). Witt O’Brien’s transfers control of the service to the customer and satisfies its performance obligation over the term of the contract, and therefore recognizes revenue over the term of the contract while related costs are expensed as incurred. Time and material contracts primarily relate to emergency response, debris management or consulting services that Witt O’Brien’s performs for a predetermined fee. Retainer contracts, which are nearly all with vessel services operators and oil companies, are contracted based on agreed-upon rates. The Company’s Other business segment includes CLEANCOR Energy Solutions LLC (“Cleancor”) (see Note 2). Cleancor primarily earns revenues from the sale of liquefied natural gas (see Note 13). Under these arrangements, control of the goods are transfered to the customer and performance obligations are satisfied at a point in time, and therefore revenue is recognized upon delivery while any related costs are expensed as incurred. Contract liabilities from contracts with customers arise when the Company has received consideration prior to performance and are included in other current liabilities in the accompanying condensed consolidated balance sheets.
Lease Revenues	Lease Revenues. The Company’s lease revenues are primarily from time charters, bareboat charters and non-vessel rental agreements that are recognized ratably over the lease term as services are provided, typically on a per day basis. Under a time charter, the Company provides a vessel to a customer for a set term and is responsible for all operating expenses, typically excluding fuel. Under a bareboat charter, the Company provides a vessel to a customer for a set term and the customer assumes responsibility for all operating expenses and risks of operation. Under a non-vessel rental agreement, the Company provides non-vessel property or equipment to a customer for a set term and the customer assumes responsibility for all operating expenses and risks of operation.
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 based upon a newly built asset being placed into service and represents the time period beyond which it is typically not justifiable for the Company to continue to operate the asset in the same or similar manner. From time to time, the Company may acquire older assets that have already exceeded their useful life as set forth in the Company’s useful life policy, in which case the Company depreciates such assets based on its best estimate of remaining useful life, typically the next survey or certification date. As of September 30, 2018 , the estimated useful life (in years) of each of the Company’s major categories of new equipment was as follows: Petroleum and chemical carriers - U.S.-flag 25 Harbor and offshore tugs 25 Ocean liquid tank barges 25 Short-sea container/RORO (1) vessels 20 Dry bulk carriers - U.S.-flag 25 Inland river dry-cargo and specialty barges 20 Inland river liquid tank barges 25 Inland river towboats and harbor boats 25 Terminal and fleeting facilities 20 ______________________ (1) Roll On/Roll Off. Equipment maintenance and repair costs including the costs of routine overhauls, dry-dockings 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. As of September 30, 2018 , the Company’s construction in progress totaling $4.6 million primarily consisted of upgrades to inland river towboats and the construction of other Inland Services equipment, and is included in historical cost in the accompanying condensed consolidated balance sheets. Certain interest costs incurred during the construction of equipment are capitalized as part of the assets’ carrying values and are amortized over such assets’ estimated useful lives. During the nine months ended September 30, 2018 , capitalized interest totaled $0.2 million .
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 value and impairment charges are recorded if the carrying value exceeds fair value. The Company performs its testing on an asset or asset group basis. The Company’s estimates of undiscounted cash flows are highly subjective and actual results may vary from the Company’s estimates due to the uncertainty regarding projected financial performance. Generally, fair value is determined using valuation techniques, such as expected discounted cash flows or appraisals, as appropriate. During the nine months ended September 30, 2018 , the Company did not recognize any impairment charges related to long-lived assets held for use.
Impairment of 50% or Less Owned Companies	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.
Income Taxes	Income Taxes. During the nine months ended September 30, 2018 , the Company’s effective income tax rate of 14.4% was primarily due to foreign sourced income not subject to U.S. tax partially offset by income taxes on Subpart F income (see Note 6).
Deferred Gains	Deferred Gains. The Company has sold certain equipment to its 50% or less owned companies, entered into vessel sale-leaseback transactions with finance companies, and provided seller financing on sales of its equipment to third parties and its 50% or less owned companies. A portion of the gains realized from these transactions were deferred and recorded in deferred gains and other liabilities in the accompanying condensed consolidated balance sheets.
Earnings Per Share	Earnings Per Share. Basic earnings per common share of SEACOR is computed based on the weighted average number of common shares issued and outstanding during the relevant periods. Diluted earnings per common share of SEACOR is computed based on the weighted average number of common shares issued and outstanding plus the effect of potentially dilutive securities through the application of the treasury stock and if-converted methods. Dilutive securities for this purpose assumes restricted stock grants have vested, common shares have been issued pursuant to the exercise of outstanding stock options and common shares have been issued pursuant to the conversion of all outstanding convertible notes.

Basis of Presentation and Acc_3

Basis of Presentation and Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Contract with Customer, Asset and Liability	The Company’s contract liability activity for the nine months ended September 30 was as follows (in thousands): 2018 Balance at beginning of period $ 983 Contract liabilities arising during the period 4,374 Revenue recognized upon completion of performance obligations during the period (2,291 ) Balance at end of period $ 3,066
Property, Plant and Equipment	As of September 30, 2018 , the estimated useful life (in years) of each of the Company’s major categories of new equipment was as follows: Petroleum and chemical carriers - U.S.-flag 25 Harbor and offshore tugs 25 Ocean liquid tank barges 25 Short-sea container/RORO (1) vessels 20 Dry bulk carriers - U.S.-flag 25 Inland river dry-cargo and specialty barges 20 Inland river liquid tank barges 25 Inland river towboats and harbor boats 25 Terminal and fleeting facilities 20 ______________________ (1) Roll On/Roll Off.
Schedule Of Deferred Gain Activity	Deferred gain activity related to these transactions for the nine months ended September 30 was as follows (in thousands): 2018 2017 Balance at beginning of period $ 72,453 $ 82,423 Deferred gains arising from asset sales — 7,720 Amortization of deferred gains included in operating expenses as a reduction to rental expense (8,991 ) (11,126 ) Amortization of deferred gains included in gains on asset dispositions and impairments, net (1) (6,988 ) (1,764 ) Reclassification of deferred gains into historical cost on reacquired property and equipment (3,052 ) — Balance at end of period $ 53,422 $ 77,253 ______________________ (1) For the nine months ended September 30, 2018 , the Company recognized previously deferred gains of $5.5 million due to a change in the lease duration for one U.S.-flag petroleum and chemical carrier.
Schedule of Earnings Per Share, Basic and Diluted	Computations of basic and diluted earnings per common share of SEACOR were as follows (in thousands, except share data): Three Months Ended September 30, Nine Months Ended September 30, Net Income attributable to SEACOR Average O/S Shares Per Share Net Income (Loss) Attributable to SEACOR Average O/S Shares Per Share 2018 Basic Weighted Average Common Shares Outstanding $ 17,067 18,108,388 $ 0.94 $ 62,834 18,052,274 $ 3.48 Effect of Dilutive Share Awards: Options and Restricted Stock (1) — 303,285 — 299,405 Convertible Notes (2) 1,625 2,780,881 9,495 4,156,943 Diluted Weighted Average Common Shares Outstanding $ 18,692 21,192,554 $ 0.88 $ 72,329 22,508,622 $ 3.21 2017 Basic Weighted Average Common Shares Outstanding $ 17,561 17,508,770 $ 1.00 $ (11,164 ) 17,265,140 $ (0.65 ) Effect of Dilutive Share Awards: Options and Restricted Stock (3) — 129,054 — 245,420 Convertible Notes (4) — — — — Diluted Weighted Average Common Shares Outstanding $ 17,561 17,637,824 $ 1.00 $ (11,164 ) 17,510,560 $ (0.64 ) ______________________ (1) For the three and nine months ended September 30, 2018 , diluted earnings per common share of SEACOR excluded 295,074 and 292,169 , respectively, of certain share awards as the effect of their inclusion in the computation would be anti-dilutive. (2) For the three months ended September 30, 2018 , diluted earnings per common share of SEACOR excluded 1,408,719 of common shares issuable pursuant to the Company’s 3.0% Convertible Senior Notes as the effect of their inclusion in the computation would be anti-dilutive. (3) For the three and nine months ended September 30, 2017 , diluted earnings per common share of SEACOR excluded 1,727,132 and 2,638,753 , respectively, of certain share awards as the effect of their inclusion in the computation would be anti-dilutive. Diluted weighted average shares outstanding are calculated based on continuing operations. (4) For the three and nine months ended September 30, 2017 , diluted earnings per common share of SEACOR excluded 1,889,027 and 2,488,460 , respectively, of common shares issuable pursuant to the Company’s 2.5% Convertible Senior Notes and 2,801,147 and 2,801,147 , respectively, of common shares issuable pursuant to the Company’s 3.0% Convertible Senior Notes as the effect of their inclusion in the computation would be anti-dilutive. Diluted weighted average shares outstanding are calculated based on continuing operations.

Business Acquisitions (Tables)

Business Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The allocation of the purchase price for the Company’s acquisitions for the nine months ended September 30, 2018 was as follows (in thousands): Trade and other receivables $ 1,264 Other current assets 170 Investments, at Equity, and Advances to 50% or Less Owned Companies (3,219 ) Property and Equipment 4,382 Intangible Assets 950 Notes receivable contributed as equity (1,904 ) Other Assets 7 Accounts payable and other accrued liabilities (1) (1,609 ) Other current liabilities (269 ) Noncontrolling interests in subsidiaries (82 ) Purchase price (2) $ (310 ) ______________________ (1) Includes $1.3 million of consideration to be paid in two installments. (2) Purchase price is net of cash acquired totaling $3.6 million

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Schedule 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 on continuing operations for the nine months ended September 30, 2018 : Statutory rate 21.0 % Income subject to tonnage tax (2.4 )% Noncontrolling interests (3.7 )% Foreign earnings not subject to U.S. income tax (17.7 )% Foreign taxes not creditable against U.S. income tax 4.1 % Subpart F income 12.3 % State taxes 0.7 % Other 0.1 % 14.4 %

Derivative Instruments and He_2

Derivative Instruments and Hedging Strategies (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives Not Designated as Hedging Instruments	The Company recognized gains on derivative instruments not designated as hedging instruments for the nine months ended September 30 as follows (in thousands): 2018 2017 Exchange option liability on subsidiary convertible senior notes $ — $ 19,436 Forward currency exchange, option and future contracts — 291 $ — $ 19,727

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The Company’s financial assets and liabilities as of September 30, 2018 that are measured at fair value on a recurring basis were as follows (in thousands): Level 1 Level 2 Level 3 ASSETS Cash, cash equivalents, restricted cash and restricted cash equivalents $ 327,554 $ — $ — Marketable securities (1) 41,445 — — Construction reserve funds 5,908 — — ______________________ (1) Marketable security gains (losses), net include unrealized gains of $1.7 million and unrealized losses of $7.1 million for the three months ended September 30, 2018 and 2017 , respectively, related to marketable security positions held by the Company as of September 30, 2018 . Marketable security gains (losses), net include unrealized losses of $1.3 million and $7.2 million for the nine months ended September 30, 2018 and 2017 , respectively, related to marketable security positions held by the Company as of September 30, 2018 .
Estimated Fair Value Of Other Financial Assets And Liabilities	The estimated fair values of the Company’s other financial assets and liabilities as of September 30, 2018 were as follows (in thousands): Estimated Fair Value Carrying Amount Level 1 Level 2 Level 3 ASSETS Notes receivable from third parties (included in other receivables and other assets) $ 2,226 $ — $ 2,203 $ — Investments, at cost, in 50% or less owned companies (included in other assets) 4,300 see below LIABILITIES Long-term debt, including current portion (1) $ 528,394 $ — $ 561,044 $ — ______________________ (1) The estimated fair value includes the embedded conversion options on the Company’s 3.0% Convertible Senior Notes and 3.25% Convertible Senior Notes.
Fair Value Measurements, Nonrecurring	The Company’s other assets and liabilities that were measured at fair value during the nine months ended September 30, 2018 were as follows (in thousands): Level 1 Level 2 Level 3 ASSETS Investments, at equity, and advances in 50% or less owned companies $ — $ 3,219 $ — Investments, at equity, and advances in 50% or less owned companies. During the nine months ended September 30, 2018 , the Company marked its investment in Cleancor to fair value as a consequence of the Company acquiring its partners’ 50% interest, resulting in a gain of $0.1 million , net of tax, based on the fair value of the acquired interest (see Note 2). In addition, during the nine months ended September 30, 2018 , the Company identified indicators of impairment in one of its 50% or less owned companies and, as a consequence, recognized an impairment charge of $0.1 million for an other-than-temporary decline in fair value. The investment was determined to have an immaterial value.

Noncontrolling Interests in S_2

Noncontrolling Interests in Subsidiaries (Tables)	9 Months Ended
	Sep. 30, 2018
Noncontrolling Interest [Abstract]
Noncontrolling Interests in Subsidiaries	Noncontrolling interests in the Company’s consolidated subsidiaries were as follows (in thousands): Noncontrolling Interests September 30, 2018 December 31, 2017 Ocean Services: SEA-Vista 49% $ 139,566 $ 128,550 Inland Services: Other 3.0 % – 51.8% 841 977 Other 5.0 % – 11.8% 190 151 $ 140,597 $ 129,678

Share Based Compensation (Table

Share Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share Based Compensation Plans	Transactions in connection with the Company’s share based compensation plans during the nine months ended September 30, 2018 were as follows: Director stock awards granted 2,250 Employee Stock Purchase Plan (“ESPP”) shares issued 45,251 Restricted stock awards granted 121,850 Stock Option Activities: Outstanding as of December 31, 2017 1,546,014 Granted 110,660 Exercised (134,212 ) Outstanding as of September 30, 2018 1,522,462 Shares available for future grants and ESPP purchases as of September 30, 2018 916,254

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Unrecorded Unconditional Purchase Obligations Disclosure	The Company's capital commitments as of September 30, 2018 by year of expected payment were as follows (in thousands): Remainder of 2018 2019 Total Ocean Services $ 106 $ — $ 106 Inland Services 2,478 2,690 5,168 $ 2,584 $ 2,690 $ 5,274

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Operating Results, Capital Expenditures And Assets By Reporting Segment	Ocean Services $’000 Inland Services $’000 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 As Adjusted As Adjusted For the three months ended September 30, 2017 Operating Revenues: External customers 103,780 63,042 9,667 116 — 176,605 Intersegment — — 14 — (14 ) — 103,780 63,042 9,681 116 (14 ) 176,605 Costs and Expenses: Operating 65,866 53,822 6,068 — (64 ) 125,692 Administrative and general 9,612 3,141 2,960 180 4,638 20,531 Depreciation and amortization 13,516 6,329 206 — 450 20,501 88,994 63,292 9,234 180 5,024 166,724 Gains on Asset Dispositions, Net 73 5,136 — — — 5,209 Operating Income (Loss) 14,859 4,886 447 (64 ) (5,038 ) 15,090 Other Income (Expense): Foreign currency gains (losses), net 5 992 29 (12 ) (45 ) 969 Other, net 59 — — — 5 64 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 1,493 (1,235 ) 100 130 — 488 Segment Profit 16,416 4,643 576 54 Other Income (Expense) not included in Segment Profit (19,229 ) Less Equity Earnings included in Segment Profit (488 ) Loss Before Taxes, Equity Earnings and Discontinued Operations (3,106 ) Ocean Services $’000 Inland Services $’000 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 As Adjusted As Adjusted For the nine months ended September 30, 2017 Operating Revenues: External customers 243,442 174,040 23,665 348 — 441,495 Intersegment — — 85 — (85 ) — 243,442 174,040 23,750 348 (85 ) 441,495 Costs and Expenses: Operating 137,070 148,978 15,483 — (256 ) 301,275 Administrative and general 24,728 11,658 8,641 559 23,363 68,949 Depreciation and amortization 32,792 19,404 613 — 1,880 54,689 194,590 180,040 24,737 559 24,987 424,913 Gains (Losses) on Asset Dispositions and Impairments, Net (342 ) 11,260 — — — 10,918 Operating Income (Loss) 48,510 5,260 (987 ) (211 ) (25,072 ) 27,500 Other Income (Expense): Derivative gains, net — — — — 19,727 19,727 Foreign currency gains (losses), net 8 730 62 (12 ) 110 898 Other, net 118 — — (300 ) 250 68 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 8,150 (4,877 ) 237 (581 ) — 2,929 Segment Profit (Loss) 56,786 1,113 (688 ) (1,104 ) Other Income (Expense) not included in Segment Profit (Loss) (37,860 ) Less Equity Earnings included in Segment Profit (Loss) (2,929 ) Income Before Taxes, Equity Earnings and Discontinued Operations 10,333 Capital Expenditures 66,137 32,901 60 — 208 99,306 As of September 30, 2017 Property and Equipment: Historical cost 1,028,685 446,759 1,227 — 29,532 1,506,203 Accumulated depreciation (290,400 ) (175,669 ) (915 ) — (20,065 ) (487,049 ) Net property and equipment 738,285 271,090 312 — 9,467 1,019,154 Investments, at Equity, and Advances to 50% or Less Owned Companies 53,388 65,738 782 55,479 — 175,387 Inventories 2,032 1,866 54 — — 3,952 Goodwill 1,852 2,415 28,506 — — 32,773 Intangible Assets 12,285 10,860 7,510 — — 30,655 Other current and long-term assets, excluding cash and near cash assets (1) 44,845 54,295 13,802 1,807 22,251 137,000 Segment Assets 852,687 406,264 50,966 57,286 Cash and near cash assets (1) 384,044 Total Assets 1,782,965 ______________________ (1) Cash and near cash assets includes cash, cash equivalents, restricted cash, restricted cash equivalents, marketable securities and construction reserve funds. The following tables summarize the operating results, capital expenditures assets and disaggregated revenues of the Company’s reportable segments. Ocean Services $’000 Inland Services $’000 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the three months ended September 30, 2018 Operating Revenues: External customers 109,939 78,845 30,259 1,214 — 220,257 Intersegment — — 8 — (8 ) — 109,939 78,845 30,267 1,214 (8 ) 220,257 Costs and Expenses: Operating 64,683 65,667 16,240 957 (18 ) 147,529 Administrative and general 9,170 3,230 7,389 606 5,688 26,083 Depreciation and amortization 11,298 6,197 492 202 427 18,616 85,151 75,094 24,121 1,765 6,097 192,228 Gains on Asset Dispositions, Net 5,505 513 — — — 6,018 Operating Income (Loss) 30,293 4,264 6,146 (551 ) (6,105 ) 34,047 Other Income (Expense): Foreign currency losses, net (24 ) (282 ) (12 ) — (10 ) (328 ) Other, net (96 ) — — 452 1 357 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 2,073 (1,245 ) (13 ) 6 — 821 Segment Profit (Loss) 32,246 2,737 6,121 (93 ) Other Income (Expense) not included in Segment Profit (Loss) (4,332 ) Less Equity Earnings included in Segment Profit (Loss) (821 ) Income Before Taxes and Equity Earnings 29,744 Ocean Services $’000 Inland Services $’000 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the nine months ended September 30, 2018 Operating Revenues: External customers 317,478 208,175 93,960 2,299 — 621,912 Intersegment — — 47 — (47 ) — 317,478 208,175 94,007 2,299 (47 ) 621,912 Costs and Expenses: Operating 205,060 176,209 58,945 1,349 (89 ) 441,474 Administrative and general 30,047 9,758 17,896 1,290 17,198 76,189 Depreciation and amortization 35,563 18,674 1,284 264 1,284 57,069 270,670 204,641 78,125 2,903 18,393 574,732 Gains on Asset Dispositions, Net 7,391 6,178 — — — 13,569 Operating Income (Loss) 54,199 9,712 15,882 (604 ) (18,440 ) 60,749 Other Income (Expense): Foreign currency gains (losses), net (151 ) 238 (27 ) 1 (45 ) 16 Other, net 585 14 — 54,354 (2 ) 54,951 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 3,655 (3,115 ) 90 1,285 — 1,915 Segment Profit 58,288 6,849 15,945 55,036 Other Income (Expense) not included in Segment Profit (25,929 ) Less Equity Earnings included in Segment Profit (1,915 ) Income Before Taxes and Equity Earnings 89,787 Capital Expenditures 38,786 4,075 — 747 128 43,736 As of September 30, 2018 Property and Equipment: Historical cost 929,825 437,510 1,227 5,192 30,132 1,403,886 Accumulated depreciation (331,625 ) (190,493 ) (1,007 ) (265 ) (21,789 ) (545,179 ) Net property and equipment 598,200 247,017 220 4,927 8,343 858,707 Investments, at Equity, and Advances to 50% or Less Owned Companies 62,999 61,304 345 24,536 — 149,184 Inventories 2,509 2,258 214 158 — 5,139 Goodwill 1,852 2,409 28,506 — — 32,767 Intangible Assets 9,297 9,365 7,062 — — 25,724 Other current and long-term assets, excluding cash and near cash assets (1) 54,416 78,461 63,578 2,177 12,807 211,439 Segment Assets 729,273 400,814 99,925 31,798 Cash and near cash assets (1) 374,907 Total Assets 1,657,867 ______________________ (1) Cash and near cash assets includes cash, cash equivalents, restricted cash, restricted cash equivalents, marketable securities and construction reserve funds.
Disaggregation of Revenue	Ocean Services $’000 Inland Services $’000 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 For the nine months ended September 30, 2018 Revenues from Contracts with Customers: Voyage charters 66,496 — — — — 66,496 Contracts of affreightment 9,101 159,406 — — — 168,507 Harbor & ocean towing 53,777 — — — — 53,777 Unit freight 43,384 — — — — 43,384 Terminal operations — 27,291 — — — 27,291 Fleeting operations — 13,325 — — — 13,325 Time and material contracts — — 84,896 — — 84,896 Retainer contracts — — 7,456 — — 7,456 Product sales (1) — — — 1,618 — 1,618 Other 2,414 2,618 1,655 425 (47 ) 7,065 Lease Revenues: Time charter, bareboat charter and rental income 142,306 5,535 — 256 — 148,097 317,478 208,175 94,007 2,299 (47 ) 621,912 ______________________ (1) Costs of goods sold related to product sales was $1.2 million . Ocean Services $’000 Inland Services $’000 Witt O’Brien’s $’000 Other $’000 Corporate and Eliminations $’000 Total $’000 As Adjusted As Adjusted For the nine months ended September 30, 2017 Revenues from Contracts with Customers: Voyage charters 15,311 — — — — 15,311 Contracts of affreightment 9,315 130,770 — — — 140,085 Harbor & ocean towing 49,184 — — — — 49,184 Unit freight 36,763 — — — — 36,763 Terminal operations — 23,195 — — — 23,195 Fleeting operations — 11,654 — — — 11,654 Time and material contracts — — 11,887 — — 11,887 Retainer contracts — — 7,581 — — 7,581 Other 1,099 2,522 4,282 348 (85 ) 8,166 Lease Revenues: Time charter, bareboat charter and rental income 131,770 5,899 — — — 137,669 243,442 174,040 23,750 348 (85 ) 441,495

Discontinued Operations (Tables

Discontinued Operations (Tables)	9 Months Ended
	Sep. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
Disposal Groups, Including Discontinued Operations	Summarized selected operating results of the Company’s discontinued operations were as follows (in thousands): Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 SEACOR Marine Operating Revenues $ — $ 62,291 Costs and Expenses: Operating — 65,888 Administrative and general — 29,682 Depreciation and amortization — 22,181 — 117,751 Gains on Asset Dispositions, Net — 4,219 Operating Loss — (51,241 ) Other Income, Net — 1,780 Income Tax Benefit — (12,931 ) Equity in Earnings of 50% or Less Owned Companies, Net of Tax — 1,663 Net Loss $ — $ (34,867 ) Net Loss Attributable to Noncontrolling Interests $ — $ (1,892 ) ICP Operating Revenues $ — $ 78,061 Costs and Expenses: Operating — 76,306 Administrative and general — 2,109 Depreciation and amortization — 2,354 — 80,769 Operating Loss — (2,708 ) Other Income, Net (including gain on sale of business) 18,223 20,558 Income Tax Expense 7,296 7,363 Net Income $ 10,927 $ 10,487 Net Loss Attributable to Noncontrolling Interests $ — $ (539 ) Eliminations Operating Revenues $ — $ (1,176 ) Costs and Expenses: Operating — (1,289 ) Administrative and general — (42 ) — (1,331 ) Operating Income — 155 Other Income, Net — 1,738 Income Tax Expense — 663 Net Income $ — $ 1,230 Income (Loss) from Discontinued Operations, Net of Tax $ 10,927 $ (23,150 )

Basis of Presentation and Acc_4

Basis of Presentation and Accounting Policies - Adoption of New Accounting Standards (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle in period of adoption		$ (2,467)
Accounting Standards Update 2016-16
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred income tax assets, net		(2,500)
Accounting Standards Update 2016-16 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle in period of adoption		$ (2,467)
Minimum | Subsequent Event | Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New accounting pronouncement or change in accounting principle, effect of adoption, quantification	$ 150,000
Maximum | Subsequent Event | Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New accounting pronouncement or change in accounting principle, effect of adoption, quantification	$ 175,000

Basis of Presentation and Acc_5

Basis of Presentation and Accounting Policies - Discontinued Operations (Details)	Jul. 03, 2017
Illinois Corn Processing LLC
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncontrolling interest, ownership percentage by parent	70.00%

Basis of Presentation and Acc_6

Basis of Presentation and Accounting Policies - Revenue Recognition (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Change in Contract with Customer, Liability [Roll Forward]
Balance at beginning of period	$ 983
Contract liabilities arising during the period	4,374
Revenue recognized upon completion of performance obligations during the period	(2,291)
Balance at end of period	$ 3,066

Basis of Presentation and Acc_7

Basis of Presentation and Accounting Policies - Property and Equipment (Details) $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)
Property, Plant and Equipment [Line Items]
Construction in progress	$ 4.6
Interest costs capitalized	$ 0.2
U.S.-flag Petroleum and Chemical Carrier
Property, Plant and Equipment [Line Items]
Useful life	25 years
Harbor and Offshore Tugs
Property, Plant and Equipment [Line Items]
Useful life	25 years
Ocean Liquid Tank Barge
Property, Plant and Equipment [Line Items]
Useful life	25 years
Short-sea Container/RORO Vessels
Property, Plant and Equipment [Line Items]
Useful life	20 years
U.S.-flag dry-bulk carrier
Property, Plant and Equipment [Line Items]
Useful life	25 years
Inland River Dry Cargo and Deck Barges
Property, Plant and Equipment [Line Items]
Useful life	20 years
Inland River Liquid Tank Barges
Property, Plant and Equipment [Line Items]
Useful life	25 years
Inland River Towboats
Property, Plant and Equipment [Line Items]
Useful life	25 years
Terminal And Manufacturing Facilities
Property, Plant and Equipment [Line Items]
Useful life	20 years

Basis of Presentation and Acc_8

Basis of Presentation and Accounting Policies - Impairments of Long-Lived Assets (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Accounting Policies [Abstract]
Asset impairment charges		$ 0.4
Other Corporate Equity Method Investments
Schedule Of Equity Method Investments [Line Items]
Impairment charge for an other-than-temporary decline in fair value	$ 0.1	$ 0.9

Basis of Presentation and Acc_9

Basis of Presentation and Accounting Policies - Income Taxes (Details)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Effective income tax rate reconciliation, percent	14.40%

Basis of Presentation and Ac_10

Basis of Presentation and Accounting Policies - Deferred Gains (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Deferred Gains [Roll Forward]
Balance at beginning of period	$ 72,453	$ 82,423
Deferred gains arising from asset sales	0	7,720
Reclassification of deferred gains into historical cost on reacquired property and equipment	(3,052)	0
Balance at end of period	53,422	77,253
Operating Expense
Deferred Gains [Roll Forward]
Amortization of deferred gains	(8,991)	(11,126)
Gain on Asset Dispositions and Impairments, Net
Deferred Gains [Roll Forward]
Amortization of deferred gains	(6,988)	$ (1,764)
U.S.-flag Petroleum and Chemical Carrier | Gain on Asset Dispositions and Impairments, Net
Deferred Gains [Roll Forward]
Amortization of deferred gains	$ (5,500)

Basis of Presentation and Ac_11

Basis of Presentation and Accounting Policies - Earning Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss) attributable to SEACOR Holdings Inc.	$ 17,067	$ 17,561	$ 62,834	$ (11,164)
Effect of Dilutive Share Awards:
Options and Restricted Stock	0	0	0	0
Convertible Notes	1,625	0	9,495	0
Net income (loss) attributable to SEACOR, diluted	$ 18,692	$ 17,561	$ 72,329	$ (11,164)
Basic weighted average common shares outstanding (in shares)	18,108,388	17,508,770	18,052,274	17,265,140
Effect of Dilutive Share Awards:
Options and Restricted Stock (in shares)	303,285	129,054	299,405	245,420
Convertible Notes (in shares)	2,780,881	0	4,156,943	0
Diluted weighted averages common shares outstanding (in shares)	21,192,554	17,637,824	22,508,622	17,510,560
Basic earnings per share (in dollars per share)	$ 0.94	$ 1	$ 3.48	$ (0.65)
Diluted earnings per share (in dollars per share)	$ 0.88	$ 1	$ 3.21	$ (0.64)
Stock Compensation Plan
Effect of Dilutive Share Awards:
Anti-dilutive securities (in shares)	295,074	1,727,132	292,169	2,638,753
Two Point Five Percentage Convertible Notes
Effect of Dilutive Share Awards:
Debt instrument, interest rate, stated percentage	2.50%		2.50%
Two Point Five Percentage Convertible Notes | Convertible Debt Securities
Effect of Dilutive Share Awards:
Anti-dilutive securities (in shares)		1,889,027		2,488,460
Three Point Zero Percentage Convertible Notes
Effect of Dilutive Share Awards:
Debt instrument, interest rate, stated percentage	3.00%		3.00%
Three Point Zero Percentage Convertible Notes | Convertible Debt Securities
Effect of Dilutive Share Awards:
Anti-dilutive securities (in shares)	1,408,719	2,801,147		2,801,147

Business Acquisitions (Details)

Business Acquisitions (Details) $ in Thousands	Jun. 01, 2018USD ($)	Mar. 01, 2018USD ($)installment	Sep. 30, 2018USD ($)
Business Acquisition [Line Items]
Trade and other receivables			$ 1,264
Other current assets			170
Investments, at Equity, and Advances to 50% or Less Owned Companies			(3,219)
Property and Equipment			4,382
Intangible Assets			950
Notes receivable contributed as equity			(1,904)
Other Assets			7
Accounts payable and other accrued liabilities			(1,609)
Other current liabilities			(269)
Noncontrolling interests in subsidiaries			(82)
Purchase price			(310)
Cash acquired from acquisition			$ 3,600
Cleancor
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired	50.00%		50.00%
Payments to acquire businesses	$ 3,200
Capital contributed	$ 1,900
SCA
Business Acquisition [Line Items]
Payments to acquire businesses		$ 1,300
Number of installments | installment		2
Contingent consideration		$ 800

Equipment Acquisitions and Di_2

Equipment Acquisitions and Dispositions (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)equipment	Sep. 30, 2017USD ($)
Property, Plant and Equipment [Line Items]
Payments to acquire property, plant and equipment | $	$ 43,736	$ 99,306
Sales price of equipment | $	16,000
Gain (loss) on disposition of property plant equipment | $	$ 6,600
U.S.-flag Harbor Tugs
Property, Plant and Equipment [Line Items]
Number of equipment acquired	5
Number of equipment sold	1
Short-sea Container/RORO Vessels
Property, Plant and Equipment [Line Items]
Number of equipment acquired	2
U.S.-flag Petroleum and Chemical Carrier
Property, Plant and Equipment [Line Items]
Number of equipment sold	1
Inland River Dry Cargo Barges
Property, Plant and Equipment [Line Items]
Number of equipment sold	32
Inland River Specialty Barges
Property, Plant and Equipment [Line Items]
Number of equipment sold	2
Gain (Loss) on Asset Dispositions and Impairments, Net
Property, Plant and Equipment [Line Items]
Amortization of deferred gains included in gains on asset dispositions and impairments, net | $	$ 7,000

Investments, At Equity, And A_2

Investments, At Equity, And Advances To 50% Or Less Owned Companies (Narrative) (Details)	Apr. 30, 2018USD ($)	Sep. 30, 2018USD ($)rail_ferry	Sep. 30, 2017USD ($)
Schedule Of Equity Method Investments [Line Items]
Payments to acquire equity method investments		$ 9,836,000	$ 7,636,000
Proceeds from sale of equity method investments		78,015,000	$ 5,000,000
RF Vessel Holdings
Schedule Of Equity Method Investments [Line Items]
Payments to acquire equity method investments		900,000
Golfo de Mexico
Schedule Of Equity Method Investments [Line Items]
Payments to acquire equity method investments		2,100,000
KSM
Schedule Of Equity Method Investments [Line Items]
Payments to acquire equity method investments		1,000,000
SCFCo Holdings
Schedule Of Equity Method Investments [Line Items]
Proceeds from collection of advance to affiliate		2,400,000
Outstanding working capital advances at end of period		30,000,000
SCF Bunge Marine
Schedule Of Equity Method Investments [Line Items]
Payments to acquire equity method investments		500,000
Dividends received from equity method investments		2,900,000
O'Brien's do Brazil
Schedule Of Equity Method Investments [Line Items]
Dividends received from equity method investments		200,000
Hawker Pacific Airservices Limited
Schedule Of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	34.20%
Proceeds from sale of equity method investments	$ 78,000,000
Equity method investment, realized gain (loss) on disposal	$ 53,900,000
VA&E
Schedule Of Equity Method Investments [Line Items]
Dividends received from equity method investments		400,000
Revolving credit facility, receivable, funds committed to related parties		3,500,000
Subordinated loan		7,300,000
Proceeds from collection of long-term loans and related parties		5,400,000
Payments to fund long-term loans to related parties		5,400,000
Other Corporate Equity Method Investments
Schedule Of Equity Method Investments [Line Items]
Proceeds from collection of advance to affiliate		400,000
Outstanding working capital advances at end of period		2,000,000
Dividends received from equity method investments		800,000
Notes Receivable | Subordinated Debt | VA&E
Schedule Of Equity Method Investments [Line Items]
Subordinated loan		$ 3,500,000
Rail Ferries - Foreign-Flag | RF Vessel Holdings
Schedule Of Equity Method Investments [Line Items]
Number of equipment owned | rail_ferry		2
Rail Ferries - Foreign-Flag | Golfo de Mexico
Schedule Of Equity Method Investments [Line Items]
Number of equipment operated | rail_ferry		2
Foreign-flag Harbor Tugs | KSM
Schedule Of Equity Method Investments [Line Items]
Number of equipment operated | rail_ferry		4
Foreign-flag Ocean Liquid Tank Barge | KSM
Schedule Of Equity Method Investments [Line Items]
Number of equipment operated | rail_ferry		1

Long-Term Debt (Details)

Long-Term Debt (Details)	Oct. 31, 2018	May 15, 2018USD ($)	Sep. 30, 2018USD ($)$ / shares	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)shares$ / shares	Sep. 30, 2017USD ($)	Dec. 31, 2017$ / shares
Debt Instrument [Line Items]
Common stock, par value (in dollars per share) | $ / shares			$ 0.01		$ 0.01		$ 0.01
Stock repurchase program, remaining authorized repurchase amount			$ 71,100,000		$ 71,100,000
Gain (loss) on extinguishment of debt			(160,000)	$ 3,000	(5,609,000)	$ (94,000)
Letters of credit outstanding, amount			10,100,000		$ 10,100,000
Interest rate earned on guarantees					0.50%
SEACOR Marine Holdings Inc.
Debt Instrument [Line Items]
Guarantor obligations, maximum exposure, undiscounted			47,000,000		$ 47,000,000
Guaranty fee income			100,000		200,000
SEACOR Marine Holdings Inc.
Debt Instrument [Line Items]
Letters of credit outstanding, amount			$ 700,000		$ 700,000
Three Point Zero Percentage Convertible Notes
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			3.00%		3.00%
Two Point Five Percentage Convertible Notes
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			2.50%		2.50%
ISH Term Loan | ISH
Debt Instrument [Line Items]
Repayments of long-term debt					$ 12,200,000
Senior Notes | Seven Point Three Seven Five Percentage Senior Notes
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			7.375%		7.375%
Debt instrument, repurchased face amount			$ 5,700,000		$ 5,700,000
Repayments of long-term debt					5,900,000
Gain (loss) on extinguishment of debt					(200,000)
Long-term debt			$ 147,400,000		$ 147,400,000
Senior Notes | Seven Point Three Seven Five Percentage Senior Notes | Subsequent Event
Debt Instrument [Line Items]
Debt instrument, redemption price percentage	100.00%
Convertible Debt | Three Point Zero Percentage Convertible Notes
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			3.00%		3.00%
Debt conversion, original debt, amount		$ 117,800,000
Debt instrument, repurchased face amount			$ 300,000		$ 300,000
Repayments of long-term debt					300,000
Gain (loss) on extinguishment of debt			(5,300,000)
Long-term debt			$ 111,900,000		$ 111,900,000
Convertible Debt | Three Point Two Five Percentage Convertible Notes
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			3.25%		3.25%
Debt instrument, face amount		117,800,000
Bond trading price triggering contingent interest, minimum					$ 1,200
Individual bond, face value		$ 1,000
Debt instrument, contingent interest rate		0.45%
Debt instrument, convertible, conversion ratio		0.013192
Debt instrument, convertible, number of equity instruments (in shares) | shares					1,553,780
Payments of debt issuance costs		$ 2,500,000
Long-term debt, net of discount		95,100,000
Debt Issuance costs, gross, carrying amount of liability component		2,000,000
Debt instrument, convertible, carrying amount of equity component		22,700,000
Debt issuance costs, gross, carrying amount of equity component		$ 500,000
Debt instrument, convertible, discounts and issuance costs, amortization period					7 years
Debt instrument, interest rate, effective percentage			7.20%		7.20%
Convertible Debt | Three Point Two Five Percentage Convertible Notes | Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Debt instrument, redemption price percentage					100.00%
Convertible Debt | Three Point Two Five Percentage Convertible Notes | Debt Instrument, Redemption, Period Two
Debt Instrument [Line Items]
Debt instrument, redemption price percentage					100.00%
Convertible Debt | Two Point Five Percentage Convertible Notes
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			2.50%		2.50%
Line of Credit | Revolving Credit Facility | Sea-Vista
Debt Instrument [Line Items]
Repayments of long-term debt					$ 17,000,000
Line of credit facility, remaining borrowing capacity			$ 72,000,000		72,000,000
Line of Credit | Revolving Credit Facility | ISH
Debt Instrument [Line Items]
Gain (loss) on extinguishment of debt					(100,000)
Line of Credit | Term A-1 Loan | Secured Debt | Sea-Vista
Debt Instrument [Line Items]
Repayments of long-term debt					2,500,000
Line of Credit | Term A-2 Loan | Secured Debt | Sea-Vista
Debt Instrument [Line Items]
Repayments of long-term debt					4,200,000
Notes Payable, Other Payables | Other Long-Term Debt
Debt Instrument [Line Items]
Repayments of long-term debt					500,000
Notes Payable, Other Payables | Other ISH Debt
Debt Instrument [Line Items]
Repayments of long-term debt					$ 1,400,000

Income Taxes (Details)

Income Taxes (Details)	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Statutory rate	21.00%
Income subject to tonnage tax	(2.40%)
Noncontrolling interests	(3.70%)
Foreign earnings not subject to U.S. income tax	(17.70%)
Foreign taxes not creditable against U.S. income tax	4.10%
Subpart F income	12.30%
State taxes	0.70%
Other	0.10%
Effective income tax rate reconciliation, percent	14.40%

Derivative Instruments And He_3

Derivative Instruments And Hedging Strategies - Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Derivative [Line Items]
Derivative gains (losses), net	$ 0	$ 19,727
Exchange Option Liability
Derivative [Line Items]
Derivative gains (losses), net	0	19,436
Forward Currency Exchange, Option And Future Contracts
Derivative [Line Items]
Derivative gains (losses), net	$ 0	$ 291

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets And Liabilities Measured At Fair Value On Recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable security gains (losses), net	$ 1,700	$ (7,100)	$ (1,300)	$ (7,200)
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash, cash equivalents, restricted cash and restricted cash equivalents	327,554		327,554
Marketable securities	41,445		41,445
Construction reserve funds	5,908		5,908
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash, cash equivalents, restricted cash and restricted cash equivalents	0		0
Marketable securities	0		0
Construction reserve funds	0		0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash, cash equivalents, restricted cash and restricted cash equivalents	0		0
Marketable securities	0		0
Construction reserve funds	$ 0		$ 0

Fair Value Measurements - Estim

Fair Value Measurements - Estimated Fair Value of Other Financial Assets And Liabilities (Details) $ in Thousands	Sep. 30, 2018USD ($)
Three Point Zero Percentage Convertible Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, interest rate, stated percentage	3.00%
Reported Value Measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable from third parties (included in other receivables and other assets)	$ 2,226
Investments, at cost, in 50% or less owned companies (included in other assets)	4,300
Long-term debt, including current portion	528,394
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable from third parties (included in other receivables and other assets)	0
Long-term debt, including current portion	0
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable from third parties (included in other receivables and other assets)	2,203
Long-term debt, including current portion	561,044
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable from third parties (included in other receivables and other assets)	0
Long-term debt, including current portion	$ 0
Convertible Debt | Three Point Zero Percentage Convertible Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, interest rate, stated percentage	3.00%
Convertible Debt | Three Point Two Five Percentage Convertible Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, interest rate, stated percentage	3.25%

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured on a Non-recurring Basis (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Jun. 01, 2018
Other Corporate Equity Method Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment charge for an other-than-temporary decline in fair value	$ 100	$ 900
Cleancor
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business acquisition, percentage of voting interests acquired	50.00%		50.00%
Cleancor | Equity in Earnings of 50% or Less Owned Companies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity in earnings (losses) of 50% or less owned companies, net of tax	$ 100
Fair Value, Measurements, Nonrecurring | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, at equity, and advances in 50% or less owned companies	0
Fair Value, Measurements, Nonrecurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, at equity, and advances in 50% or less owned companies	3,219
Fair Value, Measurements, Nonrecurring | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, at equity, and advances in 50% or less owned companies	$ 0

Noncontrolling Interests in S_3

Noncontrolling Interests in Subsidiaries (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	$ 140,597		$ 140,597		$ 129,678
Net Income	27,203	$ 21,104	78,768	$ 2,675
Net income (loss) attributable to noncontrolling interest	$ 10,136	$ 3,543	$ 15,934	13,839
Sea-Vista | Ocean Services
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners	49.00%		49.00%
Noncontrolling interests in subsidiaries	$ 139,566		$ 139,566		128,550
Other Inland River Services Noncontrolling Interests | Inland Services
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	$ 841		$ 841		977
Other Inland River Services Noncontrolling Interests | Minimum | Inland Services
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners	3.00%		3.00%
Other Inland River Services Noncontrolling Interests | Maximum | Inland Services
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners	51.80%		51.80%
Other Noncontrolling Interests | Other Segments
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interests in subsidiaries	$ 190		$ 190		$ 151
Other Noncontrolling Interests | Minimum | Other Segments
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners	5.00%		5.00%
Other Noncontrolling Interests | Maximum | Other Segments
Noncontrolling Interests in Subsidiaries [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners	11.80%		11.80%
Sea-Vista | Ocean Services
Noncontrolling Interests in Subsidiaries [Line Items]
Assets, net	$ 284,800		$ 284,800
Net Income			32,600	33,200
Net income (loss) attributable to noncontrolling interest			$ 16,000	$ 16,300

Multi-Employer and Defined Be_2

Multi-Employer and Defined Benefit Pension Plans (Details) $ in Millions	Sep. 30, 2017USD ($)
Withdrawal from Multiemployer Defined Benefit Plan | American Maritime Officers Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Pension and other postretirement benefit plans, withdrawal liability	$ 34.4

Share Based Compensation (Detai

Share Based Compensation (Details) - shares	Jun. 05, 2018	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Director stock awards granted (in shares)		2,250,000
Employee Stock Purchase Plan shares issued (in shares)		45,251,000
Restricted stock awards granted (in shares)		121,850,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Stock options, outstanding as of December 31, 2017 (in shares)		1,546,014,000
Stock options, granted (in shares)		110,660,000
Stock options, exercised (in shares)		(134,212,000)
Stock options, outstanding as of September 30, 2018 (in shares)		1,522,462,000
Shares available for future grants and ESPP purchases as of September 30, 2018 (in shares)		916,254,000
Increase in number of shares available under employee stock purchase plan (in shares)	300,000

Commitments And Contingencies_2

Commitments And Contingencies (Details) $ in Thousands	Apr. 22, 2013claim	Nov. 16, 2012claim	Dec. 15, 2010claim	Sep. 30, 2018USD ($)claimequipment	Oct. 23, 2018USD ($)	Aug. 02, 2016	Feb. 16, 2016
Loss Contingencies [Line Items]
Unrecorded unconditional purchase obligation, due in remainder of fiscal year				$ 2,584
Unrecorded unconditional purchase obligation, due within two years				2,690
Unrecorded unconditional purchase obligation				$ 5,274
Deepwater Horizon Oil Spill Multi District Litigation
Loss Contingencies [Line Items]
Claims filed | claim			1
Pending claims						11	11
Abney et al. v. Plant Performance Services, LLC et al
Loss Contingencies [Line Items]
Number of plaintiffs | claim		668
Abood et al. v. Plant Performance Services, LLC et al
Loss Contingencies [Line Items]
Number of plaintiffs | claim	174
BELO/ORM
Loss Contingencies [Line Items]
Claims filed | claim				101
BELO/NRC
Loss Contingencies [Line Items]
Claims filed | claim				14
Inland River Towboat
Loss Contingencies [Line Items]
Number of equipment committed to purchase | equipment				1
Ocean Services
Loss Contingencies [Line Items]
Unrecorded unconditional purchase obligation, due in remainder of fiscal year				$ 106
Unrecorded unconditional purchase obligation, due within two years				0
Unrecorded unconditional purchase obligation				106
Inland Services
Loss Contingencies [Line Items]
Unrecorded unconditional purchase obligation, due in remainder of fiscal year				2,478
Unrecorded unconditional purchase obligation, due within two years				2,690
Unrecorded unconditional purchase obligation				$ 5,168
Subsequent Event
Loss Contingencies [Line Items]
Unrecorded unconditional purchase obligation					$ 14,700

Segment Information - Operating

Segment Information - Operating Results, Capital Expenditures And Assets By Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Operating Revenues	$ 220,257	$ 176,605	$ 621,912	$ 441,495
Costs and Expenses:
Operating	147,529	125,692	441,474	301,275
Administrative and general	26,083	20,531	76,189	68,949
Depreciation and amortization	18,616	20,501	57,069	54,689
Total costs and expenses	192,228	166,724	574,732	424,913
Gains (Losses) on Asset Dispositions and Impairments, Net	6,018	5,209	13,569	10,918
Operating Income	34,047	15,090	60,749	27,500
Other Income (Expense):
Derivative gains, net	0	0	0	19,727
Foreign currency gains (losses), net	(328)	969	16	898
Other, net	357	64	54,951	68
Equity in Earnings of 50% or Less Owned Companies, Net of Tax	821	488	1,915	2,929
Income (Loss) from Continuing Operations Before Income Tax Expense (Benefit) and Equity in Earnings of 50% or Less Owned Companies	29,744	(3,106)	89,787	10,333
Capital Expenditures			43,736	99,306
Historical cost	1,403,886	1,506,203	1,403,886	1,506,203	$ 1,380,469
Accumulated depreciation	(545,179)	(487,049)	(545,179)	(487,049)	(502,544)
Net property and equipment	858,707	1,019,154	858,707	1,019,154	877,925
Investments, at Equity, and Advances to 50% or Less Owned Companies	149,184	175,387	149,184	175,387	173,441
Inventories	5,139	3,952	5,139	3,952	4,377
Goodwill	32,767	32,773	32,767	32,773	32,761
Intangible Assets	25,724	30,655	25,724	30,655	28,106
Other current and long-term assets, excluding cash and near cash assets	211,439	137,000	211,439	137,000
Total Assets	1,657,867	1,782,965	1,657,867	1,782,965	$ 1,613,336
Ocean Services
Segment Reporting Information [Line Items]
Operating Revenues	109,939	103,780	317,478	243,442
Inland Services
Segment Reporting Information [Line Items]
Operating Revenues	78,845	63,042	208,175	174,040
Witt O'Brien's LLC
Segment Reporting Information [Line Items]
Operating Revenues	30,259	9,667	93,960	23,665
Other Segments
Segment Reporting Information [Line Items]
Operating Revenues	1,214	116	2,299	348
Intersegment Eliminations
Segment Reporting Information [Line Items]
Operating Revenues	(8)	(14)	(47)	(85)
Intersegment Eliminations | Ocean Services
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0	0
Intersegment Eliminations | Inland Services
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0	0
Intersegment Eliminations | Witt O'Brien's LLC
Segment Reporting Information [Line Items]
Operating Revenues	(8)	(14)	(47)	(85)
Intersegment Eliminations | Other Segments
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0	0
Operating Segments | Ocean Services
Segment Reporting Information [Line Items]
Operating Revenues	109,939	103,780	317,478	243,442
Costs and Expenses:
Operating	64,683	65,866	205,060	137,070
Administrative and general	9,170	9,612	30,047	24,728
Depreciation and amortization	11,298	13,516	35,563	32,792
Total costs and expenses	85,151	88,994	270,670	194,590
Gains (Losses) on Asset Dispositions and Impairments, Net	5,505	73	7,391	(342)
Operating Income	30,293	14,859	54,199	48,510
Other Income (Expense):
Derivative gains, net				0
Foreign currency gains (losses), net	(24)	5	(151)	8
Other, net	(96)	59	585	118
Equity in Earnings of 50% or Less Owned Companies, Net of Tax	2,073	1,493	3,655	8,150
Segment Profit (Loss)	32,246	16,416	58,288	56,786
Capital Expenditures			38,786	66,137
Historical cost	929,825	1,028,685	929,825	1,028,685
Accumulated depreciation	(331,625)	(290,400)	(331,625)	(290,400)
Net property and equipment	598,200	738,285	598,200	738,285
Investments, at Equity, and Advances to 50% or Less Owned Companies	62,999	53,388	62,999	53,388
Inventories	2,509	2,032	2,509	2,032
Goodwill	1,852	1,852	1,852	1,852
Intangible Assets	9,297	12,285	9,297	12,285
Other current and long-term assets, excluding cash and near cash assets	54,416	44,845	54,416	44,845
Total Assets	729,273	852,687	729,273	852,687
Operating Segments | Inland Services
Segment Reporting Information [Line Items]
Operating Revenues	78,845	63,042	208,175	174,040
Costs and Expenses:
Operating	65,667	53,822	176,209	148,978
Administrative and general	3,230	3,141	9,758	11,658
Depreciation and amortization	6,197	6,329	18,674	19,404
Total costs and expenses	75,094	63,292	204,641	180,040
Gains (Losses) on Asset Dispositions and Impairments, Net	513	5,136	6,178	11,260
Operating Income	4,264	4,886	9,712	5,260
Other Income (Expense):
Derivative gains, net				0
Foreign currency gains (losses), net	(282)	992	238	730
Other, net	0	0	14	0
Equity in Earnings of 50% or Less Owned Companies, Net of Tax	(1,245)	(1,235)	(3,115)	(4,877)
Segment Profit (Loss)	2,737	4,643	6,849	1,113
Capital Expenditures			4,075	32,901
Historical cost	437,510	446,759	437,510	446,759
Accumulated depreciation	(190,493)	(175,669)	(190,493)	(175,669)
Net property and equipment	247,017	271,090	247,017	271,090
Investments, at Equity, and Advances to 50% or Less Owned Companies	61,304	65,738	61,304	65,738
Inventories	2,258	1,866	2,258	1,866
Goodwill	2,409	2,415	2,409	2,415
Intangible Assets	9,365	10,860	9,365	10,860
Other current and long-term assets, excluding cash and near cash assets	78,461	54,295	78,461	54,295
Total Assets	400,814	406,264	400,814	406,264
Operating Segments | Witt O'Brien's LLC
Segment Reporting Information [Line Items]
Operating Revenues	30,267	9,681	94,007	23,750
Costs and Expenses:
Operating	16,240	6,068	58,945	15,483
Administrative and general	7,389	2,960	17,896	8,641
Depreciation and amortization	492	206	1,284	613
Total costs and expenses	24,121	9,234	78,125	24,737
Gains (Losses) on Asset Dispositions and Impairments, Net	0	0	0	0
Operating Income	6,146	447	15,882	(987)
Other Income (Expense):
Derivative gains, net				0
Foreign currency gains (losses), net	(12)	29	(27)	62
Other, net	0	0	0	0
Equity in Earnings of 50% or Less Owned Companies, Net of Tax	(13)	100	90	237
Segment Profit (Loss)	6,121	576	15,945	(688)
Capital Expenditures			0	60
Historical cost	1,227	1,227	1,227	1,227
Accumulated depreciation	(1,007)	(915)	(1,007)	(915)
Net property and equipment	220	312	220	312
Investments, at Equity, and Advances to 50% or Less Owned Companies	345	782	345	782
Inventories	214	54	214	54
Goodwill	28,506	28,506	28,506	28,506
Intangible Assets	7,062	7,510	7,062	7,510
Other current and long-term assets, excluding cash and near cash assets	63,578	13,802	63,578	13,802
Total Assets	99,925	50,966	99,925	50,966
Operating Segments | Other Segments
Segment Reporting Information [Line Items]
Operating Revenues	1,214	116	2,299	348
Costs and Expenses:
Operating	957	0	1,349	0
Administrative and general	606	180	1,290	559
Depreciation and amortization	202	0	264	0
Total costs and expenses	1,765	180	2,903	559
Gains (Losses) on Asset Dispositions and Impairments, Net	0	0	0	0
Operating Income	(551)	(64)	(604)	(211)
Other Income (Expense):
Derivative gains, net				0
Foreign currency gains (losses), net	0	(12)	1	(12)
Other, net	452	0	54,354	(300)
Equity in Earnings of 50% or Less Owned Companies, Net of Tax	6	130	1,285	(581)
Segment Profit (Loss)	(93)	54	55,036	(1,104)
Capital Expenditures			747	0
Historical cost	5,192	0	5,192	0
Accumulated depreciation	(265)	0	(265)	0
Net property and equipment	4,927	0	4,927	0
Investments, at Equity, and Advances to 50% or Less Owned Companies	24,536	55,479	24,536	55,479
Inventories	158	0	158	0
Goodwill	0	0	0	0
Intangible Assets	0	0	0	0
Other current and long-term assets, excluding cash and near cash assets	2,177	1,807	2,177	1,807
Total Assets	31,798	57,286	31,798	57,286
Corporate And Eliminations
Segment Reporting Information [Line Items]
Operating Revenues			(47)	(85)
Costs and Expenses:
Operating	(18)	(64)	(89)	(256)
Administrative and general	5,688	4,638	17,198	23,363
Depreciation and amortization	427	450	1,284	1,880
Total costs and expenses	6,097	5,024	18,393	24,987
Gains (Losses) on Asset Dispositions and Impairments, Net	0	0	0	0
Operating Income	(6,105)	(5,038)	(18,440)	(25,072)
Other Income (Expense):
Derivative gains, net				19,727
Foreign currency gains (losses), net	(10)	(45)	(45)	110
Other, net	1	5	(2)	250
Equity in Earnings of 50% or Less Owned Companies, Net of Tax	0	0	0	0
Capital Expenditures			128	208
Historical cost	30,132	29,532	30,132	29,532
Accumulated depreciation	(21,789)	(20,065)	(21,789)	(20,065)
Net property and equipment	8,343	9,467	8,343	9,467
Investments, at Equity, and Advances to 50% or Less Owned Companies	0	0	0	0
Inventories	0	0	0	0
Goodwill	0	0	0	0
Intangible Assets	0	0	0	0
Other current and long-term assets, excluding cash and near cash assets	12,807	22,251	12,807	22,251
Segment Reconciling Items
Other Income (Expense):
Other, net	(4,332)	(19,229)	(25,929)	(37,860)
Equity in Earnings of 50% or Less Owned Companies, Net of Tax	(821)	(488)	(1,915)	(2,929)
Cash and near cash assets	$ 374,907	$ 384,044	$ 374,907	$ 384,044

Segment Information - Revenues

Segment Information - Revenues from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Time charter, bareboat charter and rental income			$ 148,097	$ 137,669
Operating Revenues	$ 220,257	$ 176,605	621,912	441,495
Voyage Charters
Revenues from contracts with customers			66,496	15,311
Contracts of Affreightment
Revenues from contracts with customers			168,507	140,085
Harbor & Ocean Towing
Revenues from contracts with customers			53,777	49,184
Unit Freight
Revenues from contracts with customers			43,384	36,763
Terminal Operations
Revenues from contracts with customers			27,291	23,195
Fleeting Operations
Revenues from contracts with customers			13,325	11,654
Time and Material Contracts
Revenues from contracts with customers			84,896	11,887
Retainer Contracts
Revenues from contracts with customers			7,456	7,581
Product Sales
Revenues from contracts with customers			1,618
Other
Revenues from contracts with customers			7,065	8,166
Product
Cost of goods sold			1,200
Ocean Services
Operating Revenues	109,939	103,780	317,478	243,442
Inland Services
Operating Revenues	78,845	63,042	208,175	174,040
Witt O'Brien's LLC
Operating Revenues	30,259	9,667	93,960	23,665
Other Segments
Operating Revenues	1,214	116	2,299	348
Operating Segments | Ocean Services
Time charter, bareboat charter and rental income			142,306	131,770
Operating Revenues	109,939	103,780	317,478	243,442
Operating Segments | Ocean Services | Voyage Charters
Revenues from contracts with customers			66,496	15,311
Operating Segments | Ocean Services | Contracts of Affreightment
Revenues from contracts with customers			9,101	9,315
Operating Segments | Ocean Services | Harbor & Ocean Towing
Revenues from contracts with customers			53,777	49,184
Operating Segments | Ocean Services | Unit Freight
Revenues from contracts with customers			43,384	36,763
Operating Segments | Ocean Services | Terminal Operations
Revenues from contracts with customers			0	0
Operating Segments | Ocean Services | Fleeting Operations
Revenues from contracts with customers			0	0
Operating Segments | Ocean Services | Time and Material Contracts
Revenues from contracts with customers			0	0
Operating Segments | Ocean Services | Retainer Contracts
Revenues from contracts with customers			0	0
Operating Segments | Ocean Services | Product Sales
Revenues from contracts with customers			0
Operating Segments | Ocean Services | Other
Revenues from contracts with customers			2,414	1,099
Operating Segments | Inland Services
Time charter, bareboat charter and rental income			5,535	5,899
Operating Revenues	78,845	63,042	208,175	174,040
Operating Segments | Inland Services | Voyage Charters
Revenues from contracts with customers			0	0
Operating Segments | Inland Services | Contracts of Affreightment
Revenues from contracts with customers			159,406	130,770
Operating Segments | Inland Services | Harbor & Ocean Towing
Revenues from contracts with customers			0	0
Operating Segments | Inland Services | Unit Freight
Revenues from contracts with customers			0	0
Operating Segments | Inland Services | Terminal Operations
Revenues from contracts with customers			27,291	23,195
Operating Segments | Inland Services | Fleeting Operations
Revenues from contracts with customers			13,325	11,654
Operating Segments | Inland Services | Time and Material Contracts
Revenues from contracts with customers			0	0
Operating Segments | Inland Services | Retainer Contracts
Revenues from contracts with customers			0	0
Operating Segments | Inland Services | Product Sales
Revenues from contracts with customers			0
Operating Segments | Inland Services | Other
Revenues from contracts with customers			2,618	2,522
Operating Segments | Witt O'Brien's LLC
Time charter, bareboat charter and rental income			0	0
Operating Revenues	30,267	9,681	94,007	23,750
Operating Segments | Witt O'Brien's LLC | Voyage Charters
Revenues from contracts with customers			0	0
Operating Segments | Witt O'Brien's LLC | Contracts of Affreightment
Revenues from contracts with customers			0	0
Operating Segments | Witt O'Brien's LLC | Harbor & Ocean Towing
Revenues from contracts with customers			0	0
Operating Segments | Witt O'Brien's LLC | Unit Freight
Revenues from contracts with customers			0	0
Operating Segments | Witt O'Brien's LLC | Terminal Operations
Revenues from contracts with customers			0	0
Operating Segments | Witt O'Brien's LLC | Fleeting Operations
Revenues from contracts with customers			0	0
Operating Segments | Witt O'Brien's LLC | Time and Material Contracts
Revenues from contracts with customers			84,896	11,887
Operating Segments | Witt O'Brien's LLC | Retainer Contracts
Revenues from contracts with customers			7,456	7,581
Operating Segments | Witt O'Brien's LLC | Product Sales
Revenues from contracts with customers			0
Operating Segments | Witt O'Brien's LLC | Other
Revenues from contracts with customers			1,655	4,282
Operating Segments | Other Segments
Time charter, bareboat charter and rental income			256	0
Operating Revenues	$ 1,214	$ 116	2,299	348
Operating Segments | Other Segments | Voyage Charters
Revenues from contracts with customers			0	0
Operating Segments | Other Segments | Contracts of Affreightment
Revenues from contracts with customers			0	0
Operating Segments | Other Segments | Harbor & Ocean Towing
Revenues from contracts with customers			0	0
Operating Segments | Other Segments | Unit Freight
Revenues from contracts with customers			0	0
Operating Segments | Other Segments | Terminal Operations
Revenues from contracts with customers			0	0
Operating Segments | Other Segments | Fleeting Operations
Revenues from contracts with customers			0	0
Operating Segments | Other Segments | Time and Material Contracts
Revenues from contracts with customers			0	0
Operating Segments | Other Segments | Retainer Contracts
Revenues from contracts with customers			0	0
Operating Segments | Other Segments | Product Sales
Revenues from contracts with customers			1,618
Operating Segments | Other Segments | Other
Revenues from contracts with customers			425	348
Corporate And Eliminations
Time charter, bareboat charter and rental income			0	0
Operating Revenues			(47)	(85)
Corporate And Eliminations | Voyage Charters
Revenues from contracts with customers			0	0
Corporate And Eliminations | Contracts of Affreightment
Revenues from contracts with customers			0	0
Corporate And Eliminations | Harbor & Ocean Towing
Revenues from contracts with customers			0	0
Corporate And Eliminations | Unit Freight
Revenues from contracts with customers			0	0
Corporate And Eliminations | Terminal Operations
Revenues from contracts with customers			0	0
Corporate And Eliminations | Fleeting Operations
Revenues from contracts with customers			0	0
Corporate And Eliminations | Time and Material Contracts
Revenues from contracts with customers			0	0
Corporate And Eliminations | Retainer Contracts
Revenues from contracts with customers			0	0
Corporate And Eliminations | Product Sales
Revenues from contracts with customers			0
Corporate And Eliminations | Other
Revenues from contracts with customers			$ (47)	$ (85)

Discontinued Operations (Detail

Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Costs and Expenses:
Income (Loss) from Discontinued Operations, Net of Tax	$ 0	$ 10,927	$ 0	$ (23,150)
Discontinued Operations
Costs and Expenses:
Income (Loss) from Discontinued Operations, Net of Tax		10,927		(23,150)
Reportable Legal Entities | Offshore Marine Services | Discontinued Operations, Disposed of by Means Other than Sale, Spinoff
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Operating Revenues		0		62,291
Costs and Expenses:
Operating		0		65,888
Administrative and general		0		29,682
Depreciation and amortization		0		22,181
Total costs and expenses		0		117,751
Gains on Asset Dispositions, Net		0		4,219
Operating Income (Loss)		0		(51,241)
Other Income, Net		0		1,780
Income Tax Expense (Benefit)		0		(12,931)
Equity in Earnings of 50% or Less Owned Companies, Net of Tax		0		1,663
Income (Loss) from Discontinued Operations, Net of Tax		0		(34,867)
Net Loss Attributable to Noncontrolling Interests		0		(1,892)
Reportable Legal Entities | Illinois Corn Processing LLC | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Operating Revenues		0		78,061
Costs and Expenses:
Operating		0		76,306
Administrative and general		0		2,109
Depreciation and amortization		0		2,354
Total costs and expenses		0		80,769
Operating Income (Loss)		0		(2,708)
Other Income, Net		18,223		20,558
Income Tax Expense (Benefit)		7,296		7,363
Income (Loss) from Discontinued Operations, Net of Tax		10,927		10,487
Net Loss Attributable to Noncontrolling Interests		0		(539)
Consolidation, Eliminations | Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Operating Revenues		0		(1,176)
Costs and Expenses:
Operating		0		(1,289)
Administrative and general		0		(42)
Total costs and expenses		0		(1,331)
Operating Income (Loss)		0		155
Other Income, Net		0		1,738
Income Tax Expense (Benefit)		0		663
Income (Loss) from Discontinued Operations, Net of Tax		$ 0		$ 1,230