SEACOR Marine (SMHI) 10-Q 12 Nov 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Oct. 31, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Trading Symbol	SMHI
Entity Registrant Name	SEACOR Marine Holdings Inc.
Entity Central Index Key	0001690334
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		21,855,014
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	1-37966
Entity Tax Identification Number	472564547
Entity Address, Address Line One	12121 Wickchester
Entity Address, Address Line Two	Suite 500
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77079
City Area Code	(346)
Local Phone Number	980-1700

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current Assets:
Cash and cash equivalents	$ 38,155	$ 91,597
Restricted cash	4,016	1,657
Receivables:
Trade, net of allowance for doubtful accounts of $455 and $860 in 2019 and 2018, respectively	58,954	55,048
Other	6,835	11,292
Inventories	1,408	1,977
Prepaid expenses and other	3,146	2,239
Assets held for sale	13,127	15,222
Total current assets	125,641	179,032
Property and Equipment:
Historical cost	1,070,374	1,116,583
Accumulated depreciation	(400,628)	(461,399)
Property and equipment	669,746	655,184
Construction in progress	70,275	88,918
Net property and equipment	740,021	744,102
Right-of-Use Asset - Operating Leases	18,774
Investments, at Equity, and Advances to 50% or Less Owned Companies	118,222	121,773
Construction Reserve Funds	18,161	28,061
Other Assets	3,422	3,690
Assets Held for Sale	16,265	26,280
Total assets	1,040,506	1,102,938
Current Liabilities:
Current portion of operating lease liabilities	15,182
Current portion of long-term debt	23,446	16,812
Accounts payable and accrued expenses	26,507	18,089
Due to SEACOR Holdings	77	452
Accrued wages and benefits	3,289	4,122
Accrued income taxes	3,231	1,918
Deferred revenue	3,303	1,327
Accrued capital, repair and maintenance expenditures	15,992	18,757
Other current liabilities	16,557	19,614
Liabilities associated with assets held for sale	3,813	2,526
Total current liabilities	111,397	83,617
Long-Term Operating Lease Liabilities	12,878
Long-Term Debt	375,772	387,854
Conversion Option Liability on Convertible Senior Notes	4,543	5,276
Deferred Income Taxes	36,921	44,685
Deferred Gains and Other Liabilities	4,848	26,571
Total liabilities	546,359	548,003
SEACOR Marine Holdings Inc. stockholders’ equity:
Common stock, $.01 par value, 60,000,000 shares authorized; 21,868,718 and 20,443,215 shares issued in 2019 and 2018, respectively	219	204
Additional paid-in capital	427,823	415,372
Retained earnings	64,929	126,834
Shares held in treasury of 42,504 and 4,007, respectively, at cost	(614)	(91)
Accumulated other comprehensive loss, net of tax	(21,105)	(16,788)
Total stockholders equity	471,252	525,531
Noncontrolling interests in subsidiaries	22,895	29,404
Total equity	494,147	554,935
Total liabilities and equity	$ 1,040,506	$ 1,102,938

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Trade receivables, allowance for doubtful accounts	$ 455	$ 860
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)	21,868,718	20,443,215
Shares held in treasury (in shares)	42,504	4,007

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Statements of Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Operating Revenues	$ 54,700	$ 58,169	$ 152,422	$ 144,670
Costs and Expenses:
Operating	27,211	38,400	97,747	99,839
Administrative and general	12,509	11,767	36,148	39,182
Lease expense	4,171	3,292	12,636	9,881
Depreciation and amortization	16,091	16,397	48,600	52,940
Costs and expenses	59,982	69,856	195,131	201,842
Gain (loss) on Asset Dispositions and Impairments, Net	861	(1,765)	(2,719)	(3,493)
Operating Loss	(4,421)	(13,452)	(45,428)	(60,665)
Other Income (Expense):
Interest income	317	305	886	869
Interest expense	(7,362)	(7,660)	(22,659)	(20,077)
SEACOR Holdings guarantee fees	(26)	(5)	(87)	(24)
Loss on Debt Extinguishment		(638)		(638)
Derivative (gains) losses, net	3,057	4,387	734	(9,797)
Foreign currency gains, net	(370)	(296)	(624)	(967)
Other, net		678		678
Nonoperating income expense	(4,384)	(3,229)	(21,750)	(29,956)
Loss from Continuing Operations Before Income Tax Benefit and Equity in Earnings of 50% or Less Owned Companies	(8,805)	(16,681)	(67,178)	(90,621)
Income Tax Expense (Benefit)	1,277	1,248	(5,606)	(13,304)
Loss from Continuing Operations Before Equity in Earnings of 50% or Less Owned Companies	(10,082)	(17,929)	(61,572)	(77,317)
Equity in Losses of 50% or Less Owned Companies	(1,325)	(1,022)	(11,879)	(1,734)
Loss from Continuing Operations	(11,407)	(18,951)	(73,451)	(79,051)
(Loss) Income on Discontinued Operations, Net of Tax	(6,834)	3,185	(3,327)	4,968
Net Loss	(18,241)	(15,766)	(76,778)	(74,083)
Net Income (Loss) attributable to Noncontrolling Interests in Subsidiaries	204	191	(4,395)	(4,269)
Net Loss attributable to SEACOR Marine Holdings Inc.	$ (18,445)	$ (15,957)	$ (72,383)	$ (69,814)
Basic and Diluted Income (Loss) Per Common Share and Warrants of SEACOR Marine Holdings Inc.
Continuing operations (Basic)	$ (0.49)	$ (0.85)	$ (2.95)	$ (3.66)
Discontinued operations (Basic)	(0.29)	0.14	(0.14)	0.24
Basic Income (Loss) Per Common Share	(0.78)	(0.71)	(3.09)	(3.42)
Continuing operations (Diluted)	(0.49)	(0.85)	(2.95)	(3.66)
Discontinued operations (Diluted)	(0.29)	0.14	(0.14)	0.24
Diluted Income (Loss) Per Common Share	$ (0.78)	$ (0.71)	$ (3.09)	$ (3.42)
Weighted Average Common Shares and Warrants Outstanding:
Basic and diluted shares	23,740,718	22,512,886	23,406,759	20,391,297

Unaudited Condensed Consolida_2

Unaudited Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Net Loss	$ (18,241)	$ (15,766)	$ (76,778)	$ (74,083)
Other Comprehensive Loss:
Foreign currency translation losses	(1,626)	(533)	(1,902)	(1,406)
Derivative (losses) gains on cash flow hedges	(329)	(32)	(2,263)	36
Other comprehensive income	(1,949)	(824)	(4,490)	(1,458)
Income tax benefit (expense)		(11)	173	(46)
Other comprehensive income, net	(1,949)	(835)	(4,317)	(1,504)
Comprehensive Loss	(20,190)	(16,601)	(81,095)	(75,587)
Comprehensive Income (Loss) attributable to Noncontrolling Interests in Subsidiaries	204	172	(4,395)	(4,321)
Comprehensive Loss attributable to SEACOR Marine Holdings Inc.	(20,394)	(16,773)	(76,700)	(71,266)
Interest Expense [Member]
Other Comprehensive Loss:
Reclassification of derivative gains (losses) on cash flow hedges	158	(305)	357	(305)
Equity Method Investments [Member]
Other Comprehensive Loss:
Reclassification of derivative gains (losses) on cash flow hedges	$ (152)	$ 46	$ (682)	$ 217

Unaudited Condensed Consolida_3

Unaudited Condensed Consolidated Statements of Comprehensive Loss (Parenthetical)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Reclassification of derivative losses on cash flow hedges to equity in earnings	50.00%	50.00%	50.00%	50.00%

Unaudited Condensed Consolida_4

Unaudited Condensed Consolidated Statement of Changes In Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Non-Controlling Interests In Subsidiaries [Member]
Balance at Dec. 31, 2017	$ 523,166	$ 177	$ 303,996		$ 216,511	$ (12,493)	$ 14,975
Balance (in shares) at Dec. 31, 2017		17,675,356
Impact of adoption of new accounting standard at Dec. 31, 2017	(12,069)				(12,069)
Balance at Dec. 31, 2017	511,097	$ 177	303,996		204,442	(12,493)	14,975
Issuance of Common Stock	42,995	$ 22	42,973
Issuance of Common Stock (in shares)		2,271,799
Restricted stock grants	1	$ 1
Restricted stock grants (in shares)		120,600
Issuance of Warrants	62,809		62,809
Amortization of employee share awards	2,602		2,602
Exercise of options	813	$ 1	812
Exercise of options (in shares)		65,000
Exercise of Warrants		$ 3		$ (3)
Exercise of Warrants (in shares)		289,550		108
Restricted stock vesting	(83)			$ (83)
Restricted stock vesting (in shares)		(3,772)		3,664
Director share awards	893		893
Director share awards (in shares)		19,285
Acquisition of consolidated joint venture	(12,037)						(12,037)
Issuance of noncontrolling interests	31,385		375				31,010
Net Loss	(74,083)				(69,814)		(4,269)
Other comprehensive loss	(1,504)					(1,452)	(52)
Balance at Sep. 30, 2018	564,888	$ 204	414,460	$ (86)	134,628	(13,945)	29,627
Balance (in shares) at Sep. 30, 2018		20,437,818		3,772
Balance at Jun. 30, 2018	580,815	$ 204	413,754	$ (54)	150,585	(13,129)	29,455
Balance (in shares) at Jun. 30, 2018		20,439,240		1,422
Amortization of employee share awards	706		706
Exercise of Warrants (in shares)		108		108
Restricted stock vesting	(32)			$ (32)
Restricted stock vesting (in shares)		(1,530)		2,242
Net Loss	(15,766)				(15,957)		191
Other comprehensive loss	(835)					(816)	(19)
Balance at Sep. 30, 2018	564,888	$ 204	414,460	$ (86)	134,628	(13,945)	29,627
Balance (in shares) at Sep. 30, 2018		20,437,818		3,772
Balance at Dec. 31, 2018	$ 554,935	$ 204	415,372	$ (91)	126,834	(16,788)	29,404
Balance (in shares) at Dec. 31, 2018	20,443,215	20,439,208		4,007
Impact of adoption of new accounting standard at Dec. 31, 2018	$ 10,416				10,416
Balance at Dec. 31, 2018	565,351	$ 204	415,372	$ (91)	137,250	(16,788)	29,404
Issuance of Common Stock	6,596	$ 7	6,589
Issuance of Common Stock (in shares)		653,872
Restricted stock grants	2	$ 2
Restricted stock grants (in shares)		211,500
Amortization of employee share awards	3,891		3,891
Exercise of options	$ 1,081	$ 1	1,080
Exercise of options (in shares)	86,494	86,494
Exercise of Warrants	$ 3	$ 4		$ (1)
Exercise of Warrants (in shares)		444,391		49
Restricted stock vesting	$ (524)		(2)	$ (522)
Restricted stock vesting (in shares)	(38,448)	(38,448)		38,448
Director share awards	$ 894	$ 1	893
Director share awards (in shares)		30,197
Cancellation of employee share awards (in shares)		(1,000)
Acquisition of consolidated joint venture	(2,114)						(2,114)
Dissolution of an entity	62				62
Net Loss	(76,778)				(72,383)		(4,395)
Other comprehensive loss	(4,317)					(4,317)
Balance at Sep. 30, 2019	$ 494,147	$ 219	427,823	$ (614)	64,929	(21,105)	22,895
Balance (in shares) at Sep. 30, 2019	21,868,718	21,826,214		42,504
Balance at Jun. 30, 2019	$ 511,240	$ 218	424,549	$ (374)	83,312	(19,156)	22,691
Balance (in shares) at Jun. 30, 2019		21,765,331		25,643
Amortization of employee share awards	2,302		2,302
Exercise of options	973	$ 1	972
Exercise of options (in shares)		77,744
Restricted stock vesting	(240)			$ (240)
Restricted stock vesting (in shares)		(16,861)		16,861
Dissolution of an entity	62				62
Net Loss	(18,241)				(18,445)		204
Other comprehensive loss	(1,949)					(1,949)
Balance at Sep. 30, 2019	$ 494,147	$ 219	$ 427,823	$ (614)	$ 64,929	$ (21,105)	$ 22,895
Balance (in shares) at Sep. 30, 2019	21,868,718	21,826,214		42,504

Unaudited Condensed Consolida_5

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash Flows from Continuing Operating Activities:
Net Loss	$ (73,451)	$ (79,051)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	48,600	52,940
Deferred financing costs amortization	883	1,784
Restricted stock amortization	3,891	2,602
Restricted stock vesting	(522)	(83)
Director share awards	894	893
Debt discount amortization	4,201	4,025
Amortization of deferred gains against charter expense		(6,028)
Bad debt (recovery) expense	(404)	86
Loss from equipment sales, retirements or impairments	2,719	3,493
Gain from other sales		(428)
Derivative losses	(734)	9,797
Cash settlement on derivative transactions, net	(346)	(48)
Currency losses	624	966
Deferred income taxes	(9,840)	(20,980)
Equity losses	11,879	1,734
Dividends received from equity investees	1,273	1,324
Changes in Operating Assets and Liabilities:
Accounts receivables	(2,198)	(29,235)
Other assets	345	708
Accounts payable and accrued liabilities	7,971	(1,397)
Net cash used in operating activities	(4,215)	(56,898)
Cash Flows from Continuing Investing Activities:
Purchases of property and equipment	(49,566)	(37,463)
Proceeds from disposition of property and equipment	19,765	2,729
Net change in construction reserve fund	9,900	9,765
Investments in and advances to 50% or less owned companies	(11,355)	(30,253)
Sale of subsidiary joint venture		8,017
Capital distributions from equity investees	413	6,463
Payments received on third party notes receivable, net		99
Principal payments on notes due from equity investees	22
Net cash used in investing activities	(30,821)	(40,643)
Cash Flows from Continuing Financing Activities:
Payments on long-term debt	(20,075)	(38,053)
Proceeds from issuance of long-term debt, net of issue costs		62,353
Purchase of subsidiary shares from noncontrolling interests	(3,392)
Proceeds from exercise of stock options and Warrants	1,084	813
Issuance of stock		42,996
Issuance of Warrants		12,809
Net cash (used in) provided by financing activities	(22,383)	80,918
Effects of Exchange Rate Changes on Cash and Cash Equivalents	1,596	(5,005)
Net Decrease in Cash, Restricted Cash and Cash Equivalents	(55,823)	(21,628)
Cash Flows from Discontinued Operations:
Operating Activities	5,091	6,777
Investing Activities	(1,107)	2,355
Effects of Exchange Rate Changes on Cash, Restricted Cash and Cash Equivalents	(624)	4,464
Net Decrease in Cash, Restricted Cash and Cash Equivalents on Discontinued Operations	3,360	13,596
Net Decrease in Cash, Restricted Cash and Cash Equivalents	(52,463)	(8,032)
Cash, Restricted Cash and Cash Equivalents, Beginning of Period	96,852	112,551
Cash, Restricted Cash and Cash Equivalents, End of Period	$ 44,389	$ 104,519

Basis of Presentation and Accou

Basis of Presentation and Accounting Policies	9 Months Ended
	Sep. 30, 2019
Basis Of Presentation And Accounting Policies [Abstract]
Basis of Presentation and Accounting Policies	1. The condensed consolidated financial statements include the accounts of SEACOR Marine Holdings Inc. and its consolidated subsidiaries (the “Company”). In the opinion of management, all adjustments (consisting of normal recurring adjustments) have been made to fairly present the unaudited condensed consolidated financial statements for the periods indicated. 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 Company’s financial statements and related notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2018. Unless the context otherwise indicates, any reference in this Quarterly Report on Form 10-Q to the “Company” refers to SEACOR Marine Holdings Inc. and its consolidated subsidiaries and any reference in this Quarterly Report on Form 10-Q to “SEACOR Marine” refers to SEACOR Marine Holdings Inc. without its consolidated subsidiaries. Recently Adopted Accounting Standards. On February 25, 2016, the Financial Accounting Standards Board (“FASB”) issued a comprehensive new leasing standard, ASC 842, 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. It also requires additional disclosures about leasing arrangements. The Company adopted the new standard on January 1, 2019 and applied the transition provisions of the new standard with recognition of a cumulative-effect adjustment to the opening balance of retained earnings and therefore the Company was not required to recast previously issued financial statements. The Company elected the available practical expedients permitted under the guidance including the ability to carry forward the existing lease classification, the option to not separate lease and non-lease components in calculating the right-of-use assets and corresponding lease liabilities and to not apply the recognition requirements of Topic 842 to short-term leases (leases that have a duration of twelve months or less at lease inception). For some leases, it was not possible for the Company to determine the interest rate implicit in each of its operating leases and therefore used the Company’s incremental borrowing rate in calculating operating lease right-of-use assets and lease liabilities. The Company included renewal options that were reasonably certain of being exercised in determining the lease term. Upon adoption, the Company recorded $33.7 million of right-of-use assets, $31.9 million in lease liabilities, and a cumulative-effect adjustment to the opening balance of retained earnings of $1.7 million for certain of the Company’s equipment, office and land leases. In addition, unamortized deferred gains for four vessels previously accounted for under sale-leaseback arrangements of $8.7 million, ($11.0 million deferred gains net of $2.3 million deferred taxes), were fully recognized as an adjustment to the opening balance of retained earnings. In February 2018, the FASB issued ASU 2018-02, “Income Statement—Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income” (“ASU 2018-02”). The amendments in ASU 2018-02 permit a reclassification from Accumulated Other Comprehensive Income (“AOCI”) to retained earnings for stranded tax effects resulting from the Tax Cuts & Jobs Act (“TCJA”). Consequently, the amendments eliminate the stranded tax effects resulting from the Tax Act and will improve the usefulness of information reported to financial statement users. ASU 2018-02 is effective for the Company for annual and interim reporting periods beginning after December 15, 2018. For the period ending September 30, 2019, an election has not been made to reclassify the income tax effects of the TCJA from AOCI to retained earnings. In June 2018, the FASB issued ASU 2018-07, a new accounting standard which addresses aspects of the accounting for nonemployee share-based payment transactions. The standard is effective for interim and annual periods beginning after December 15, 2018. The adoption of the new standard by the Company did not have a material impact on its consolidated financial position or its results of operations and cash flows. Critical Accounting Policies. Assets Held for Sale. On November 1, 2019, SEACOR Capital (UK) Limited (“SEACAP”), a wholly owned subsidiary of SEACOR Marine, entered into a sale and purchase agreement (“SPA”) to sell the Company’s North Sea emergency response and rescue vessel (“ERRV”) business to North Star Holdco Limited (“North Star”) through the sale of 100% of the equity of its subsidiary, Boston Putford Offshore Safety Limited (“BPOS” and together with its subsidiaries, the “BPOS Group”), upon the terms and subject to the conditions set forth in the SPA (“the Sale”). As consideration for the Sale, at the closing of the transaction, North Star will pay SEACAP an aggregate purchase price equal to approximately £19.5 million (equivalent to approximately US$25.1 million based on the USD to GDP closing exchange rate on October 31, 2019) subject to adjustment for continued intercompany services provided and interest calculated from July 31, 2019. Additional consideration of up to £4.0 million (equivalent to approximately US$5.2 million based on the same exchange rate) may be payable to SEACAP based on revenue targets being achieved in 2020 and 2021. For all periods presented herein, the Company has reported the historical position, results of operations and cash flows of BPOS as Assets Held for Sale (see Note 16). 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 over control of the promised goods or services to its customers. Costs to obtain or fulfill a contract are expensed as incurred. Lease Revenues. The Company’s lease revenues are primarily from time charters and bareboat charters that are recognized ratably over the lease term as services are provided, typically on a per day basis. The charterer will take the vessel on hire for a specific period of time, use the vessel to move cargo, people or equipment and will pay the Company the agreed upon rate per day. Under a time charter the Company provides a vessel to a customer for a set term and the Company 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, including fuel, and the risk of operation (see Note 15). Revenues from Customers of Management Services. The Company contracts with various customers to carry out management services for vessels as agents for and on behalf of ship owners. These services include crew management, technical management, commercial management, insurance arrangements, sale and purchase of vessel, provisions and bunkering. As manager, the Company undertakes to use its best endeavors to provide the agreed management services as agents for, and on behalf of the ship owners in accordance with sound ship management practice and to protect and promote the interest of the owners in all matters relating to the provision of the agreed upon management services. The Company also contracts with various customers to carry out management services regarding engineering for vessel construction and vessel conversions. The majority of the ship management agreements have a duration of one to three years and are typically billed monthly. The Company 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 (see Note 15). Revenue that does not meet the aforementioned criteria is deferred until the criteria is met and are considered contract liabilities. Contract liabilities which are included in other current liabilities in the accompanying condensed consolidated balance sheets, for the nine months ended September 30 were as follows (in thousands): 2019 2018 Balance at beginning of period $ 1,327 $ 10,104 Revenues deferred during the period 5,022 2,756 Revenues recognized during the period (3,046 ) (3,191 ) Balance at end of period $ 3,303 $ 9,669 As of September 30, 2019, contract liabilities include $1.9 million related to the time charter of an offshore support vessel to a customer for which collection was not reasonably assured. The Company will recognize revenues when collected or when collection is reasonably assured. All costs and expenses related to this charter were recognized as incurred. As of September 30, 2019, the Company has deferred $1.2 million received as reimbursement for upgrades of a vessel and deferred reservation fees. The amount will be recognized as revenues over time, commencing with the start of the new time charter agreement for the vessel. The remaining balance of $0.2 million as of September 30, 2019 is comprised of contract liabilities to two customers for which collection is not reasonably assured. Property and Equipment. Equipment, stated at cost, is depreciated using the straight-line method over the estimated useful life of the asset to an estimated salvage value. With respect to each class of asset, the estimated useful life is based upon a newly built asset being placed into service and represents the time period beyond which it is typically not justifiable for the Company to continue to operate the asset in the same or similar manner. From time to time, the Company may acquire older assets that have already exceeded the Company’s useful life policy, in which case the Company depreciates such assets based on its best estimate of remaining useful life, typically the next survey or certification date. As of September 30, 2019, the estimated useful life (in years) of each of the Company’s major categories of new equipment was as follows: Offshore Support Vessels: Crew transfer vessels 10 All other offshore support vessels (excluding crew transfer vessels) 20 Equipment maintenance and repair costs and the costs of routine overhauls, drydockings and inspections performed on vessels and equipment are charged to operating expense as incurred. Expenditures that extend the useful life or improve the marketing and commercial characteristics of equipment as well as major renewals and improvements to other properties are capitalized. Certain interest costs incurred during the construction of equipment are capitalized as part of the assets’ carrying values and are amortized over such assets’ estimated useful lives. During the nine months ended September 30, 2019, capitalized interest totaled $1.2 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 values and impairment charges are recorded if the carrying value exceeds fair value. The Company performs its testing on an asset or asset group basis. Generally, fair value is determined using valuation techniques, such as expected undiscounted cash flows or appraisals, as appropriate. During the nine months ended September 30, 2019, the Company recognized $11.7 million of impairment charges primarily related to two anchor-handling towing supply (“AHTS”) vessels previously removed from service and adjusted to scrap value, two AHTS vessels and four fast support vessels (“FSV”) each of which has been adjusted to indicative sales price, and two leased-in vessels (one AHTS and one platform supply vessel (“PSV”)), adjusted for indicative future cash flows. During the nine months ended September 30, 2018, the Company recognized $3.0 million of impairment charges primarily related to four AHTS vessels removed from service and adjusted to scrap value. Impairment of 50% 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, 2019, the Company did not recognize any impairment charges related to its 50% or less owned companies. During the nine months ended September 30, 2018, the Company recognized impairment charges of $1.2 million related to one of its 50% or less owned companies which the Company believed was unable to meet all of its’ liabilities. Income Taxes. During the nine months ended September 30, 2019, the Company's effective income tax rate of 8.3% was primarily due to taxes provided on income attributable to noncontrolling interests, foreign sourced income not subject to U.S. income taxes, foreign taxes not creditable against U.S. income taxes, and the annual return-to-accrual adjustment for the prior year. 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. In 2018, 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 and were amortized in operating expenses as a reduction to rental expense. The new lease accounting pronouncement which was adopted on January 1, 2019 required the recognition of unamortized gains as a cumulative-effect adjustment to the opening balance of retained earnings. Deferred gain activity related to these transactions for the nine months ended September 30 was as follows (in thousands): 2019 2018 Balance at beginning of period $ 11,819 $ 25,006 Amortization of deferred gains included in operating expenses as a reduction to rental expense — (6,053 ) Impact of adoption of new accounting standard (11,026 ) — Other adjustments (390 ) (416 ) Balance at end of period $ 403 $ 18,537 Accumulated Other Comprehensive Income (Loss). The components of accumulated other comprehensive loss were as follows (in thousands): SEACOR Marine Holdings Inc. Stockholders’ Equity Noncontrolling Interests Foreign Currency Translation Adjustments Derivative Losses on Cash Flow Hedges, net Total Foreign Currency Translation Adjustments Derivative Income (Losses) on Cash Flow Hedges, net Other Comprehensive Loss December 31, 2018 $ (15,472 ) $ (1,316 ) $ (16,788 ) $ (1,445 ) $ (11 ) — Other comprehensive loss (1,902 ) (2,415 ) (4,317 ) — — $ (4,317 ) Nine Months Ended September 30, 2019 $ (17,374 ) $ (3,731 ) $ (21,105 ) $ (1,445 ) $ (11 ) $ (4,317 ) Leases. The Company determines if an arrangement contains a lease at the inception of a contract. Leases with contractual terms less than twelve months are not recorded on the balance sheet and lease expense is recognized on a straight-line basis over the term of the short-term lease. Leases with contractual terms longer than twelve months are categorized as either operating or finance, with corresponding right-of-use asset and lease liability recorded on the balance sheet. Finance leases are generally those leases that substantially utilize or pay for the entire asset over its estimated life. All other leases are categorized as operating leases. Right-of-use assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Lease liabilities are recognized at the present value of the fixed lease payments, using an implicit discount rate if available, or if not readily available, the Company’s incremental borrowing rate. Right-of-use assets are recognized based on the initial present value of the fixed lease payments and are tested for impairment in the same manner as long-lived assets used in operations. When options exist to extend the lease term, terminate the lease before the contractual expiration date, or purchase the leased asset, and it is reasonably certain that these options will be exercised, the options are considered in determining the classification and measurement of the lease. Loss Per Share. Basic loss per common share of the Company is computed based on the weighted average number of common shares and warrants to purchase common shares at an exercise price of $0.01 per share (“Warrants”) issued and outstanding during the relevant periods. The Warrants are included in the basic loss per common share because the shares issuable upon exercise of the Warrants are issuable for de minimis cash consideration and therefore not anti-dilutive. Diluted loss per common share of the Company is computed based on the weighted average number of common shares and Warrants issued and outstanding plus the effect of other potentially dilutive securities through the application of the treasury stock method and the if-converted method that assumes all common shares have been issued and outstanding during the relevant periods pursuant to the conversion of the Convertible Senior Notes. For the nine months ended September 30, 2019 and 2018, diluted earnings per common share of the Company excluded 2,183,708 common shares, respectively, issuable pursuant to the Company’s Convertible Senior Notes (see Note 5) as the effect of their inclusion in the computation would be anti-dilutive. In addition, for the nine months ended September 30, 2019 and 2018, diluted loss per common share of the Company excluded 282,050 and 196,338 shares of restricted stock, respectively, and 397,119 and 732,191 shares of stock, respectively, issuable upon exercise of outstanding stock options as the effect of their inclusion in the computation would be anti-dilutive. New Accounting Pronouncements. In August 2018, the FASB issued ASU 2018-13, a new accounting standard which modifies the disclosure requirements related to fair value measurement. The new guidance is effective for fiscal years beginning after December 15, 2019. The effects of this standard on our financial position or reporting is not expected to be material. In August 2018, the FASB issued ASU 2018-15, a new accounting standard which provided guidance regarding the accounting for fees paid by a customer in a cloud computing arrangement (hosting arrangement). The guidance reduces complexity for the accounting for costs of implementing a cloud computing service arrangement and aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The standard is effective for interim and annual periods beginning after December 15, 2019. The Company is evaluating the provisions of the standard but does not expect the adoption of the new standard to have a material impact on its consolidated financial position or its results of operations and cash flows. In June 2016, the FASB issued ASU 2016-13, an amendment to the accounting standards which replaces the current incurred loss impairment methodology for financial assets measured at amortized cost with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information, including forecasted information, to develop credit loss estimates. The new standard is effective for interim periods beginning after December 15, 2019. Early adoption is permitted for annual periods beginning after December 15, 2018. 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. Reclassification . Certain amounts in the prior year’s condensed consolidated financial statements have been reclassified to conform to the current year presentation. The reclassification had no impact on total assets, liabilities, or net loss.

Transformation, Facility Restru

Transformation, Facility Restructuring and Severance Charges	9 Months Ended
	Sep. 30, 2019
Restructuring And Related Activities [Abstract]
Transformation, Facility Restructuring and Severance Charges	2. Due to the highly competitive nature of the Company’s business and the continuing losses incurred over the last few years, the Company continues to reduce its overall cost structure and workforce to better align the Company with current activity levels. The ongoing transformation plan, which began in the third quarter of 2019 and is expected to extend through the second quarter of 2020 (the “Transformation Plan”), includes a workforce reduction, organization restructuring, facility consolidations and other cost reduction measures and efficiency initiatives across the Company’s geographic regions. The Transformation Plan was initiated to reduce the Company’s overall cost structure and workforce to better align with current activity levels of oil and gas exploration and production. In connection with the Transformation Plan, the Company recognized restructuring and transformation charges of $3.3 million for the three and nine months ended September 30, 2019, which include severance charges of $3.1 million and other restructuring charges of $0.2 million. Other restructuring charges included contract termination costs, relocation and other associated costs. The components of restructuring charges by segment for the three and nine months ended September 30, 2019 were as follows (in thousands): United States (primarily Gulf of Mexico) Africa (primarily West Africa) Middle East and Asia Latin America Europe (primarily North Sea) Total Transformation Plan Severance Charges $ 2,937 $ — $ — $ — $ 119 $ 3,056 Other Charges 247 — — 1 — 248 Total Charges $ 3,184 $ — $ — $ 1 $ 119 $ 3,304 The severance and other restructuring charges gave rise to certain liabilities, the components of which are summarized in the following table (in thousands), and largely relate to liabilities accrued as part of the 2019 Transformation Plan that will be paid pursuant to the respective arrangements and statutory requirements. United States (primarily Gulf of Mexico) Africa (primarily West Africa) Middle East and Asia Latin America Europe (primarily North Sea) Total Transformation Plan Severance Liability $ 526 $ — $ — $ — $ 38 $ 564 Other Liability — — — — — — Total Liability $ 526 $ — $ — $ — $ 38 $ 564 The following table is a summary of the cumulative restructuring and reorganization cost incurred to date in operating charges and the estimated remaining restructuring and reorganization costs to be incurred as of September 30, 2019 (in thousands). Transformation Plan Cumulative restructuring costs incurred to date in operating charges $ 3,304 Estimated additional restructuring costs to be incurred 2,428 Total restructuring and reorganization costs incurred and to be incurred $ 5,732

Equipment Acquisitions and Disp

Equipment Acquisitions and Dispositions	9 Months Ended
	Sep. 30, 2019
Property Plant And Equipment [Abstract]
Equipment Acquisitions and Dispositions	3 . During the nine months ended September 30, 2019, capital acquisitions were $49.6 million. Equipment deliveries during the nine months ended September 30, 2019 include two FSVs, one crew transfer vessel (“CTV”), and two PSVs. During the nine months ended September 30, 2019, the Company sold five AHTS vessels and one specialty vessel previously retired and removed from service, three FSVs, two supply vessels, three liftboats, one CTV and other equipment for $19.9 million cash and one vessel under construction for $4.3 million (all of which was a previously received deposit) and gains of $8.9 million.

Investments, at Equity, and Adv

Investments, at Equity, and Advances to 50% or Less Owned Companies	9 Months Ended
	Sep. 30, 2019
Schedule Of Investments [Abstract]
Investments, at Equity, and Advances to 50% or Less Owned Companies	4 . SEACOSCO . The Company, through SEACOR Offshore Asia LLC, an indirectly wholly owned subsidiary of SEACOR Marine (“SEACOR Offshore Asia”), owns an unconsolidated 50% interest in SEACOSCO Offshore LLC (“SEACOSCO”). China Shipping Fan Tai Limited (“CSFT”) and China Shipping Industry (Hong Kong) Co., Limited (“CSIHK”) own the other 50% interest in SEACOSCO. During the nine months ended September 30, 2019, SEACOSCO took delivery of four PSVs and title to one PSV, and the Company contributed $2.0 million in capital to SEACOSCO for the payment of construction costs. In the year ended December 31, 2018, SEACOSCO took delivery of two PSVs and title to another five of the PSVs, and the Company contributed $29.6 million in capital to SEACOSCO. Effective May 31, 2019, SEACOR Offshore Asia, CSFT, CSIHK and COSCO Shipping Heavy Industry (Guangdong) Co., Ltd. (the “Shipyard”), the shipbuilder and lender under deferred payment agreements (“DPAs”) that are secured by the PSVs acquired by SEACOSCO, entered into a Memorandum of Understanding (“MOU”) pursuant to which (i) the Shipyard agreed to not take any action with respect to any existing defaults under the DPAs until August 31, 2019, (ii) SEACOR Offshore Asia was authorized to provide, in its sole discretion, shareholder loans to SEACOSCO and/or its subsidiaries, in an aggregate amount of $13.0 million, in respect of working capital or other payment obligations at an interest rate of 15% per annum and, subject to the priority of the indebtedness under the DPAs, the shareholder loans will have senior priority to any and all other debts of SEACOSCO and/or its subsidiaries, (“SEACOR Shareholder Loans”), (iii) the parties set out the non-binding principal terms and conditions for SEACOR Offshore Asia’s potential acquisition of the 50% interest in SEACOSCO owned by CSFT and CSIHK and (iv) in connection with such acquisition, SEACOR Offshore Asia or its nominee may acquire from the Shipyard two additional PSVs that had been under options held by SEACOSCO. As of September 30, 2019, the balance on the SEACOR Shareholder Loans is $8.7 million, which is the aggregate amount of Shareholder Loans provided, and SEACOR Marine recognized interest income of $0.1 million. As of September 30, 2019, SEACOSCO is in compliance with all debt covenants and is current in all payments. Management remains in discussions with the Shipyard, CSFT and CSIHK with respect to the other transactions contemplated by the MOU. MEXMAR Offshore International . On December 19, 2018, the Company acquired a 49% interest in MEXMAR Offshore International LLC (“MEXMAR Offshore International”) for consideration of $4.9 million. The joint venture owns 14 vessels servicing the energy industry in Brazil. For the nine months ended September 30, 2019, the joint venture has incurred losses in excess of the initial investment, and the equity investment on the Company’s books has been reduced to zero. The Company has not provided any guarantees or capital commitments with respect to this investment. FRS Windcat Offshore Logistics GmbH . During the nine months ended September 30, 2019, the Company concluded the sale of one vessel under construction for $4.3 million to a wholly owned subsidiary of FRS Windcat Offshore Logistics GmbH, an unconsolidated joint venture. Guarantees. One of the Company's 50% or less owned companies have bank debt secured by, among other things, a first preferred mortgage on the 50% or less owned companies’ vessels. The banks also have the authority to require the Company and its partners to fund uncalled capital commitments, as defined in the partnership agreements governing the companies. In such event, the Company would be required to contribute its allocable share of uncalled capital, which was $0.4 million in the aggregate as of September 30, 2019. This liability is included with the other long-term liabilities.

Long Term Debt

Long Term Debt	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Long Term Debt	5 . The Company’s long-term debt obligations as of September 30, 2019 and December 31, 2018 were as follows (in thousands): September 30, 2019 December 31, 2018 Convertible Senior Notes $ 125,000 $ 125,000 SEACOR Marine Foreign Holdings Syndicated Credit Facility 117,000 126,750 Falcon Global USA Term Loan Facility 102,349 109,099 Sea-Cat Crewzer III Term Loan Facility 24,128 25,989 Windcat Workboats Facilities 23,751 24,850 Falcon Global USA Revolver 15,000 15,000 SEACOR 88/888 Term Loan 11,000 11,000 SEACOR Alps 10,626 — BNDES Equipment Construction Finance Notes 3,820 5,284 $ 432,674 $ 442,972 Portion due within one year (23,446 ) (16,812 ) Debt discount (27,805 ) (32,005 ) Issue costs (5,651 ) (6,301 ) $ 375,772 $ 387,854 As of September 30, 2019, the Company is in compliance with all debt covenants and lender requirements. On August 6, 2019, SEACOR Marine, SEACOR Marine Foreign Holdings Inc., an indirectly wholly owned subsidiary of SEACOR Marine (“SMFH”), and certain vessel-owning subsidiaries of SEACOR Marine, entered into an amendment (the “Amendment”) to the $130.0 million loan facility, dated as of September 26, 2018, with a syndicate of lenders administered by DNB Bank ASA, New York Branch (the “Credit Facility” ) and the related guaranty by SEACOR Marine with respect to the obligations of SMFH under the Credit Facility (the “Guaranty”). The Amendment provides for, among other things, (i) the release of one vessel from a mortgage securing the Credit Facility and the substitution of mortgages over two other vessels owned by vessel-owning subsidiaries of SEACOR Marine, and (ii) the modification of certain financial maintenance and restrictive covenants contained in the Credit Facility or the Guaranty, including with respect to asset maintenance, vessel collateral releases, EBTIDA coverage ratios and the payment of dividends and distributions. On September 30, 2019, the Company took possession of the SEACOR Alps, a Rolls Royce UT771CDL designed diesel electric powered PSV of 3,800 tons deadweight capacity with dynamic position class 2 and firefighting class 1 notations. As part of this transaction, the shipbuilder financed 70% of the total purchase price. This loan bears interest at 5% and is due and payable in 2023. Letters of Credit . As of September 30, 2019, the Company had outstanding letters of credit of $3.8 million securing one long-term debt obligation, $0.3 million securing one lease obligation and $0.2 million for labor and performance guarantees.

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases	6 . LEASES As of September 30, 2019, the Company leases in four AHTS vessels, two liftboats, one FSV, one supply vessel and certain facilities and other equipment. The leases typically contain purchase and renewal options or rights of first refusal with respect to the sale or lease of the equipment. As of September 30, 2019, the remaining lease terms of the vessels have remaining durations from two to 26 months. The lease terms of the other equipment range in duration from four to 327 months. As of September 30, 2019, future minimum payments for operating leases for the remainder of 2019 and the years ended December 31 were as follows (in thousands): Remainder of 2019 $ 4,897 2020 14,066 2021 7,120 2022 663 2023 622 Years subsequent to 2023 4,851 32,219 Interest component (4,159 ) 28,060 Current portion of long-term operating lease liabilities 15,182 Long-term operating lease liabilities $ 12,878 For the nine months ended September 30, 2019, the components of lease expense were as follows (in thousands): Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Operating lease expense $ 3,446 $ 10,669 Short-term lease expense (lease duration of twelve months or less at lease commencement) 725 1,967 $ 4,171 $ 12,636 For the nine months ended September 30, 2019, other information related to operating leases were as follows (in thousands except weighted average data): 2019 Operating cash flows from operating leases $ 14,671 Right-of-use assets obtained for operating lease liabilities $ 33,979 Weighted average remaining lease term, in years 4.9 Weighted average discount rate 4.2 %

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	7 . 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, 2019: Statutory rate 21.0 % Foreign taxes not creditable against U.S. income tax (5.4 ) Foreign earnings not subject to U.S. income tax (3.6 ) Return to provision (3.6 ) Noncontrolling interests (1.9 ) State taxes 1.6 Other 0.2 8.3 %

Derivative Instruments and Hedg

Derivative Instruments and Hedging Strategies	9 Months Ended
	Sep. 30, 2019
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Strategies	8 . Derivative instruments are classified as either assets or liabilities based on their individual fair values. The fair values of the Company’s derivative instruments were as follows (in thousands): September 30, 2019 December 31, 2018 Derivative Asset Derivative Liability Derivative Asset Derivative Liability Derivatives designated as hedging instruments: Interest rate swap agreements (cash flow hedges) $ — $ 3,576 (1) $ — $ 1,659 (1) — 3,576 — 1,659 Derivatives not designated as hedging instruments: Conversion option liability on Convertible Senior Notes — 4,543 — 5,276 $ — $ 8,119 $ — $ 6,935 ( 1 ) Included in other current liabilities in the accompanying condensed consolidated balance sheets. Cash Flow Hedges. The Company and certain of its 50% or less owned companies have interest rate swap agreements designated as cash flow hedges. By entering into these interest rate swap agreements, the Company and its 50% or less owned companies have converted the variable LIBOR or EURIBOR component of certain of their outstanding borrowings to a fixed interest rate. The Company recognized immaterial losses on derivative instruments designated as cash flow hedges during the nine months ended September 30, 2019. As of September 30, 2019, the interest rate swaps held by the Company and its 50% or less owned companies were as follows: • Windcat Workboats Holdings Ltd., an indirectly wholly owned subsidiary of SEACOR Marine (“Windcat Workboats”) has two interest rate swap agreements maturing in 2021 that call for the Company to pay a fixed rate of interest of (0.03%) per annum on the aggregate notional value of €15.0 million (approximately $16.4 million) and receive a variable interest rate based on EURIBOR on the aggregate notional value; • SMFH has an interest rate swap agreement maturing in 2023 that calls for SMFH to pay a fixed rate of interest of 3.32% per annum on the amortized notional value of $9.0 million and receive a variable interest rate based on LIBOR on the amortized notional value; • SMFH has an interest rate swap agreement maturing in 2023 that calls for SMFH to pay a fixed rate of interest of 3.195% per annum on the amortized notional value of $50.0 million and receive a variable interest rate based on LIBOR on the amortized notional value; • SEACOR 88 LLC and SEACOR 888 LLC, both indirectly wholly owned subsidiaries of SEACOR Marine (collectively, “SEACOR 88/888”) have an interest rate swap agreement maturing in 2023 that calls for SEACOR 88/888 to pay a fixed rate of interest of 3.2% per annum on the amortized notional value of $5.5 million and receive a variable interest rate based on LIBOR on the amortized notional value; and • Mantenimiento Express Maritimo, S.A.P.I. de (“ Other Derivative Instruments. The Company recognized (losses) gains on derivative instruments not designated as hedging instruments for the nine months ended September 30 as follows (in thousands): 2019 2018 Conversion option liability on Convertible Senior Notes $ 734 $ (11,096 ) Interest rate swap agreements — 1,299 $ 734 $ (9,797 ) The conversion option liability relates to the bifurcated embedded conversion option in the Convertible Senior Notes issued to investment funds managed and controlled by The Carlyle Group (“Carlyle”). See Note 9, Fair Value Measurements. The Company and certain of its 50% or less owned companies have entered into interest rate swap agreements that did not qualify as cash flow hedges for the general purpose of providing protection against increases in interest rates, which might lead to higher interest costs. As of September 30, 2019, these interest rate swaps held by the Company or its 50% or less owned companies were as follows: • SEACOR OSV Partners I LP (“OSV Partners”) has two interest rate swap agreements with maturities in 2020 that call for OSV Partners to pay a fixed rate of interest ranging from 1.89% to 2.27% per annum on the aggregate amortized notional value of $24.1 million and receive a variable interest rate based on LIBOR on the aggregate amortized notional value.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	9 . 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 Level Level Level The Company’s financial assets and liabilities as of September 30, 2019 that are measured at fair value on a recurring basis were as follows (in thousands): Level 1 Level 2 Level 3 September 30, 2019 ASSETS Construction reserve funds $ 18,161 $ — $ — LIABILITIES Derivative instruments — 3,576 — Conversion Option Liability on Convertible Senior Notes — — 4,543 December 31, 2018 ASSETS Construction reserve funds $ 28,221 $ — $ — LIABILITIES Derivative instruments — 1,659 — Conversion Option Liability on Convertible Senior Notes — — 5,276 Level 3 . The fair value of the conversion option liability on the Convertible Senior Notes is estimated with significant inputs that are both observable and unobservable in the market and therefore is considered a Level 3 fair value measurement. The Company used a binomial lattice model that assumes the holders will maximize their value by finding the optimal decision between redeeming at the redemption price or converting into shares of Common Stock. This model estimates the fair value of the conversion option as the differential in the fair value of the notes including the conversion option compared with the fair value of the notes excluding the conversion option. The significant observable inputs used in the fair value measurement include the price of Common Stock and the risk-free interest rate. The significant unobservable inputs are the estimated Company credit spread and Common Stock volatility, which were based on comparable companies in the transportation and energy industries. The estimated fair values of the Company’s other financial assets and liabilities as of September 30, 2019 were as follows (in thousands): Estimated Fair Value Carrying Amount Level 1 Level 2 Level 3 September 30, 2019 ASSETS Cash, cash equivalents and restricted cash $ 42,171 $ 42,171 $ — $ — Investments, at cost, in 50% or less owned companies (included in other assets) 132 see below LIABILITIES Long-term debt, including current portion 399,219 — 382,367 — December 31, 2018 ASSETS Cash, cash equivalents and restricted cash $ 93,254 $ 93,254 $ — $ — Investments, at cost, in 50% or less owned companies (included in other assets) 132 see below LIABILITIES Long-term debt, including current portion 404,666 — 388,949 — The carrying value of cash, cash equivalents and restricted cash approximates fair value. The fair value of the Company’s long-term debt was estimated based upon quoted market prices or by using discounted cash flow analysis 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, 2019 were as follows (in thousands); Level 1 Level 2 Level 3 ASSETS Property and equipment: AHTS $ — $ 1,210 $ — FSVs — 2,490 — Property and equipment . During the nine months ended September 30, 2019, the Company recognized impairment charges of $11.7 million primarily associated with certain vessels (see Note 1). The Level 2 fair values were determined based on the sales prices of similar property and equipment as scrap value.

Warrants

Warrants	9 Months Ended
	Sep. 30, 2019
Warrants And Rights Note Disclosure [Abstract]
Warrants	10 . On April 26, 2018, the Company closed a private placement of its Common Stock and Warrants to purchase its Common Stock (which were issued to certain investors in place of Common Stock to facilitate compliance with Jones Act restrictions) for aggregate gross proceeds of $56,855,000 (the “PIPE Private Placement”) with certain qualified institutional buyers and other accredited investors. The PIPE Private Placement included the issuance of 2,168,586 shares of Common Stock and Warrants to purchase 674,164 shares of the Common Stock at an exercise price of $0.01 per share (the “PIPE Warrants”). The PIPE Warrants were issued to Proyectos Globales de Energía y Servicios CME, S.A. de C.V. a variable capital corporation (sociedad anónima de capital variable) incorporated and existing under the laws of the United Mexican States (“CME”) on April 26, 2018, have a 25-year term and an exercise price of $0.01 per share. On May 2, 2018, the Company and Carlyle entered into an amendment and exchange agreement pursuant to which Carlyle exchanged $50.0 million in principal amount of the Convertible Senior Notes for warrants to purchase 1,886,292 shares of Common Stock at an exercise price of $0.01 per share (the “Exchange Warrants” and, together with the PIPE Warrants, the “Warrants”). The Exchange Warrants have a 25-year term, which commenced May 2, 2018. On May 31, 2018, June 8, 2018, May 28, 2019 and June 14, 2019, 250,693, 38,857, 380,000 and 64,440 of the PIPE Warrants were exercised, respectively for $0.01 per share, which left 1,826,966 Warrants outstanding as of September 30, 2019. In conjunction with the exercise of Warrants on June 14, 2019, 49 shares of Common Stock were withheld as payment for the exercise price of the Warrants.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2019
Disclosure Text Block [Abstract]
Stockholders' Equity	1 1 . The impact of adopting ASC 842 resulted in an increase of $10.4 million, net of tax, to the Company’s opening retained earnings for the current period. On January 9, 2019, certain indirect wholly owned subsidiaries of SEACOR Marine acquired three FSVs in exchange for the private placement of 603,872 shares of its Common Stock to domestic U.S. holders affiliated with the McCall family of Louisiana. The value of the vessels and the Common Stock was $7.8 million based on the closing price of a share of Common Stock on the NYSE on the day of the exchange. The Common Stock was issued in reliance upon the exemption from registration provided by Section 4(a)(2) of the Securities Act. The Company has operated the acquired vessels for the past ten years under a revenue sharing pooling agreement that included four of its owned FSVs of similar specification. In accordance with its terms, this pooling agreement was terminated. On January 25, 2019, Seabulk Overseas Transport, Inc., a wholly owned subsidiary of SEACOR Marine (“Seabulk Overseas”), acquired a 6.25% minority interest in Windcat Workboats that it did not previously own upon the exercise of certain put options by one of the two minority owners pursuant to the terms of a subscription and shareholders agreement, as amended (the “Subscription and Shareholders Agreement”), in exchange for consideration of £1.5 million (approximately $2.0 million) in cash. The Company acquired the other 6.25% minority interest in Windcat Workboats that the Company did not already own on March 15, 2019 in exchange for consideration of 50,000 shares of Common Stock and €1.2 million (approximately $1.4 million) in cash. The Common Stock was issued in a private placement in reliance upon the exemption from registration provided by Section 4(a)(2) of the Securities Act. The two acquisitions resulted in Seabulk Overseas owning (and SEACOR Marine indirectly owning) 100% of Windcat Workboats.

Noncontrolling Interests in Sub

Noncontrolling Interests in Subsidiaries	9 Months Ended
	Sep. 30, 2019
Disclosure Text Block [Abstract]
Noncontrolling Interests in Subsidiaries	1 2 . Noncontrolling interests in the Company’s consolidated subsidiaries were as follows (in thousands): Noncontrolling Interests September 30, 2019 December 31, 2018 Falcon Global Holdings 28% $ 22,580 $ 26,989 Windcat Workboats 0% (1) — 2,115 Other 1.8% 315 300 $ 22,895 $ 29,404 (1) As of September 30, 2019; at December 31, 2018, noncontrolling interest was 12.5%. Falcon Global Holdings. The Company consolidates Falcon Global Holdings LLC (“FGH”) as the Company holds 72% of the equity interest in FGH and is entitled to appoint a majority of the board of managers of FGH. During the nine months ended September 30, 2019 and 2018, the net loss of FGH was $30.1 million and $14.2 million, respectively, of which $8.4 million and $4.0 million, respectively, was attributable to noncontrolling interests. Windcat Workboats. Prior to January 25, 2019, Seabulk Overseas, owned 87% of Windcat Workboats. On January 25, 2019, Seabulk Overseas acquired a 6.25% minority interest in Windcat Workboats that it did not previously own. Seabulk Overseas acquired the remaining 6.25% interest in Windcat Workboats that the Company did not already own on March 15, 2019. For the nine months ended September 30, 2018, the net loss of Windcat Workboats was $2.0 million and $0.2 million was attributed to noncontrolling interests.

Commitment and Contingencies

Commitment and Contingencies	9 Months Ended
	Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	1 3 . COMMITMENTS AND CONTINGENCIES As of September 30, 2019, the Company’s unfunded capital commitments were $71.9 million for two CTVs and three PSVs. Of the amount of unfunded capital commitments, $17.7 million is payable during the remainder of 2019 and $23.8 million is payable during 2020. The Company has indefinitely deferred an additional $30.4 million of orders with respect to three FSVs for which the Company had previously reported unfunded capital commitments. As of September 30, 2019, the Company has guaranteed certain performance contracts of one of its subsidiaries by setting aside £0.9 million from its available borrowing under an unsecured line of credit. If the contract is not fulfilled, the line of credit will be drawn to fund the guarantee. As of September 30, 2019, SEACOR Holdings Inc. (“SEACOR Holdings”), the Company’s former parent company, has guaranteed $27.0 million on behalf of the Company for various obligations including: performance obligations under sale-leaseback arrangements and invoiced amounts for funding deficits under the U.K. Merchant Navy Officers Pension Fund (“MNOPF”). Pursuant to a Distribution Agreement with SEACOR Holdings, SEACOR Holdings charges the Company a fee of 0.5% on outstanding guaranteed amounts, which declines as the obligations are settled by the Company. On February 8, 2018, Falcon Global USA LLC (“FGUSA”), a wholly owned subsidiary of FGH, entered into a $131.1 million credit agreement comprised of a $116.1 million term loan (the “FGUSA Term Loan”) and a $15.0 million revolving loan facility (the “FGUSA Revolving Loan Facility”) bearing interest at a variable rate (currently 6.3125%), maturing in 2024 and secured by 15 vessels owned by wholly owned subsidiaries of FGUSA (collectively, the “FGUSA Credit Facility”). The FGUSA Credit Facility, apart from a guarantee of certain interest payments and participation fees that expires on February 8, 2020, is non-recourse to SEACOR Marine and its subsidiaries other than FGUSA. FGUSA is currently in discussions with the lenders under the FGUSA Credit Facility with respect to its compliance with certain financial covenants under the FGUSA Credit Facility in 2020 after the expiration of the guarantee by SEACOR Marine. In 2015, the Brazilian Federal Revenue Office issued a tax-deficiency notice to In the normal course of its business, the Company becomes involved in various other litigation matters including, among others, 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.

Stock Based Compensation

Stock Based Compensation	9 Months Ended
	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Based Compensation	1 4 . STOCK BASED COMPENSATION Transactions in connection with the Company's 2017 Equity Incentive Plan during the nine months ended September 30, 2019 were as follows: Restricted Stock Activity: Outstanding as of December 31, 2018 192,346 Granted 321,100 Vested 116,796 Forfeited 1,000 Outstanding as of September 30, 2019 395,650 Stock Option Activity: Outstanding as of December 31, 2018 805,566 Granted 189,878 Exercised 86,494 Forfeited 5,000 Outstanding as of September 30, 2019 903,950 For the nine months ended September 30, 2019, the Company acquired for treasury 38,448 shares of Common Stock for an aggregate purchase price of $0.5 million from its employees to cover their tax withholding obligations upon the lapsing of restrictions on share awards. These shares were purchased in accordance with the terms of the Company's 2017 Equity Incentive Plan.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Segment Information	1 5 . SEGMENT INFORMATION The Company’s segment presentation and basis of measurement of segment profit or loss are as previously described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018. Certain reclassifications 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 Assets Held for Sale (see Notes 1 and 16). The following tables summarize the operating results, capital expenditures and assets of the Company’s reportable segments for the periods indicated (in thousands): United States (primarily Gulf of Mexico) Africa (primarily West Africa) Middle East and Asia Latin America Europe, Continuing Operations Total For the Three Months Ended September 30, 2019 Operating Revenues: Time charter $ 10,914 $ 11,738 $ 14,798 $ 1,951 $ 10,346 $ 49,747 Bareboat charter 597 — — 1,168 — 1,765 Other marine services 838 129 414 221 1,586 3,188 12,349 11,867 15,212 3,340 11,932 54,700 Direct Costs and Expenses: Operating: Personnel 4,353 3,308 4,023 846 3,349 15,879 Repairs and maintenance 1,508 1,323 1,387 298 979 5,495 Drydocking 547 (53 ) 20 — 1 515 Insurance and loss reserves 371 230 333 31 233 1,198 Fuel, lubes and supplies 739 961 701 187 322 2,910 Other 88 499 567 (87 ) 147 1,214 7,606 6,268 7,031 1,275 5,031 27,211 Direct Vessel Profit, from Continuing Operations $ 4,743 $ 5,599 $ 8,181 $ 2,065 $ 6,901 27,489 Other Costs and Expenses: Lease expense $ 2,758 $ 761 $ 43 $ — $ 609 4,171 Administrative and general 12,509 Depreciation and amortization 5,634 2,681 3,914 1,573 2,289 16,091 32,771 Gain on Asset Dispositions and Impairments 861 Operating Loss, for Continuing Operations $ (4,421 ) United States (primarily Gulf of Mexico) Africa (primarily West Africa) Middle East and Asia Latin America Europe, Continuing Operations Total For the Nine Months Ended September 30, 2019 Operating Revenues: Time charter $ 31,547 $ 32,911 $ 40,472 $ 8,919 $ 23,987 $ 137,836 Bareboat charter 830 — — 3,467 — 4,297 Other marine services 3,290 245 991 1,129 4,634 10,289 35,667 33,156 41,463 13,515 28,621 152,422 Direct Costs and Expenses: Operating: Personnel 14,059 10,603 12,569 3,378 9,807 50,416 Repairs and maintenance 6,801 3,459 6,209 1,114 3,103 20,686 Drydocking 4,342 237 454 47 2 5,082 Insurance and loss reserves 1,804 682 1,041 232 616 4,375 Fuel, lubes and supplies 2,529 2,654 2,135 929 671 8,918 Other 291 3,378 2,460 994 1,147 8,270 29,826 21,013 24,868 6,694 15,346 97,747 Direct Vessel Profit, from Continuing Operations $ 5,841 $ 12,143 $ 16,595 $ 6,821 $ 13,275 54,675 Other Costs and Expenses: Lease expense $ 8,611 $ 2,333 $ 131 $ 1 $ 1,560 12,636 Administrative and general 36,148 Depreciation and amortization 16,473 7,796 12,437 5,168 6,726 48,600 97,384 Loss on Asset Dispositions and Impairments (2,719 ) Operating Loss, for Continuing Operations $ (45,428 ) As of September 30, 2019 Property and Equipment: Historical cost $ 329,913 $ 221,080 $ 297,735 $ 108,224 $ 113,422 $ 1,070,374 Accumulated depreciation (161,315 ) (64,748 ) (74,225 ) (50,928 ) (49,412 ) (400,628 ) $ 168,598 $ 156,332 $ 223,510 $ 57,296 $ 64,010 $ 669,746 Total Assets (1) $ 251,547 $ 167,714 $ 257,294 $ 125,138 $ 92,861 $ 894,554 (1) Total assets by region does not include corporate assets of $145,952 as of September 30, 2019. United States (primarily Gulf of Mexico) Africa (primarily West Africa) Middle East and Asia Latin America Europe, Continuing Operations Total For the Three Months Ended September 30, 2018 Operating Revenues: Time charter $ 12,800 $ 11,201 $ 12,590 $ 7,479 $ 6,796 $ 50,866 Bareboat charter — — — 1,168 — 1,168 Other 2,722 1,777 (83 ) 416 1,303 6,135 15,522 12,978 12,507 9,063 8,099 58,169 Direct Costs and Expenses: Operating: Personnel 4,853 4,486 4,361 1,662 3,804 19,166 Repairs and maintenance 1,801 2,438 2,091 312 939 7,581 Drydocking 375 1,201 352 103 1,635 3,666 Insurance and loss reserves 612 323 385 163 140 1,623 Fuel, lubes and supplies 1,120 1,081 892 427 195 3,715 Other 154 1,103 952 350 90 2,649 8,915 10,632 9,033 3,017 6,803 38,400 Direct Vessel Profit, from Continuing Operations $ 6,607 $ 2,346 $ 3,474 $ 6,046 $ 1,296 $ 19,769 Other Costs and Expenses: Lease expense $ 2,078 $ 1,061 $ 57 $ 1 $ 95 $ 3,292 Administrative and general 11,767 Depreciation and amortization 5,227 2,381 4,207 2,521 2,061 16,397 31,456 Loss on Asset Dispositions and Impairments (1,765 ) Operating Loss, for Continuing Operations $ (13,452 ) United States (primarily Gulf of Mexico) Africa (primarily West Africa) Middle East and Asia Latin America Europe, Continuing Operations Total For the Nine Months Ended September 30, 2018 Operating Revenues: Time charter $ 27,834 $ 33,117 $ 37,555 $ 13,409 $ 17,077 $ 128,992 Bareboat charter — — — 3,467 — 3,467 Other marine services 6,053 3,414 (1,005 ) 1,371 2,378 12,211 33,887 36,531 36,550 18,247 19,455 144,670 Direct Costs and Expenses: Operating: Personnel 13,481 12,873 12,452 3,257 8,426 50,489 Repairs and maintenance 4,024 5,457 8,095 649 2,481 20,706 Drydocking 1,810 2,113 413 114 2,220 6,670 Insurance and loss reserves 1,948 789 982 399 348 4,466 Fuel, lubes and supplies 2,513 2,650 2,848 841 696 9,548 Other 208 3,541 2,996 898 317 7,960 23,984 27,423 27,786 6,158 14,488 99,839 Direct Vessel Profit, from Continuing Operations $ 9,903 $ 9,108 $ 8,764 $ 12,089 $ 4,967 44,831 Other Costs and Expenses: Lease expense $ 6,187 $ 3,222 $ 175 $ 4 $ 293 9,881 Administrative and general 39,182 Depreciation and amortization $ 17,677 $ 8,112 $ 14,608 $ 6,020 $ 6,523 52,940 102,003 Loss on Asset Dispositions and Impairments (3,493 ) Operating Loss, for Continuing Operations $ (60,665 ) As of September 30, 2018 Property and Equipment: Historical cost $ 479,303 $ 186,729 $ 310,110 $ 102,776 $ 69,924 $ 1,148,842 Accumulated depreciation (242,364 ) (53,498 ) (81,121 ) (47,374 ) (42,062 ) (466,419 ) $ 236,939 $ 133,231 $ 228,989 $ 55,402 $ 27,862 $ 682,423 Total Assets (1) $ 377,798 $ 144,325 $ 261,531 $ 125,720 $ 19,893 $ 929,267 (1) The Company’s investments in 50% or less owned companies, which are accounted for under the equity method, also contribute to its consolidated results of operations. As of September 30, 2019, and 2018, the Company’s investments, at equity and advances to 50% or less owned companies in its other 50% or less owned companies were $107.3 million and $118.5 million, respectively. Equity in (losses) earnings of 50% or less owned companies for the nine months ended September 30, 2019 and 2018 were ($11.9) million and ($1.7) million, respectively.

Assets Held for Sale

Assets Held for Sale	9 Months Ended
	Sep. 30, 2019
Discontinued Operations And Disposal Groups [Abstract]
Assets Held for Sale	16. The Company’s assets held for sale consist of BPOS and following the completion of the Sale, the Company will have no continuing involvement in this business (see Note 1). Summarized selected operating result of the Company’s assets held for sale were as follows (in thousands): September 30, December 31, 2019 2018 Boston Putford Offshore Safety Ltd Assets from Discontinued Operations: Current assets $ 13,130 $ 15,225 Net property and equipment 16,262 26,277 29,392 41,502 Total current liabilities $ 3,813 $ 2,526 Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Boston Putford Offshore Safety Ltd Operating Revenues: Time charter $ 11,223 $ 12,036 $ 34,034 $ 37,878 Other revenue (11 ) 50 50 129 11,212 12,086 34,084 38,007 Costs and Expenses: Operating 9,847 10,198 27,113 33,087 Direct Vessel Profit 1,365 1,888 6,971 4,920 Depreciation 1,035 945 3,213 2,320 (Loss) Gain on Asset Dispositions and Impairments, Net (7,084 ) 2,351 (6,993 ) 2,491 Operating (Loss) Income (6,754 ) 3,294 (3,235 ) 5,091 Other Income (Expense) Interest income — 4 10 8 Interest expense (55 ) (101 ) (184 ) (306 ) Foreign currency translation loss (42 ) (6 ) (82 ) (14 ) (97 ) (103 ) (256 ) (312 ) Operating (Loss) Income Before Equity Earnings of 50% or Less Owned Companies, Net of Tax $ (6,851 ) $ 3,191 $ (3,491 ) $ 4,779 Income Tax Expense — 1 4 5 Operating (Loss) Income Before Equity Earnings of 50% or Less Owned Companies $ (6,851 ) $ 3,190 $ (3,495 ) $ 4,774 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 17 (5 ) 168 194 Net (Loss) Income from Discontinued Operations $ (6,834 ) $ 3,185 $ (3,327 ) $ 4,968 Upon completion of the anticipated sale of the ERRV business, the Company anticipates a loss on sale of approximately $7.1 million. As of November 1, 2019, the date the SPA was signed, based on changes in the exchange rate between GBP and USD, the loss on sale would have been $5.6 million, a reduction in this loss on sale of $1.5 million.

Basis of Presentation and Acc_2

Basis of Presentation and Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
Basis Of Presentation And Accounting Policies [Abstract]
Consolidation	The condensed consolidated financial statements include the accounts of SEACOR Marine Holdings Inc. and its consolidated subsidiaries (the “Company”). In the opinion of management, all adjustments (consisting of normal recurring adjustments) have been made to fairly present the unaudited condensed consolidated financial statements for the periods indicated. 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 Company’s financial statements and related notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2018. Unless the context otherwise indicates, any reference in this Quarterly Report on Form 10-Q to the “Company” refers to SEACOR Marine Holdings Inc. and its consolidated subsidiaries and any reference in this Quarterly Report on Form 10-Q to “SEACOR Marine” refers to SEACOR Marine Holdings Inc. without its consolidated subsidiaries.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards. On February 25, 2016, the Financial Accounting Standards Board (“FASB”) issued a comprehensive new leasing standard, ASC 842, 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. It also requires additional disclosures about leasing arrangements. The Company adopted the new standard on January 1, 2019 and applied the transition provisions of the new standard with recognition of a cumulative-effect adjustment to the opening balance of retained earnings and therefore the Company was not required to recast previously issued financial statements. The Company elected the available practical expedients permitted under the guidance including the ability to carry forward the existing lease classification, the option to not separate lease and non-lease components in calculating the right-of-use assets and corresponding lease liabilities and to not apply the recognition requirements of Topic 842 to short-term leases (leases that have a duration of twelve months or less at lease inception). For some leases, it was not possible for the Company to determine the interest rate implicit in each of its operating leases and therefore used the Company’s incremental borrowing rate in calculating operating lease right-of-use assets and lease liabilities. The Company included renewal options that were reasonably certain of being exercised in determining the lease term. Upon adoption, the Company recorded $33.7 million of right-of-use assets, $31.9 million in lease liabilities, and a cumulative-effect adjustment to the opening balance of retained earnings of $1.7 million for certain of the Company’s equipment, office and land leases. In addition, unamortized deferred gains for four vessels previously accounted for under sale-leaseback arrangements of $8.7 million, ($11.0 million deferred gains net of $2.3 million deferred taxes), were fully recognized as an adjustment to the opening balance of retained earnings. In February 2018, the FASB issued ASU 2018-02, “Income Statement—Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income” (“ASU 2018-02”). The amendments in ASU 2018-02 permit a reclassification from Accumulated Other Comprehensive Income (“AOCI”) to retained earnings for stranded tax effects resulting from the Tax Cuts & Jobs Act (“TCJA”). Consequently, the amendments eliminate the stranded tax effects resulting from the Tax Act and will improve the usefulness of information reported to financial statement users. ASU 2018-02 is effective for the Company for annual and interim reporting periods beginning after December 15, 2018. For the period ending September 30, 2019, an election has not been made to reclassify the income tax effects of the TCJA from AOCI to retained earnings. In June 2018, the FASB issued ASU 2018-07, a new accounting standard which addresses aspects of the accounting for nonemployee share-based payment transactions. The standard is effective for interim and annual periods beginning after December 15, 2018. The adoption of the new standard by the Company did not have a material impact on its consolidated financial position or its results of operations and cash flows.
Assets Held for Sale	Assets Held for Sale. On November 1, 2019, SEACOR Capital (UK) Limited (“SEACAP”), a wholly owned subsidiary of SEACOR Marine, entered into a sale and purchase agreement (“SPA”) to sell the Company’s North Sea emergency response and rescue vessel (“ERRV”) business to North Star Holdco Limited (“North Star”) through the sale of 100% of the equity of its subsidiary, Boston Putford Offshore Safety Limited (“BPOS” and together with its subsidiaries, the “BPOS Group”), upon the terms and subject to the conditions set forth in the SPA (“the Sale”). As consideration for the Sale, at the closing of the transaction, North Star will pay SEACAP an aggregate purchase price equal to approximately £19.5 million (equivalent to approximately US$25.1 million based on the USD to GDP closing exchange rate on October 31, 2019) subject to adjustment for continued intercompany services provided and interest calculated from July 31, 2019. Additional consideration of up to £4.0 million (equivalent to approximately US$5.2 million based on the same exchange rate) may be payable to SEACAP based on revenue targets being achieved in 2020 and 2021. For all periods presented herein, the Company has reported the historical position, results of operations and cash flows of BPOS as Assets Held for Sale (see Note 16).
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 over control of the promised goods or services to its customers. Costs to obtain or fulfill a contract are expensed as incurred. Lease Revenues. The Company’s lease revenues are primarily from time charters and bareboat charters that are recognized ratably over the lease term as services are provided, typically on a per day basis. The charterer will take the vessel on hire for a specific period of time, use the vessel to move cargo, people or equipment and will pay the Company the agreed upon rate per day. Under a time charter the Company provides a vessel to a customer for a set term and the Company 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, including fuel, and the risk of operation (see Note 15). Revenues from Customers of Management Services. The Company contracts with various customers to carry out management services for vessels as agents for and on behalf of ship owners. These services include crew management, technical management, commercial management, insurance arrangements, sale and purchase of vessel, provisions and bunkering. As manager, the Company undertakes to use its best endeavors to provide the agreed management services as agents for, and on behalf of the ship owners in accordance with sound ship management practice and to protect and promote the interest of the owners in all matters relating to the provision of the agreed upon management services. The Company also contracts with various customers to carry out management services regarding engineering for vessel construction and vessel conversions. The majority of the ship management agreements have a duration of one to three years and are typically billed monthly. The Company 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 (see Note 15). Revenue that does not meet the aforementioned criteria is deferred until the criteria is met and are considered contract liabilities. Contract liabilities which are included in other current liabilities in the accompanying condensed consolidated balance sheets, for the nine months ended September 30 were as follows (in thousands): 2019 2018 Balance at beginning of period $ 1,327 $ 10,104 Revenues deferred during the period 5,022 2,756 Revenues recognized during the period (3,046 ) (3,191 ) Balance at end of period $ 3,303 $ 9,669 As of September 30, 2019, contract liabilities include $1.9 million related to the time charter of an offshore support vessel to a customer for which collection was not reasonably assured. The Company will recognize revenues when collected or when collection is reasonably assured. All costs and expenses related to this charter were recognized as incurred. As of September 30, 2019, the Company has deferred $1.2 million received as reimbursement for upgrades of a vessel and deferred reservation fees. The amount will be recognized as revenues over time, commencing with the start of the new time charter agreement for the vessel. The remaining balance of $0.2 million as of September 30, 2019 is comprised of contract liabilities to two customers for which collection is not reasonably assured.
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 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, 2019, the estimated useful life (in years) of each of the Company’s major categories of new equipment was as follows: Offshore Support Vessels: Crew transfer vessels 10 All other offshore support vessels (excluding crew transfer vessels) 20 Equipment maintenance and repair costs and the costs of routine overhauls, drydockings and inspections performed on vessels and equipment are charged to operating expense as incurred. Expenditures that extend the useful life or improve the marketing and commercial characteristics of equipment as well as major renewals and improvements to other properties are capitalized. Certain interest costs incurred during the construction of equipment are capitalized as part of the assets’ carrying values and are amortized over such assets’ estimated useful lives. During the nine months ended September 30, 2019, capitalized interest totaled $1.2 million.
Impairment of Long-Lived Assets and 50% or Less Owned Companies	Impairment of Long-Lived Assets. The Company performs an impairment analysis of long-lived assets used in operations, including intangible assets, when indicators of impairment are present. These indicators may include a significant decrease in the market price of a long-lived asset or asset group, a significant adverse change in the extent or manner in which a long-lived asset or asset group is being used or in its physical condition, or a current period operating or cash flow loss combined with a history of operating or cash flow losses or a forecast that demonstrates continuing losses associated with the use of a long-lived asset or asset group. If the carrying values of the assets are not recoverable, as determined by the estimated undiscounted cash flows, the estimated fair value of the assets or asset groups are compared to their current carrying values and impairment charges are recorded if the carrying value exceeds fair value. The Company performs its testing on an asset or asset group basis. Generally, fair value is determined using valuation techniques, such as expected undiscounted cash flows or appraisals, as appropriate. During the nine months ended September 30, 2019, the Company recognized $11.7 million of impairment charges primarily related to two anchor-handling towing supply (“AHTS”) vessels previously removed from service and adjusted to scrap value, two AHTS vessels and four fast support vessels (“FSV”) each of which has been adjusted to indicative sales price, and two leased-in vessels (one AHTS and one platform supply vessel (“PSV”)), adjusted for indicative future cash flows. During the nine months ended September 30, 2018, the Company recognized $3.0 million of impairment charges primarily related to four AHTS vessels removed from service and adjusted to scrap value. Impairment of 50% 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, 2019, the Company did not recognize any impairment charges related to its 50% or less owned companies. During the nine months ended September 30, 2018, the Company recognized impairment charges of $1.2 million related to one of its 50% or less owned companies which the Company believed was unable to meet all of its’ liabilities.
Income Taxes	Income Taxes. During the nine months ended September 30, 2019, the Company's effective income tax rate of 8.3% was primarily due to taxes provided on income attributable to noncontrolling interests, foreign sourced income not subject to U.S. income taxes, foreign taxes not creditable against U.S. income taxes, and the annual return-to-accrual adjustment for the prior year.
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. In 2018, 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 and were amortized in operating expenses as a reduction to rental expense. The new lease accounting pronouncement which was adopted on January 1, 2019 required the recognition of unamortized gains as a cumulative-effect adjustment to the opening balance of retained earnings. Deferred gain activity related to these transactions for the nine months ended September 30 was as follows (in thousands): 2019 2018 Balance at beginning of period $ 11,819 $ 25,006 Amortization of deferred gains included in operating expenses as a reduction to rental expense — (6,053 ) Impact of adoption of new accounting standard (11,026 ) — Other adjustments (390 ) (416 ) Balance at end of period $ 403 $ 18,537
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss). The components of accumulated other comprehensive loss were as follows (in thousands): SEACOR Marine Holdings Inc. Stockholders’ Equity Noncontrolling Interests Foreign Currency Translation Adjustments Derivative Losses on Cash Flow Hedges, net Total Foreign Currency Translation Adjustments Derivative Income (Losses) on Cash Flow Hedges, net Other Comprehensive Loss December 31, 2018 $ (15,472 ) $ (1,316 ) $ (16,788 ) $ (1,445 ) $ (11 ) — Other comprehensive loss (1,902 ) (2,415 ) (4,317 ) — — $ (4,317 ) Nine Months Ended September 30, 2019 $ (17,374 ) $ (3,731 ) $ (21,105 ) $ (1,445 ) $ (11 ) $ (4,317 )
Leases	Leases. The Company determines if an arrangement contains a lease at the inception of a contract. Leases with contractual terms less than twelve months are not recorded on the balance sheet and lease expense is recognized on a straight-line basis over the term of the short-term lease. Leases with contractual terms longer than twelve months are categorized as either operating or finance, with corresponding right-of-use asset and lease liability recorded on the balance sheet. Finance leases are generally those leases that substantially utilize or pay for the entire asset over its estimated life. All other leases are categorized as operating leases. Right-of-use assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Lease liabilities are recognized at the present value of the fixed lease payments, using an implicit discount rate if available, or if not readily available, the Company’s incremental borrowing rate. Right-of-use assets are recognized based on the initial present value of the fixed lease payments and are tested for impairment in the same manner as long-lived assets used in operations. When options exist to extend the lease term, terminate the lease before the contractual expiration date, or purchase the leased asset, and it is reasonably certain that these options will be exercised, the options are considered in determining the classification and measurement of the lease.
Loss Per Share	Loss Per Share. Basic loss per common share of the Company is computed based on the weighted average number of common shares and warrants to purchase common shares at an exercise price of $0.01 per share (“Warrants”) issued and outstanding during the relevant periods. The Warrants are included in the basic loss per common share because the shares issuable upon exercise of the Warrants are issuable for de minimis cash consideration and therefore not anti-dilutive. Diluted loss per common share of the Company is computed based on the weighted average number of common shares and Warrants issued and outstanding plus the effect of other potentially dilutive securities through the application of the treasury stock method and the if-converted method that assumes all common shares have been issued and outstanding during the relevant periods pursuant to the conversion of the Convertible Senior Notes. For the nine months ended September 30, 2019 and 2018, diluted earnings per common share of the Company excluded 2,183,708 common shares, respectively, issuable pursuant to the Company’s Convertible Senior Notes (see Note 5) as the effect of their inclusion in the computation would be anti-dilutive. In addition, for the nine months ended September 30, 2019 and 2018, diluted loss per common share of the Company excluded 282,050 and 196,338 shares of restricted stock, respectively, and 397,119 and 732,191 shares of stock, respectively, issuable upon exercise of outstanding stock options as the effect of their inclusion in the computation would be anti-dilutive.
New Accounting Pronouncements	New Accounting Pronouncements. In August 2018, the FASB issued ASU 2018-13, a new accounting standard which modifies the disclosure requirements related to fair value measurement. The new guidance is effective for fiscal years beginning after December 15, 2019. The effects of this standard on our financial position or reporting is not expected to be material. In August 2018, the FASB issued ASU 2018-15, a new accounting standard which provided guidance regarding the accounting for fees paid by a customer in a cloud computing arrangement (hosting arrangement). The guidance reduces complexity for the accounting for costs of implementing a cloud computing service arrangement and aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The standard is effective for interim and annual periods beginning after December 15, 2019. The Company is evaluating the provisions of the standard but does not expect the adoption of the new standard to have a material impact on its consolidated financial position or its results of operations and cash flows. In June 2016, the FASB issued ASU 2016-13, an amendment to the accounting standards which replaces the current incurred loss impairment methodology for financial assets measured at amortized cost with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information, including forecasted information, to develop credit loss estimates. The new standard is effective for interim periods beginning after December 15, 2019. Early adoption is permitted for annual periods beginning after December 15, 2018. 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. Reclassification . Certain amounts in the prior year’s condensed consolidated financial statements have been reclassified to conform to the current year presentation. The reclassification had no impact on total assets, liabilities, or net loss.

Basis of Presentation and Acc_3

Basis of Presentation and Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2019
Basis Of Presentation And Accounting Policies [Abstract]
Schedule of Deferred Revenues	Revenue that does not meet the aforementioned criteria is deferred until the criteria is met and are considered contract liabilities. Contract liabilities which are included in other current liabilities in the accompanying condensed consolidated balance sheets, for the nine months ended September 30 were as follows (in thousands): 2019 2018 Balance at beginning of period $ 1,327 $ 10,104 Revenues deferred during the period 5,022 2,756 Revenues recognized during the period (3,046 ) (3,191 ) Balance at end of period $ 3,303 $ 9,669
Schedule of Property and Equipment Useful Life	As of September 30, 2019, the estimated useful life (in years) of each of the Company’s major categories of new equipment was as follows: Offshore Support Vessels: Crew transfer vessels 10 All other offshore support vessels (excluding crew transfer vessels) 20
Schedule of Deferred Gain Activity	Deferred gain activity related to these transactions for the nine months ended September 30 was as follows (in thousands): 2019 2018 Balance at beginning of period $ 11,819 $ 25,006 Amortization of deferred gains included in operating expenses as a reduction to rental expense — (6,053 ) Impact of adoption of new accounting standard (11,026 ) — Other adjustments (390 ) (416 ) Balance at end of period $ 403 $ 18,537
Schedule of Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Income (Loss). The components of accumulated other comprehensive loss were as follows (in thousands): SEACOR Marine Holdings Inc. Stockholders’ Equity Noncontrolling Interests Foreign Currency Translation Adjustments Derivative Losses on Cash Flow Hedges, net Total Foreign Currency Translation Adjustments Derivative Income (Losses) on Cash Flow Hedges, net Other Comprehensive Loss December 31, 2018 $ (15,472 ) $ (1,316 ) $ (16,788 ) $ (1,445 ) $ (11 ) — Other comprehensive loss (1,902 ) (2,415 ) (4,317 ) — — $ (4,317 ) Nine Months Ended September 30, 2019 $ (17,374 ) $ (3,731 ) $ (21,105 ) $ (1,445 ) $ (11 ) $ (4,317 )

Transformation, Facility Rest_2

Transformation, Facility Restructuring and Severance Charges (Tables)	9 Months Ended
	Sep. 30, 2019
Restructuring And Related Activities [Abstract]
Schedule of Components of Restructuring Charges By Segment	The components of restructuring charges by segment for the three and nine months ended September 30, 2019 were as follows (in thousands): United States (primarily Gulf of Mexico) Africa (primarily West Africa) Middle East and Asia Latin America Europe (primarily North Sea) Total Transformation Plan Severance Charges $ 2,937 $ — $ — $ — $ 119 $ 3,056 Other Charges 247 — — 1 — 248 Total Charges $ 3,184 $ — $ — $ 1 $ 119 $ 3,304
Schedule of Severance and Other Restructuring Charges	The severance and other restructuring charges gave rise to certain liabilities, the components of which are summarized in the following table (in thousands), and largely relate to liabilities accrued as part of the 2019 Transformation Plan that will be paid pursuant to the respective arrangements and statutory requirements. United States (primarily Gulf of Mexico) Africa (primarily West Africa) Middle East and Asia Latin America Europe (primarily North Sea) Total Transformation Plan Severance Liability $ 526 $ — $ — $ — $ 38 $ 564 Other Liability — — — — — — Total Liability $ 526 $ — $ — $ — $ 38 $ 564
Schedule of Cumulative Restructuring and Reorganization Cost Incurred to Date, Estimated Remaining and to be Incurred	The following table is a summary of the cumulative restructuring and reorganization cost incurred to date in operating charges and the estimated remaining restructuring and reorganization costs to be incurred as of September 30, 2019 (in thousands). Transformation Plan Cumulative restructuring costs incurred to date in operating charges $ 3,304 Estimated additional restructuring costs to be incurred 2,428 Total restructuring and reorganization costs incurred and to be incurred $ 5,732

Long-term Debt (Tables)

Long-term Debt (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule of Long-term Debt Obligations	The Company’s long-term debt obligations as of September 30, 2019 and December 31, 2018 were as follows (in thousands): September 30, 2019 December 31, 2018 Convertible Senior Notes $ 125,000 $ 125,000 SEACOR Marine Foreign Holdings Syndicated Credit Facility 117,000 126,750 Falcon Global USA Term Loan Facility 102,349 109,099 Sea-Cat Crewzer III Term Loan Facility 24,128 25,989 Windcat Workboats Facilities 23,751 24,850 Falcon Global USA Revolver 15,000 15,000 SEACOR 88/888 Term Loan 11,000 11,000 SEACOR Alps 10,626 — BNDES Equipment Construction Finance Notes 3,820 5,284 $ 432,674 $ 442,972 Portion due within one year (23,446 ) (16,812 ) Debt discount (27,805 ) (32,005 ) Issue costs (5,651 ) (6,301 ) $ 375,772 $ 387,854

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Summary of Future Minimum Payments For Operating Leases	As of September 30, 2019, future minimum payments for operating leases for the remainder of 2019 and the years ended December 31 were as follows (in thousands): Remainder of 2019 $ 4,897 2020 14,066 2021 7,120 2022 663 2023 622 Years subsequent to 2023 4,851 32,219 Interest component (4,159 ) 28,060 Current portion of long-term operating lease liabilities 15,182 Long-term operating lease liabilities $ 12,878
Summary of Components of Leases Expense	For the nine months ended September 30, 2019, the components of lease expense were as follows (in thousands): Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Operating lease expense $ 3,446 $ 10,669 Short-term lease expense (lease duration of twelve months or less at lease commencement) 725 1,967 $ 4,171 $ 12,636
Summary of Other Information Related to Operating Leases	For the nine months ended September 30, 2019, other information related to operating leases were as follows (in thousands except weighted average data): 2019 Operating cash flows from operating leases $ 14,671 Right-of-use assets obtained for operating lease liabilities $ 33,979 Weighted average remaining lease term, in years 4.9 Weighted average discount rate 4.2 %

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2019
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, 2019: Statutory rate 21.0 % Foreign taxes not creditable against U.S. income tax (5.4 ) Foreign earnings not subject to U.S. income tax (3.6 ) Return to provision (3.6 ) Noncontrolling interests (1.9 ) State taxes 1.6 Other 0.2 8.3 %

Derivative Instruments and He_2

Derivative Instruments and Hedging Strategies (Tables)	9 Months Ended
	Sep. 30, 2019
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Schedule of Fair Value of Derivative Assets and Liabilities	The fair values of the Company’s derivative instruments were as follows (in thousands): September 30, 2019 December 31, 2018 Derivative Asset Derivative Liability Derivative Asset Derivative Liability Derivatives designated as hedging instruments: Interest rate swap agreements (cash flow hedges) $ — $ 3,576 (1) $ — $ 1,659 (1) — 3,576 — 1,659 Derivatives not designated as hedging instruments: Conversion option liability on Convertible Senior Notes — 4,543 — 5,276 $ — $ 8,119 $ — $ 6,935 ( 1 ) Included in other current liabilities in the accompanying condensed consolidated balance sheets.
Schedule of (Losses) Gains on Derivative Instruments not Designated as Hedging Instruments	The Company recognized (losses) gains on derivative instruments not designated as hedging instruments for the nine months ended September 30 as follows (in thousands): 2019 2018 Conversion option liability on Convertible Senior Notes $ 734 $ (11,096 ) Interest rate swap agreements — 1,299 $ 734 $ (9,797 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis	The Company’s financial assets and liabilities as of September 30, 2019 that are measured at fair value on a recurring basis were as follows (in thousands): Level 1 Level 2 Level 3 September 30, 2019 ASSETS Construction reserve funds $ 18,161 $ — $ — LIABILITIES Derivative instruments — 3,576 — Conversion Option Liability on Convertible Senior Notes — — 4,543 December 31, 2018 ASSETS Construction reserve funds $ 28,221 $ — $ — LIABILITIES Derivative instruments — 1,659 — Conversion Option Liability on Convertible Senior Notes — — 5,276
Schedule of Estimated Fair Values of Financial Assets and Liabilities	The estimated fair values of the Company’s other financial assets and liabilities as of September 30, 2019 were as follows (in thousands): Estimated Fair Value Carrying Amount Level 1 Level 2 Level 3 September 30, 2019 ASSETS Cash, cash equivalents and restricted cash $ 42,171 $ 42,171 $ — $ — Investments, at cost, in 50% or less owned companies (included in other assets) 132 see below LIABILITIES Long-term debt, including current portion 399,219 — 382,367 — December 31, 2018 ASSETS Cash, cash equivalents and restricted cash $ 93,254 $ 93,254 $ — $ — Investments, at cost, in 50% or less owned companies (included in other assets) 132 see below LIABILITIES Long-term debt, including current portion 404,666 — 388,949 —
Schedule of Other Assets and Liabilities Measured at Fair Value	The Company’s other assets and liabilities that were measured at fair value during the nine months ended September 30, 2019 were as follows (in thousands); Level 1 Level 2 Level 3 ASSETS Property and equipment: AHTS $ — $ 1,210 $ — FSVs — 2,490 —

Noncontrolling Interests in S_2

Noncontrolling Interests in Subsidiaries (Tables)	9 Months Ended
	Sep. 30, 2019
Table [Text Block]
Schedule of Noncontrolling Interests in the Company's Consolidated Subsidiaries	Noncontrolling interests in the Company’s consolidated subsidiaries were as follows (in thousands): Noncontrolling Interests September 30, 2019 December 31, 2018 Falcon Global Holdings 28% $ 22,580 $ 26,989 Windcat Workboats 0% (1) — 2,115 Other 1.8% 315 300 $ 22,895 $ 29,404 (1) As of September 30, 2019; at December 31, 2018, noncontrolling interest was 12.5%.

Stock Based Compensation (Table

Stock Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Transactions in Connection with 2017 Equity Incentive Plan	Transactions in connection with the Company's 2017 Equity Incentive Plan during the nine months ended September 30, 2019 were as follows: Restricted Stock Activity: Outstanding as of December 31, 2018 192,346 Granted 321,100 Vested 116,796 Forfeited 1,000 Outstanding as of September 30, 2019 395,650 Stock Option Activity: Outstanding as of December 31, 2018 805,566 Granted 189,878 Exercised 86,494 Forfeited 5,000 Outstanding as of September 30, 2019 903,950

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	The following tables summarize the operating results, capital expenditures and assets of the Company’s reportable segments for the periods indicated (in thousands): United States (primarily Gulf of Mexico) Africa (primarily West Africa) Middle East and Asia Latin America Europe, Continuing Operations Total For the Three Months Ended September 30, 2019 Operating Revenues: Time charter $ 10,914 $ 11,738 $ 14,798 $ 1,951 $ 10,346 $ 49,747 Bareboat charter 597 — — 1,168 — 1,765 Other marine services 838 129 414 221 1,586 3,188 12,349 11,867 15,212 3,340 11,932 54,700 Direct Costs and Expenses: Operating: Personnel 4,353 3,308 4,023 846 3,349 15,879 Repairs and maintenance 1,508 1,323 1,387 298 979 5,495 Drydocking 547 (53 ) 20 — 1 515 Insurance and loss reserves 371 230 333 31 233 1,198 Fuel, lubes and supplies 739 961 701 187 322 2,910 Other 88 499 567 (87 ) 147 1,214 7,606 6,268 7,031 1,275 5,031 27,211 Direct Vessel Profit, from Continuing Operations $ 4,743 $ 5,599 $ 8,181 $ 2,065 $ 6,901 27,489 Other Costs and Expenses: Lease expense $ 2,758 $ 761 $ 43 $ — $ 609 4,171 Administrative and general 12,509 Depreciation and amortization 5,634 2,681 3,914 1,573 2,289 16,091 32,771 Gain on Asset Dispositions and Impairments 861 Operating Loss, for Continuing Operations $ (4,421 ) United States (primarily Gulf of Mexico) Africa (primarily West Africa) Middle East and Asia Latin America Europe, Continuing Operations Total For the Nine Months Ended September 30, 2019 Operating Revenues: Time charter $ 31,547 $ 32,911 $ 40,472 $ 8,919 $ 23,987 $ 137,836 Bareboat charter 830 — — 3,467 — 4,297 Other marine services 3,290 245 991 1,129 4,634 10,289 35,667 33,156 41,463 13,515 28,621 152,422 Direct Costs and Expenses: Operating: Personnel 14,059 10,603 12,569 3,378 9,807 50,416 Repairs and maintenance 6,801 3,459 6,209 1,114 3,103 20,686 Drydocking 4,342 237 454 47 2 5,082 Insurance and loss reserves 1,804 682 1,041 232 616 4,375 Fuel, lubes and supplies 2,529 2,654 2,135 929 671 8,918 Other 291 3,378 2,460 994 1,147 8,270 29,826 21,013 24,868 6,694 15,346 97,747 Direct Vessel Profit, from Continuing Operations $ 5,841 $ 12,143 $ 16,595 $ 6,821 $ 13,275 54,675 Other Costs and Expenses: Lease expense $ 8,611 $ 2,333 $ 131 $ 1 $ 1,560 12,636 Administrative and general 36,148 Depreciation and amortization 16,473 7,796 12,437 5,168 6,726 48,600 97,384 Loss on Asset Dispositions and Impairments (2,719 ) Operating Loss, for Continuing Operations $ (45,428 ) As of September 30, 2019 Property and Equipment: Historical cost $ 329,913 $ 221,080 $ 297,735 $ 108,224 $ 113,422 $ 1,070,374 Accumulated depreciation (161,315 ) (64,748 ) (74,225 ) (50,928 ) (49,412 ) (400,628 ) $ 168,598 $ 156,332 $ 223,510 $ 57,296 $ 64,010 $ 669,746 Total Assets (1) $ 251,547 $ 167,714 $ 257,294 $ 125,138 $ 92,861 $ 894,554 (1) Total assets by region does not include corporate assets of $145,952 as of September 30, 2019. United States (primarily Gulf of Mexico) Africa (primarily West Africa) Middle East and Asia Latin America Europe, Continuing Operations Total For the Nine Months Ended September 30, 2018 Operating Revenues: Time charter $ 27,834 $ 33,117 $ 37,555 $ 13,409 $ 17,077 $ 128,992 Bareboat charter — — — 3,467 — 3,467 Other marine services 6,053 3,414 (1,005 ) 1,371 2,378 12,211 33,887 36,531 36,550 18,247 19,455 144,670 Direct Costs and Expenses: Operating: Personnel 13,481 12,873 12,452 3,257 8,426 50,489 Repairs and maintenance 4,024 5,457 8,095 649 2,481 20,706 Drydocking 1,810 2,113 413 114 2,220 6,670 Insurance and loss reserves 1,948 789 982 399 348 4,466 Fuel, lubes and supplies 2,513 2,650 2,848 841 696 9,548 Other 208 3,541 2,996 898 317 7,960 23,984 27,423 27,786 6,158 14,488 99,839 Direct Vessel Profit, from Continuing Operations $ 9,903 $ 9,108 $ 8,764 $ 12,089 $ 4,967 44,831 Other Costs and Expenses: Lease expense $ 6,187 $ 3,222 $ 175 $ 4 $ 293 9,881 Administrative and general 39,182 Depreciation and amortization $ 17,677 $ 8,112 $ 14,608 $ 6,020 $ 6,523 52,940 102,003 Loss on Asset Dispositions and Impairments (3,493 ) Operating Loss, for Continuing Operations $ (60,665 ) As of September 30, 2018 Property and Equipment: Historical cost $ 479,303 $ 186,729 $ 310,110 $ 102,776 $ 69,924 $ 1,148,842 Accumulated depreciation (242,364 ) (53,498 ) (81,121 ) (47,374 ) (42,062 ) (466,419 ) $ 236,939 $ 133,231 $ 228,989 $ 55,402 $ 27,862 $ 682,423 Total Assets (1) $ 377,798 $ 144,325 $ 261,531 $ 125,720 $ 19,893 $ 929,267 (1)

Assets Held for Sale (Tables)

Assets Held for Sale (Tables)	9 Months Ended
	Sep. 30, 2019
Discontinued Operations And Disposal Groups [Abstract]
Schedule of Assets Held for Sale	Summarized selected operating result of the Company’s assets held for sale were as follows (in thousands): September 30, December 31, 2019 2018 Boston Putford Offshore Safety Ltd Assets from Discontinued Operations: Current assets $ 13,130 $ 15,225 Net property and equipment 16,262 26,277 29,392 41,502 Total current liabilities $ 3,813 $ 2,526 Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Boston Putford Offshore Safety Ltd Operating Revenues: Time charter $ 11,223 $ 12,036 $ 34,034 $ 37,878 Other revenue (11 ) 50 50 129 11,212 12,086 34,084 38,007 Costs and Expenses: Operating 9,847 10,198 27,113 33,087 Direct Vessel Profit 1,365 1,888 6,971 4,920 Depreciation 1,035 945 3,213 2,320 (Loss) Gain on Asset Dispositions and Impairments, Net (7,084 ) 2,351 (6,993 ) 2,491 Operating (Loss) Income (6,754 ) 3,294 (3,235 ) 5,091 Other Income (Expense) Interest income — 4 10 8 Interest expense (55 ) (101 ) (184 ) (306 ) Foreign currency translation loss (42 ) (6 ) (82 ) (14 ) (97 ) (103 ) (256 ) (312 ) Operating (Loss) Income Before Equity Earnings of 50% or Less Owned Companies, Net of Tax $ (6,851 ) $ 3,191 $ (3,491 ) $ 4,779 Income Tax Expense — 1 4 5 Operating (Loss) Income Before Equity Earnings of 50% or Less Owned Companies $ (6,851 ) $ 3,190 $ (3,495 ) $ 4,774 Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax 17 (5 ) 168 194 Net (Loss) Income from Discontinued Operations $ (6,834 ) $ 3,185 $ (3,327 ) $ 4,968

Basis of Presentation and Acc_4

Basis of Presentation and Accounting Policies - Additional Information (Details)	Nov. 01, 2019USD ($)	Nov. 01, 2019GBP (£)	Jan. 01, 2019USD ($)	Sep. 30, 2019USD ($)$ / sharesshares	Sep. 30, 2018USD ($)shares	Nov. 01, 2019GBP (£)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Basis Of Presentation And Accounting Policies [Line Items]
Operating Lease, Right-of-Use Asset				$ 18,774,000
Operating Lease, Liability				28,060,000
Impact of adoption of new accounting standard				11,026,000
Cumulative Effect on Retained Earnings, Tax				(9,840,000)	$ (20,980,000)
Contract with customer, liability				3,303,000	9,669,000		$ 1,327,000	$ 10,104,000
Capitalized interest costs, including allowance for funds used during construction, total				1,200,000
Impairment of long-lived assets held-for-use				11,700,000	$ 3,000,000
Equity method investment, other than temporary impairment				$ 1,200,000
Effective income tax rate reconciliation, percent, total				8.30%
Class of warrant or right, exercise price of warrants or rights | $ / shares				$ 0.01
Incremental common shares attributable to conversion of debt securities, total | shares				2,183,708	2,183,708
Restricted Stock
Basis Of Presentation And Accounting Policies [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount | shares				282,050	196,338
Employee Stock Option
Basis Of Presentation And Accounting Policies [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount | shares				397,119	732,191
Two Customers
Basis Of Presentation And Accounting Policies [Line Items]
Contract with customer, liability				$ 200,000
Deferred Reimbursement And Deferred Reservation Fees
Basis Of Presentation And Accounting Policies [Line Items]
Contract with customer, liability				1,200,000
Geographic Distribution, Foreign
Basis Of Presentation And Accounting Policies [Line Items]
Contract with customer, liability				$ 1,900,000
SAP | Subsequent Event | SEACAP | North Star | Discontinued Operations, Held-for-sale
Basis Of Presentation And Accounting Policies [Line Items]
Aggregate purchase price	$ 25,100,000					£ 19,500,000
Additional consideration	$ 5,200,000	£ 4,000,000
SAP | Subsequent Event | SEACAP | BPOS | North Star | Discontinued Operations, Held-for-sale
Basis Of Presentation And Accounting Policies [Line Items]
Equity interest	100.00%	100.00%
Accounting Standards Update 2016-02 [Member]
Basis Of Presentation And Accounting Policies [Line Items]
Operating Lease, Right-of-Use Asset			$ 33,700,000
Operating Lease, Liability			31,900,000
Accounting Standards Update 2016-02 [Member] | Change in Accounting Principle for Equipment, Office and Land Leases [Member]
Basis Of Presentation And Accounting Policies [Line Items]
Cumulative Effect on Retained Earnings, Net of Tax			1,700,000
Accounting Standards Update 2016-02 [Member] | Change in Accounting Principle for Unamortized Deferred Gains [Member]
Basis Of Presentation And Accounting Policies [Line Items]
Cumulative Effect on Retained Earnings, Net of Tax			8,700,000
Impact of adoption of new accounting standard			11,000,000
Cumulative Effect on Retained Earnings, Tax			$ 2,300,000

Basis of Presentation and Acc_5

Basis of Presentation and Accounting Policies - Schedule of Deferred Revenues (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Basis Of Presentation And Accounting Policies [Abstract]
Balance at beginning of period	$ 1,327	$ 10,104
Revenues deferred during the period	5,022	2,756
Revenues recognized during the period	(3,046)	(3,191)
Balance at end of period	$ 3,303	$ 9,669

Basis of Presentation and Acc_6

Basis of Presentation and Accounting Policies - Schedule of Property and Equipment Useful Life (Details)	9 Months Ended
	Sep. 30, 2019
Crew Transfer Vessels
Property Plant And Equipment [Line Items]
Estimated useful life (Year)	10 years
All Other Offshore Support Vessels
Property Plant And Equipment [Line Items]
Estimated useful life (Year)	20 years

Basis of Presentation and Acc_7

Basis of Presentation and Accounting Policies - Schedule of Deferred Gain Activity (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Basis Of Presentation And Accounting Policies [Abstract]
Balance at beginning of period	$ 11,819	$ 25,006
Amortization of deferred gains included in operating expenses as a reduction to rental expense		(6,053)
Impact of adoption of new accounting standard	(11,026)
Other adjustments	(390)	(416)
Balance at end of period	$ 403	$ 18,537

Basis of Presentation and Acc_8

Basis of Presentation and Accounting Policies - Schedule of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	$ 511,240	$ 580,815	$ 554,935	$ 523,166
Other comprehensive loss	(1,949)	(824)	(4,490)	(1,458)
Balance	494,147	564,888	494,147	564,888
Accumulated Foreign Currency Adjustment Attributable to Parent
Accumulated Other Comprehensive Income Loss [Line Items]
Balance			(15,472)
Other comprehensive loss			(1,902)
Balance	(17,374)		(17,374)
Accumulated Loss, Net, Cash Flow Hedge, Parent
Accumulated Other Comprehensive Income Loss [Line Items]
Balance			(1,316)
Other comprehensive loss			(2,415)
Balance	(3,731)		(3,731)
AOCI Attributable to Parent
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(19,156)	(13,129)	(16,788)	(12,493)
Other comprehensive loss			(4,317)
Balance	(21,105)	$ (13,945)	(21,105)	$ (13,945)
Accumulated Foreign Currency Adjustment Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income Loss [Line Items]
Balance			(1,445)
Balance	(1,445)		(1,445)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Noncontrolling Interest
Accumulated Other Comprehensive Income Loss [Line Items]
Balance			(11)
Balance	$ (11)		(11)
AOCI Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income Loss [Line Items]
Balance			0
Other comprehensive loss			$ (4,317)

Transformation, Facility Rest_3

Transformation, Facility Restructuring and Severance Charges - Additional Information (Details) - Transformation Plan - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Restructuring Cost And Reserve [Line Items]
Restructuring and related activities, description		The ongoing Transformation Plan, which began in the third quarter of 2019 and is expected to extend through the second quarter of 2020 (the “Transformation Plan”), includes a workforce reduction, organization restructure, facility consolidations and other cost reduction measures and efficiency initiative across the Company’s geographic regions. The Transformation Plan was initiated to reduce the Company’s overall cost structure and workforce to better align with current activity levels of oil and gas exploration and production.
Restructuring and transformation charges	$ 3,304	$ 3,304
Severance charges	3,056	3,056
Other restructuring charges	$ 248	$ 248

Transformation, Facility Rest_4

Transformation, Facility Restructuring and Severance Charges - Schedule of Components of Restructuring Charges By Segment (Details) - Transformation Plan - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Restructuring Cost And Reserve [Line Items]
Severance Charges	$ 3,056	$ 3,056
Other Charges	248	248
Total Charges	3,304	3,304
UNITED STATES
Restructuring Cost And Reserve [Line Items]
Severance Charges	2,937	2,937
Other Charges	247	247
Total Charges	3,184	3,184
Latin America
Restructuring Cost And Reserve [Line Items]
Other Charges	1	1
Total Charges	1	1
Europe
Restructuring Cost And Reserve [Line Items]
Severance Charges	119	119
Total Charges	$ 119	$ 119

Transformation, Facility Rest_5

Transformation, Facility Restructuring and Severance Charges - Schedule of Severance and Other Restructuring Charges (Details) - Transformation Plan $ in Thousands	3 Months Ended
	Sep. 30, 2019USD ($)
Restructuring Cost And Reserve [Line Items]
Restructuring liability	$ 564
Severance Liability
Restructuring Cost And Reserve [Line Items]
Restructuring liability	564
UNITED STATES
Restructuring Cost And Reserve [Line Items]
Restructuring liability	526
UNITED STATES | Severance Liability
Restructuring Cost And Reserve [Line Items]
Restructuring liability	526
Europe
Restructuring Cost And Reserve [Line Items]
Restructuring liability	38
Europe | Severance Liability
Restructuring Cost And Reserve [Line Items]
Restructuring liability	$ 38

Transformation, Facility Rest_6

Transformation, Facility Restructuring and Severance Charges - Schedule of Cumulative Restructuring and Reorganization Cost Incurred to Date, Estimated Remaining and to be Incurred (Details) - Transformation Plan $ in Thousands	Sep. 30, 2019USD ($)
Restructuring Cost And Reserve [Line Items]
Cumulative restructuring costs incurred to date in operating charges	$ 3,304
Estimated additional restructuring costs to be incurred	2,428
Total restructuring and reorganization costs incurred and to be incurred	$ 5,732

Equipment Acquisitions and Di_2

Equipment Acquisitions and Dispositions - Additional Information (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)Vessel
Property Plant And Equipment [Line Items]
Payments to acquire property, plant, and equipment, including fair value hedges | $	$ 49.6
Proceeds from sale of property, plant, and equipment, excluding deposits for future vessel sales | $	19.9
Proceeds from deposits | $	4.3
Gain (loss) on disposition of property, plant and equipment | $	$ 8.9
Fast Support Vessels
Property Plant And Equipment [Line Items]
Number of equipment acquired	2
Number of equipment sold	3
Crew Transfer Vessels
Property Plant And Equipment [Line Items]
Number of equipment acquired	1
Number of equipment sold	1
Platform Supply Vessels
Property Plant And Equipment [Line Items]
Number of equipment acquired	2
Vessel Under Construction
Property Plant And Equipment [Line Items]
Number of equipment sold	1
Specialty Vessel
Property Plant And Equipment [Line Items]
Number of equipment sold	1
Anchor Handling Towing Supply
Property Plant And Equipment [Line Items]
Number of equipment sold	5
Supply Vessels
Property Plant And Equipment [Line Items]
Number of equipment sold	2
Liftboats
Property Plant And Equipment [Line Items]
Number of equipment sold	3

Investments, at Equity, and A_2

Investments, at Equity, and Advances to 50% or Less Owned Companies - Additional Information (Details)	May 31, 2019USD ($)Vessel	Dec. 19, 2018USD ($)Vessel	Sep. 30, 2019USD ($)Vessel	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)Vessel
Schedule Of Investments [Line Items]
Payments to acquire interest in unconsolidated joint venture			$ 11,355,000	$ 30,253,000
FRS Windcat Offshore Logistics GmbH
Schedule Of Investments [Line Items]
Number of equipment sold | Vessel			1
Sale of vessel, consideration			$ 4,300,000
SeaCosco Offshore LLC
Schedule Of Investments [Line Items]
Contributed capital			2,000,000		$ 29,600,000
SeaCosco Offshore LLC | MOU
Schedule Of Investments [Line Items]
Agreement standstill date	Aug. 31, 2019
Loans receivable, interest rate	15.00%
Shareholder loans in respect of working capital	$ 13,000,000		8,700,000
Interest income recognized on shareholder loans in respect of working capital			$ 100,000
SeaCosco Offshore LLC | SEACOR Offshore Asia
Schedule Of Investments [Line Items]
Equity method investment, ownership percentage			50.00%
SeaCosco Offshore LLC | CSFT and CSIHK
Schedule Of Investments [Line Items]
Equity method investment, ownership percentage			50.00%
SeaCosco Offshore LLC | CSFT and CSIHK | MOU
Schedule Of Investments [Line Items]
Equity method investment, ownership percentage	50.00%
SeaCosco Offshore LLC | Platform Supply Vessels
Schedule Of Investments [Line Items]
Number of vessels delivered to the company | Vessel			4		2
Number of vessels for which the company gets title | Vessel			1		5
SeaCosco Offshore LLC | Platform Supply Vessels | MOU
Schedule Of Investments [Line Items]
Number of vessels acquired | Vessel	2
Mexmar Offshore International
Schedule Of Investments [Line Items]
Equity method investment, ownership percentage		49.00%
Payments to acquire interest in unconsolidated joint venture		$ 4,900,000
Number of vessels owned | Vessel		14
Equity investments unrealized gain loss			$ 0
Other Offshore Marine Services Joint Ventures
Schedule Of Investments [Line Items]
Equity method investment, ownership percentage			50.00%
Allocable share of uncalled capital			$ 400,000

Long Term Debt - Schedule of Lo

Long Term Debt - Schedule of Long-term Debt Obligations (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 432,674	$ 442,972
Portion due within one year	(23,446)	(16,812)
Debt discount	(27,805)	(32,005)
Issue costs	(5,651)	(6,301)
Long-term debt	375,772	387,854
SEACOR Marine Foreign Holdings Syndicated Credit Facility
Debt Instrument [Line Items]
Long-term Debt, Gross	117,000	126,750
Convertible Senior Notes
Debt Instrument [Line Items]
Long-term Debt, Gross	125,000	125,000
Falcon Global USA Term Loan Facility
Debt Instrument [Line Items]
Long-term Debt, Gross	102,349	109,099
Sea-Cat Crewzer III Term Loan Facility
Debt Instrument [Line Items]
Long-term Debt, Gross	24,128	25,989
Windcat Workboats Facilities
Debt Instrument [Line Items]
Long-term Debt, Gross	23,751	24,850
Falcon Global USA Revolver
Debt Instrument [Line Items]
Long-term Debt, Gross	15,000	15,000
SEACOR 88/888 Term Loan
Debt Instrument [Line Items]
Long-term Debt, Gross	11,000	11,000
SEACOR Alps
Debt Instrument [Line Items]
Long-term Debt, Gross	10,626
BNDES Equipment Construction Finance Notes
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 3,820	$ 5,284

Long Term Debt - Additional Inf

Long Term Debt - Additional Information (Details) - USD ($)	Sep. 30, 2019	Sep. 26, 2018
Long-term Debt Obligation
Debt Instrument [Line Items]
Letters of credit outstanding, amount	$ 3,800,000
Lease Obligation
Debt Instrument [Line Items]
Letters of credit outstanding, amount	300,000
Labor And Performance Guarantees
Debt Instrument [Line Items]
Letters of credit outstanding, amount	$ 200,000
Loan Facility With DNB Bank ASA
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 130,000,000
SEACOR Alps
Debt Instrument [Line Items]
Debt instrument, percentage of financing on total purchase price	70.00%
Debt instrument, interest rate	5.00%
Debt instrument, maturity period	2023

Leases - Additional Information

Leases - Additional Information (Details)	9 Months Ended
	Sep. 30, 2019Vessel
Anchor Handling Towing Supply Vessels
Lessee Lease Description [Line Items]
Number of operating leases on equipment	4
Liftboats
Lessee Lease Description [Line Items]
Number of operating leases on equipment	2
Fast Support Vessels
Lessee Lease Description [Line Items]
Number of operating leases on equipment	1
Supply Vessels, Certain Facilities And Other Equipments
Lessee Lease Description [Line Items]
Number of operating leases on equipment	1
Vessels | Minimum
Lessee Lease Description [Line Items]
Operating lease, lease terms (in duration)	2 months
Vessels | Maximum
Lessee Lease Description [Line Items]
Operating lease, lease terms (in duration)	26 months
Other Equipment | Minimum
Lessee Lease Description [Line Items]
Operating lease, lease terms (in duration)	4 months
Other Equipment | Maximum
Lessee Lease Description [Line Items]
Operating lease, lease terms (in duration)	327 months

Leases - Summary of Future Mini

Leases - Summary of Future Minimum Payments For Operating Leases (Details) $ in Thousands	Sep. 30, 2019USD ($)
Leases [Abstract]
Remainder of 2019	$ 4,897
2020	14,066
2021	7,120
2022	663
2023	622
Years subsequent to 2023	4,851
Operating lease payments due	32,219
Interest component	(4,159)
Total operating leases	28,060
Current portion of long-term operating lease liabilities	15,182
Long-term operating lease liabilities	$ 12,878

Leases - Summary of Components

Leases - Summary of Components of Leases Expense (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease expense	$ 3,446	$ 10,669
Short-term lease expense (lease duration of twelve months or less at lease commencement)	725	1,967
Total Lease expense	$ 4,171	$ 12,636

Leases - Summary of Other Infor

Leases - Summary of Other Information Related to Operating Leases (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Leases [Abstract]
Operating cash flows from operating leases	$ 14,671
Right-of-use assets obtained for operating lease liabilities	$ 33,979
Weighted average remaining lease term, in years	4 years 10 months 24 days
Weighted average discount rate	4.20%

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details)	9 Months Ended
	Sep. 30, 2019
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory rate	21.00%
Foreign taxes not creditable against U.S. income tax	(5.40%)
Foreign earnings not subject to U.S. income tax	(3.60%)
Return to provision	(3.60%)
Noncontrolling interests	(1.90%)
State taxes	1.60%
Other	0.20%
Effective income tax rate reconciliation, percent, total	8.30%

Derivative Instruments and He_3

Derivative Instruments and Hedging Strategies - Schedule of Fair Value of Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Designated as Hedging Instrument | Cash Flow Hedging
Derivative [Line Items]
Derivative Liability	$ 3,576	$ 1,659
Designated as Hedging Instrument | Interest Rate Swap | Cash Flow Hedging
Derivative [Line Items]
Derivative Liability	3,576	1,659
Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Liability	8,119	6,935
Conversion option liability on Convertible Senior Notes	$ 4,543	$ 5,276

Derivative Instruments and He_4

Derivative Instruments and Hedging Strategies - Additional Information (Details) € in Millions, $ in Millions	Sep. 30, 2019USD ($)	Sep. 30, 2019EUR (€)	Sep. 30, 2018
Maximum
Derivative [Line Items]
Equity method investment, ownership percentage	50.00%	50.00%	50.00%
Interest Rate Swap | OSV Partners
Derivative [Line Items]
Derivative, number of instruments held, total	2	2
Derivative, notional amount	$ 24.1
Interest Rate Swap | OSV Partners | Minimum
Derivative [Line Items]
Derivative, fixed interest rate	1.89%	1.89%
Interest Rate Swap | OSV Partners | Maximum
Derivative [Line Items]
Derivative, fixed interest rate	2.27%	2.27%
Cash Flow Hedging | Interest Rate Swap | Designated as Hedging Instrument | Windcat Workboats Holdings Ltd
Derivative [Line Items]
Derivative, number of instruments held, total	2	2
Derivative, fixed interest rate	0.03%	0.03%
Derivative, notional amount	$ 16.4	€ 15
Cash Flow Hedging | Interest Rate Swap | Designated as Hedging Instrument | SEACOR 88/888
Derivative [Line Items]
Derivative, fixed interest rate	3.20%	3.20%
Derivative, notional amount	$ 5.5
Cash Flow Hedging | Interest Rate Swap | Designated as Hedging Instrument | MexMar
Derivative [Line Items]
Derivative, number of instruments held, total	5	5
Derivative, notional amount	$ 87.5
Equity method investment, ownership percentage	49.00%	49.00%
Cash Flow Hedging | Interest Rate Swap | Designated as Hedging Instrument | MexMar | Minimum
Derivative [Line Items]
Derivative, fixed interest rate	1.71%	1.71%
Cash Flow Hedging | Interest Rate Swap | Designated as Hedging Instrument | MexMar | Maximum
Derivative [Line Items]
Derivative, fixed interest rate	2.10%	2.10%
Cash Flow Hedging | 3.32% Interest Rate Swap Agreement | Designated as Hedging Instrument | SMFH
Derivative [Line Items]
Derivative, fixed interest rate	3.32%	3.32%
Derivative, notional amount	$ 9
Cash Flow Hedging | 3.195% Interest Rate Swap Agreement | Designated as Hedging Instrument | SMFH
Derivative [Line Items]
Derivative, fixed interest rate	3.195%	3.195%
Derivative, notional amount	$ 50

Derivative Instruments and He_5

Derivative Instruments and Hedging Strategies - Schedule of (Losses) Gains on Derivative Instruments not Designated as Hedging Instruments (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Derivative [Line Items]
Gains (losses) on derivative instruments	$ 734	$ (9,797)
Embedded Derivative Financial Instruments
Derivative [Line Items]
Gains (losses) on derivative instruments	$ 734	(11,096)
Interest Rate Swap
Derivative [Line Items]
Gains (losses) on derivative instruments		$ 1,299

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Inputs, Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Construction reserve funds	$ 18,161	$ 28,221
Fair Value, Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Liability	3,576	1,659
Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Conversion Option Liability on Convertible Senior Notes	$ 4,543	$ 5,276

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Estimated Fair Values of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Reported Value Measurement
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	$ 42,171	$ 93,254
Investments, at cost, in 50% or less owned companies (included in other assets)	132	132
Long-term debt, including current portion	399,219	404,666
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	42,171	93,254
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, including current portion	$ 382,367	$ 388,949

Fair Value Measurements - Sch_3

Fair Value Measurements - Schedule of Other Assets and Liabilities Measured at Fair Value (Details) - Fair Value, Inputs, Level 2 $ in Thousands	Sep. 30, 2019USD ($)
Anchor Handling Towing Supply
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Property and equipment	$ 1,210
Fast Support Vessels
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Property and equipment	$ 2,490

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Fair Value Disclosures [Abstract]
impairment charges	$ 11.7

Warrants - Additional Informati

Warrants - Additional Information (Details) - USD ($)	Jun. 14, 2019	May 28, 2019	Jun. 08, 2018	May 31, 2018	May 02, 2018	Apr. 26, 2018	Sep. 30, 2019	Sep. 30, 2018
Class Of Warrant Or Right [Line Items]
Stock issued during period, value, new issues							$ 6,596,000	$ 42,995,000
Class of warrant or right, exercise price of warrants or rights							$ 0.01
Carlyle Group | Convertible Senior Notes Converted to Warrants
Class Of Warrant Or Right [Line Items]
Class of warrant or right, exercise price of warrants or rights					$ 0.01
Debt conversion, original debt, amount					$ 50,000,000
Warrants Issued in Private Placement
Class Of Warrant Or Right [Line Items]
Class of warrant or right, outstanding						2,168,586
Class of warrant or right, number of securities called by warrants or rights						674,164
Class of warrant or right, exercise price of warrants or rights						$ 0.01
PIPE Warrants
Class Of Warrant Or Right [Line Items]
Class of warrant or right, exercise price of warrants or rights						$ 0.01
Warrants and rights outstanding, term						25 years
Exchange Warrants
Class Of Warrant Or Right [Line Items]
Class of warrant or right, outstanding							1,826,966
Class of warrant or right, exercise price of warrants or rights					$ 0.01
Warrants and rights outstanding, term					25 years
Class of warrant or right, exercised during period	64,440	380,000	38,857	250,693
Class of warrant or right, exercised during period, exercise price			$ 0.01	$ 0.01
Common stock withheld	49
Exchange Warrants | Carlyle Group
Class Of Warrant Or Right [Line Items]
Class of warrant or right, number of securities called by warrants or rights					1,886,292
Private Placement
Class Of Warrant Or Right [Line Items]
Stock issued during period, value, new issues						$ 56,855,000

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) $ in Thousands, € in Millions, £ in Millions	Mar. 15, 2019USD ($)shares	Mar. 15, 2019EUR (€)shares	Jan. 25, 2019USD ($)	Jan. 25, 2019GBP (£)	Jan. 09, 2019USD ($)Vesselshares	Sep. 30, 2019USD ($)	Jan. 01, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Cumulative Effect of New Accounting Principle in Period of Adoption								$ 10,416	$ (12,069)
Common stock value						$ 219		204
Windcat Workboats Facilities | Seabulk Overseas
Business acquisition, percentage of voting interests acquired	6.25%	6.25%	6.25%	6.25%		100.00%
Business combination, consideration transferred, total	$ 1,400	€ 1.2	$ 2,000	£ 1.5
Business acquisition, exchange for consideration | shares	50,000	50,000
Private Placement
Stock Issued During Period, Shares, New Issues | shares					603,872
Number of equipment acquired | Vessel					3
Common stock value					$ 7,800
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption								$ 10,416	$ (12,069)
Retained Earnings [Member] | Accounting Standards Update 2016-02 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption							$ 10,400

Noncontrolling Interests in S_3

Noncontrolling Interests in Subsidiaries - Schedule of Noncontrolling Interests in the Company's Consolidated Subsidiaries (Details) - USD ($) $ in Thousands	Sep. 30, 2019		Dec. 31, 2018
Minority Interest [Line Items]
Noncontrolling interest	$ 22,895		$ 29,404
Falcon Global
Minority Interest [Line Items]
Noncontrolling interest, percent	28.00%
Noncontrolling interest	$ 22,580		$ 26,989
Windcat Workboats Facilities
Minority Interest [Line Items]
Noncontrolling interest, percent	0.00%	[1]	12.50%
Noncontrolling interest			$ 2,115
Other Noncontrolling Interests
Minority Interest [Line Items]
Noncontrolling interest, percent	1.80%
Noncontrolling interest	$ 315		$ 300
[1]	As of September 30, 2019; at December 31, 2018, noncontrolling interest was 12.5%.

Noncontrolling Interests in S_4

Noncontrolling Interests in Subsidiaries - Schedule of Noncontrolling Interests in the Company's Consolidated Subsidiaries (Details) (Parenthetical)	Sep. 30, 2019		Dec. 31, 2018
Windcat Workboats Facilities
Minority Interest [Line Items]
Noncontrolling interest, percent	0.00%	[1]	12.50%
[1]	As of September 30, 2019; at December 31, 2018, noncontrolling interest was 12.5%.

Noncontrolling Interests in S_5

Noncontrolling Interests in Subsidiaries - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Mar. 15, 2019	Jan. 25, 2019
Minority Interest [Line Items]
Net income (loss), including portion attributable to noncontrolling interest, total	$ (18,241)	$ (15,766)	$ (76,778)	$ (74,083)
Net income (loss) attributable to noncontrolling interest, total	$ 204	$ 191	(4,395)	(4,269)
Windcat Workboats Facilities
Minority Interest [Line Items]
Net income (loss), including portion attributable to noncontrolling interest, total			2,000
Net income (loss) attributable to noncontrolling interest, total			200
Falcon Global Holdings
Minority Interest [Line Items]
Net income (loss), including portion attributable to noncontrolling interest, total			30,100	14,200
Net income (loss) attributable to noncontrolling interest, total			$ 8,400	$ 4,000
Noncontrolling interest, ownership percentage by parent	72.00%		72.00%
Windcat Workboats
Minority Interest [Line Items]
Noncontrolling interest, ownership percentage by parent						87.00%
Windcat Workboats | Seabulk Overseas
Minority Interest [Line Items]
Business acquisition, percentage of voting interests acquired					6.25%	6.25%

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) € in Millions, R$ in Millions	Feb. 08, 2018USD ($)	Feb. 28, 2015USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2019EUR (€)	Sep. 30, 2019BRL (R$)
Commitments And Contingencies [Line Items]
Remaining capital commitment			$ 71,900,000
Unrecorded unconditional purchase obligation, due in remainder of fiscal year			17,700,000
Unrecorded unconditional purchase obligation, due within two years			23,800,000
Unrecorded unconditional purchase obligation, due within three years			30,400,000
Amount guaranteed under arrangement			$ 27,000,000
Deposited with Court		$ 1,200,000
PIS
Commitments And Contingencies [Line Items]
Cost allocation percentage			70.00%
COFINS
Commitments And Contingencies [Line Items]
Cost allocation percentage			30.00%
Minimum
Commitments And Contingencies [Line Items]
Potential range of levies			$ 3,200,000		R$ 12.8
Maximum
Commitments And Contingencies [Line Items]
Potential range of levies			$ 4,400,000		R$ 17.5
FGUSA Credit Facility [Member]
Commitments And Contingencies [Line Items]
Debt Agreement, Maximum Borrowing Capacity	$ 131,100,000
Debt instrument maturity date	Feb. 8, 2020
FGUSA Credit Facility [Member] | Revolving Credit Facility [Member]
Commitments And Contingencies [Line Items]
Line of credit facility, maximum borrowing capacity	$ 15,000,000
Debt Instrument, Interest Rate, Effective Percentage	6.3125%
SEACOR Holdings
Commitments And Contingencies [Line Items]
Related party transaction, rate			0.50%
Line of Credit | Performance Guarantee
Commitments And Contingencies [Line Items]
Amount guaranteed under arrangement | €				€ 0.9
Term Loan [Member] | FGUSA Credit Facility [Member]
Commitments And Contingencies [Line Items]
Long-term Debt, Total	$ 116,100,000
Crew Transfer Vessels
Commitments And Contingencies [Line Items]
Unrecorded unconditional purchase obligation, maximum quantity			2	2	2
Platform Supply Vessels
Commitments And Contingencies [Line Items]
Unrecorded unconditional purchase obligation, maximum quantity			3	3	3

Stock Based Compensation - Summ

Stock Based Compensation - Summary of Transactions in Connection with 2017 Equity Incentive Plan (Details)	9 Months Ended
	Sep. 30, 2019shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding as of December 31, 2018 (in shares)	805,566
Granted (in shares)	189,878
Exercise of options (in shares)	86,494
Forfeited (in shares)	5,000
Outstanding as of September 30, 2019 (in shares)	903,950
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding as of December 31, 2018 (in shares)	192,346
Granted (in shares)	321,100
Vested (in shares)	116,796
Forfeited (in shares)	1,000
Outstanding as of September 30, 2019 (in shares)	395,650

Stock Based Compensation - Addi

Stock Based Compensation - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Treasury stock, shares acquired			38,448
Treasury stock, value acquired cost method	$ 240	$ 32	$ 524	$ 83

Segment Information - Schedule

Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2019		Sep. 30, 2018		Sep. 30, 2019		Sep. 30, 2018		Dec. 31, 2018
Segment Reporting Information [Line Items]
Operating Revenues	$ 54,700		$ 58,169		$ 152,422		$ 144,670
Direct Costs and Expenses	27,211		38,400		97,747		99,839
Direct Vessel Profit, from Continuing Operations	27,489		19,769		54,675		44,831
Lease expense	4,171		3,292		12,636		9,881
Administrative and general	12,509		11,767		36,148		39,182
Depreciation and amortization	16,091		16,397		48,600		52,940
Other Costs and Expenses	32,771		31,456		97,384		102,003
Gain on Asset Dispositions and Impairments	861		(1,765)		(2,719)		(3,493)
Operating Loss, for Continuing Operations	(4,421)		(13,452)		(45,428)		(60,665)
Historical cost	1,070,374		1,148,842		1,070,374		1,148,842		$ 1,116,583
Accumulated depreciation	(400,628)		(466,419)		(400,628)		(466,419)		(461,399)
Property and equipment	669,746		682,423		669,746		682,423		$ 655,184
Total Assets	894,554	[1]	929,267	[2]	894,554	[1]	929,267	[2]
Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	49,747		50,866		137,836		128,992
Bareboat Charter
Segment Reporting Information [Line Items]
Operating Revenues	1,765		1,168		4,297		3,467
Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	3,188		6,135		10,289		12,211
Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	15,879		19,166		50,416		50,489
Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	5,495		7,581		20,686		20,706
Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	515		3,666		5,082		6,670
Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	1,198		1,623		4,375		4,466
Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	2,910		3,715		8,918		9,548
Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	1,214		2,649		8,270		7,960
UNITED STATES
Segment Reporting Information [Line Items]
Operating Revenues	12,349		15,522		35,667		33,887
Direct Costs and Expenses	7,606		8,915		29,826		23,984
Direct Vessel Profit, from Continuing Operations	4,743		6,607		5,841		9,903
Lease expense	2,758		2,078		8,611		6,187
Depreciation and amortization	5,634		5,227		16,473		17,677
Historical cost	329,913		479,303		329,913		479,303
Accumulated depreciation	(161,315)		(242,364)		(161,315)		(242,364)
Property and equipment	168,598		236,939		168,598		236,939
Total Assets	251,547	[1]	377,798	[2]	251,547	[1]	377,798	[2]
UNITED STATES | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	10,914		12,800		31,547		27,834
UNITED STATES | Bareboat Charter
Segment Reporting Information [Line Items]
Operating Revenues	597				830
UNITED STATES | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	838		2,722		3,290		6,053
UNITED STATES | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	4,353		4,853		14,059		13,481
UNITED STATES | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	1,508		1,801		6,801		4,024
UNITED STATES | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	547		375		4,342		1,810
UNITED STATES | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	371		612		1,804		1,948
UNITED STATES | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	739		1,120		2,529		2,513
UNITED STATES | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	88		154		291		208
Africa
Segment Reporting Information [Line Items]
Operating Revenues	11,867		12,978		33,156		36,531
Direct Costs and Expenses	6,268		10,632		21,013		27,423
Direct Vessel Profit, from Continuing Operations	5,599		2,346		12,143		9,108
Lease expense	761		1,061		2,333		3,222
Depreciation and amortization	2,681		2,381		7,796		8,112
Historical cost	221,080		186,729		221,080		186,729
Accumulated depreciation	(64,748)		(53,498)		(64,748)		(53,498)
Property and equipment	156,332		133,231		156,332		133,231
Total Assets	167,714	[1]	144,325	[2]	167,714	[1]	144,325	[2]
Africa | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	11,738		11,201		32,911		33,117
Africa | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	129		1,777		245		3,414
Africa | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	3,308		4,486		10,603		12,873
Africa | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	1,323		2,438		3,459		5,457
Africa | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	(53)		1,201		237		2,113
Africa | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	230		323		682		789
Africa | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	961		1,081		2,654		2,650
Africa | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	499		1,103		3,378		3,541
Middle East and Asia [Member]
Segment Reporting Information [Line Items]
Operating Revenues	15,212		12,507		41,463		36,550
Direct Costs and Expenses	7,031		9,033		24,868		27,786
Direct Vessel Profit, from Continuing Operations	8,181		3,474		16,595		8,764
Lease expense	43		57		131		175
Depreciation and amortization	3,914		4,207		12,437		14,608
Historical cost	297,735		310,110		297,735		310,110
Accumulated depreciation	(74,225)		(81,121)		(74,225)		(81,121)
Property and equipment	223,510		228,989		223,510		228,989
Total Assets	257,294	[1]	261,531	[2]	257,294	[1]	261,531	[2]
Middle East and Asia [Member] | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	14,798		12,590		40,472		37,555
Middle East and Asia [Member] | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	414		(83)		991		(1,005)
Middle East and Asia [Member] | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	4,023		4,361		12,569		12,452
Middle East and Asia [Member] | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	1,387		2,091		6,209		8,095
Middle East and Asia [Member] | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	20		352		454		413
Middle East and Asia [Member] | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	333		385		1,041		982
Middle East and Asia [Member] | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	701		892		2,135		2,848
Middle East and Asia [Member] | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	567		952		2,460		2,996
Latin America
Segment Reporting Information [Line Items]
Operating Revenues	3,340		9,063		13,515		18,247
Direct Costs and Expenses	1,275		3,017		6,694		6,158
Direct Vessel Profit, from Continuing Operations	2,065		6,046		6,821		12,089
Lease expense			1		1		4
Depreciation and amortization	1,573		2,521		5,168		6,020
Historical cost	108,224		102,776		108,224		102,776
Accumulated depreciation	(50,928)		(47,374)		(50,928)		(47,374)
Property and equipment	57,296		55,402		57,296		55,402
Total Assets	125,138	[1]	125,720	[2]	125,138	[1]	125,720	[2]
Latin America | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	1,951		7,479		8,919		13,409
Latin America | Bareboat Charter
Segment Reporting Information [Line Items]
Operating Revenues	1,168		1,168		3,467		3,467
Latin America | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	221		416		1,129		1,371
Latin America | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	846		1,662		3,378		3,257
Latin America | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	298		312		1,114		649
Latin America | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses			103		47		114
Latin America | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	31		163		232		399
Latin America | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	187		427		929		841
Latin America | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	(87)		350		994		898
Europe | Continuing Operations
Segment Reporting Information [Line Items]
Operating Revenues	11,932		8,099		28,621		19,455
Direct Costs and Expenses	5,031		6,803		15,346		14,488
Direct Vessel Profit, from Continuing Operations	6,901		1,296		13,275		4,967
Lease expense	609		95		1,560		293
Depreciation and amortization	2,289		2,061		6,726		6,523
Historical cost	113,422		69,924		113,422		69,924
Accumulated depreciation	(49,412)		(42,062)		(49,412)		(42,062)
Property and equipment	64,010		27,862		64,010		27,862
Total Assets	92,861	[1]	19,893	[2]	92,861	[1]	19,893	[2]
Europe | Continuing Operations | Time Charter
Segment Reporting Information [Line Items]
Operating Revenues	10,346		6,796		23,987		17,077
Europe | Continuing Operations | Other Marine Services
Segment Reporting Information [Line Items]
Operating Revenues	1,586		1,303		4,634		2,378
Europe | Continuing Operations | Personnel
Segment Reporting Information [Line Items]
Direct Costs and Expenses	3,349		3,804		9,807		8,426
Europe | Continuing Operations | Repairs and Maintenance
Segment Reporting Information [Line Items]
Direct Costs and Expenses	979		939		3,103		2,481
Europe | Continuing Operations | Drydocking
Segment Reporting Information [Line Items]
Direct Costs and Expenses	1		1,635		2		2,220
Europe | Continuing Operations | Insurance and Loss Reserves
Segment Reporting Information [Line Items]
Direct Costs and Expenses	233		140		616		348
Europe | Continuing Operations | Fuel, Lubes and Supplies
Segment Reporting Information [Line Items]
Direct Costs and Expenses	322		195		671		696
Europe | Continuing Operations | Other Direct Costs and Expenses
Segment Reporting Information [Line Items]
Direct Costs and Expenses	$ 147		$ 90		$ 1,147		$ 317
[1]	Total assets by region does not include corporate assets of $145,952 as of September 30, 2019.
[2]	Total assets by region does not include corporate assets of $226,210 as of September 30, 2018.

Segment Information - Schedul_2

Segment Information - Schedule of Segment Reporting Information, by Segment (Parenthetical) (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Segment Reporting Information [Line Items]
Assets, Total	$ 1,040,506,000	$ 1,102,938,000
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Assets, Total	$ 145,952		$ 226,210

Segment Information - Additiona

Segment Information - Additional Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Segment Information [Line Items]
Equity method investments	$ 107.3
Equity in (Losses) Earnings of 50% or Less Owned Companies	$ (11.9)	$ (1.7)
Maximum
Segment Information [Line Items]
Equity method investment, ownership percentage	50.00%	50.00%
Other Offshore Marine Services Joint Ventures
Segment Information [Line Items]
Equity method investment, ownership percentage	50.00%
Equity method investments		$ 118.5
Other Offshore Marine Services Joint Ventures | Maximum
Segment Information [Line Items]
Equity method investment, ownership percentage		50.00%

Assets Held for Sale - Schedule

Assets Held for Sale - Schedule of Assets Held for Sale (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Assets from Discontinued Operations:
Current assets	$ 13,127		$ 13,127		$ 15,222
Total current liabilities	3,813		3,813		2,526
Other Income (Expense)
Net (Loss) Income from Discontinued Operations	(6,834)	$ 3,185	(3,327)	$ 4,968
BPOS | Discontinued Operations, Held-for-sale
Assets from Discontinued Operations:
Current assets	13,130		13,130		15,225
Net property and equipment	16,262		16,262		26,277
Assets from discontinued operations	29,392		29,392		41,502
Total current liabilities	3,813		3,813		$ 2,526
Operating Revenues:
Operating Revenues	11,212	12,086	34,084	38,007
Costs and Expenses:
Operating	9,847	10,198	27,113	33,087
Depreciation	1,035	945	3,213	2,320
Direct Vessel Profit	1,365	1,888	6,971	4,920
(Loss) Gain on Asset Dispositions and Impairments, Net	(7,084)	2,351	(6,993)	2,491
Operating (Loss) Income	(6,754)	3,294	(3,235)	5,091
Other Income (Expense)
Interest income		4	10	8
Interest expense	(55)	(101)	(184)	(306)
Foreign currency translation loss	(42)	(6)	(82)	(14)
Other Income (Expense)	(97)	(103)	(256)	(312)
Operating (Loss) Income Before Equity Earnings of 50% or Less Owned Companies, Net of Tax	(6,851)	3,191	(3,491)	4,779
Income Tax Expense		1	4	5
Operating (Loss) Income Before Equity Earnings of 50% or Less Owned Companies	(6,851)	3,190	(3,495)	4,774
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	17	(5)	168	194
Net (Loss) Income from Discontinued Operations	(6,834)	3,185	(3,327)	4,968
BPOS | Discontinued Operations, Held-for-sale | Time Charter
Operating Revenues:
Operating Revenues	11,223	12,036	34,034	37,878
BPOS | Discontinued Operations, Held-for-sale | Other Revenue
Operating Revenues:
Operating Revenues	$ (11)	$ 50	$ 50	$ 129

Assets Held for sale- Additiona

Assets Held for sale- Additional Information (Details) - ERRV - Discontinued Operations, Held-for-sale - USD ($) $ in Millions	Nov. 01, 2019	Sep. 30, 2019
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Loss on sale of business		$ 7.1
SAP | Subsequent Event
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Loss on sale of business	$ 5.6
Reduction in loss on sale of business	$ 1.5