Class of warrant or right, exercise price description.

No definition available.

Name:	omex_ClassOfWarrantOrRightExercisePriceDescription
Namespace Prefix:	omex_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument, convertible, conversion price upon default

+ References

No definition available.

+ Details

Name:	omex_DebtInstrumentConvertibleConversionPriceUponDefault
Namespace Prefix:	omex_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt instrument, installment amount.

+ References

No definition available.

+ Details

Name:	omex_DebtInstrumentInstallmentAmount
Namespace Prefix:	omex_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value of warrants issued in connection with convertible debt.

+ References

No definition available.

+ Details

Name:	omex_FairValueOfWarrantsIssuedInConnectionWithConvertibleDebt
Namespace Prefix:	omex_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Judgment amount for acceleration of indebtedness.

+ References

No definition available.

+ Details

Name:	omex_JudgmentAmountForAccelerationOfIndebtedness
Namespace Prefix:	omex_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Pledged units of ownership.

+ References

No definition available.

+ Details

Name:	omex_PledgedUnitsOfOwnership
Namespace Prefix:	omex_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Warrant expiration date.

+ References

No definition available.

+ Details

Name:	omex_WarrantExpirationDate
Namespace Prefix:	omex_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(2))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of new shares issued in the conversion of stock in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4313-108586

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

+ Details

Name:	us-gaap_ConversionOfStockSharesIssued1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

+ Details

Name:	us-gaap_DebtConversionOriginalDebtAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Discussion of whether the debt instrument is secured or unsecured, and, if secured, a description of the collateral and guarantees required or provided.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

Name:	us-gaap_DebtInstrumentCollateral
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of a favorable spread to a debt holder between the amount of debt being converted and the value of the securities received upon conversion. This is an embedded conversion feature of convertible debt issued that is in-the-money at the commitment date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21538-112644

+ Details

Name:	us-gaap_DebtInstrumentConvertibleBeneficialConversionFeature
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870

+ Details

Name:	us-gaap_DebtInstrumentConvertibleCarryingAmountOfTheEquityComponent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031898-161870

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionPrice1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instrument must exceed threshold percentage for specified number of trading days to trigger conversion feature.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Increase for accrued, but unpaid interest on the debt instrument for the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_DebtInstrumentIncreaseAccruedInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of a subjective acceleration clause that is a part of the debt instrument. A subjective acceleration clause is a provision in a debt agreement that states that the creditor may accelerate the scheduled maturities of the obligation under conditions that are not objectively determinable (for example, if the debtor fails to maintain satisfactory operations or if a material adverse change occurs).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=99376301&loc=d3e1002-112600

+ Details

Name:	us-gaap_DebtInstrumentSubjectiveAccelerationClause
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399

+ Details

Name:	us-gaap_DeferredFinanceCostsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Consideration given by issuer of convertible debt to provide an incentive for debt holders to convert the debt to equity securities. The expense is equal to the fair value of all securities and other consideration transferred in the transaction in excess of the fair value of securities issuable pursuant to the original conversion terms.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 40
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=99385385&loc=d3e6835-112609

+ Details

Name:	us-gaap_InducedConversionOfConvertibleDebtExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6036836-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227

+ Details

Name:	us-gaap_InterestExpenseDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=omex_EpsilonAcquisitionsLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_NotesPayableOtherPayablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=omex_TrancheThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=omex_TrancheFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=omex_TrancheFiveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=omex_MinosaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=omex_TrancheMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Loans Payable - Note 4 - Epsilon - Additional Information (Detail) $ / shares in Units, Cuota in Millions								3 Months Ended			9 Months Ended	12 Months Ended
	Aug. 10, 2017 USD ($)	Mar. 21, 2017 USD ($) shares	Dec. 15, 2016 $ / shares shares	Nov. 15, 2016 $ / shares shares	Oct. 16, 2016 $ / shares shares	Oct. 01, 2016 USD ($) d $ / shares shares	Mar. 18, 2016 USD ($) d Cuota $ / shares	Sep. 30, 2018 USD ($) $ / shares	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($) shares	Sep. 30, 2018 USD ($) Cuota $ / shares shares	Dec. 31, 2017 USD ($)	Mar. 18, 2017 USD ($)
Debt Instrument [Line Items]
Warrant right exercise price \| $ / shares								$ 3.52			$ 3.52
Epsilon Acquisitions, LLC [Member]
Debt Instrument [Line Items]
Aggregate amount issuable							$ 6,000,000
Aggregate fair value of warrants								$ 303,712
Inducement expense								303,712
Debt, interest expense								25,205	$ 47,123
Notes Payable, Other Payables [Member] \| Third Tranche [Member]
Debt Instrument [Line Items]
Conversion price of Notes \| $ / shares					$ 3.52
Conversion of stock, shares Issued \| shares					1,000,000
Notes Payable, Other Payables [Member] \| Fourth Tranche [Member]
Debt Instrument [Line Items]
Conversion price of Notes \| $ / shares				$ 4.19
Conversion of stock, shares Issued \| shares				1,000,000
Notes Payable, Other Payables [Member] \| Fifth Tranche [Member]
Debt Instrument [Line Items]
Conversion price of Notes \| $ / shares			$ 4.13
Conversion of stock, shares Issued \| shares			1,000,000
Notes Payable, Other Payables [Member] \| MINOSA [Member]
Debt Instrument [Line Items]
Aggregate amount issuable							14,750,000
Debt Instrument, acceleration clause description											The indebtedness may be accelerated upon the occurrence of specified events of default including (a) OME’s failure to pay any amount payable on the date due and payable; (b) OME or we fail to perform or observe any term, covenant, or agreement in the Purchase Agreement or the related documents, subject to a five-day cure period; (c) an event of default or material breach by OME, us or any of our affiliates under any of the other loan documents shall have occurred and all grace periods, if any, applicable thereto shall have expired; (d) the Stock Purchase Agreement shall have been terminated; (e) specified dissolution, liquidation, insolvency, bankruptcy, reorganization, or similar cases or actions are commenced by or against OME or any of its subsidiaries, in specified circumstances unless dismissed or stayed within 60 days; (f) the entry of judgment or award against OME or any of its subsidiaries in excess or $100,000; and (g) a change in control (as defined in the Purchase Agreement) occurs
Judgment amount for acceleration of indebtedness							100,000
Notes Payable, Other Payables [Member] \| Epsilon Acquisitions, LLC [Member]
Debt Instrument [Line Items]
Aggregate amount issuable		$ 6,000,000				$ 3,000,000	3,000,000						$ 3,000,000
Installment amount of Notes							$ 1,500,000
Interest rate, stated percentage						10.00%	10.00%
Notes security description											We granted security interests to Epsilon in (a) the 54 million cuotas (a unit of ownership under Panamanian law) of Oceanica Resources S. de R.L. (“Oceanica”) held by our wholly owned subsidiary, Odyssey Marine Enterprises, Ltd. (“OME”), (b) all notes and other receivables from Oceanica and its subsidiary owed to the Odyssey Pledgors, and (c) all of the outstanding equity in OME.
Conversion price of Notes \| $ / shares						$ 5.00	$ 5.00
Conversion price of Notes upon default \| $ / shares							$ 2.50
Debt instrument maturity date						Mar. 18, 2017	Mar. 18, 2017
Pledged units of ownership \| Cuota							54				54
Number of trading days \| d						75	75
Lender's out of pocket costs								50,000			$ 50,000
Accrued interest										$ 302,274
Conversion of stock, shares Issued \| shares		670,455								670,455	670,455
Beneficial conversion feature recorded											$ 96,000
Debt conversion amount	$ 2,000,000											$ 2,000,000
Common stock purchase warrant \| shares						120,000
Warrant right exercise price \| $ / shares						$ 3.52
Warrant Expiration Date											Oct. 01, 2021
Warrant right exercise price description											Warrant shall be the number determined by multiplying 120,000 by a fraction, (a) the numerator of which is the aggregate principal amount of advances that have been extended to the OME by Epsilon pursuant to the Restated Note Purchase Agreement on or after the date of the Warrant and prior to the date of such failure and (b) the denominator of which is $3.0 million.
Equity component in loans payable		$ 3,000,000						3,000,000			$ 3,000,000
Amount of loan outstanding		2,000,000						$ 1,000,000			1,000,000
Notes Payable, Other Payables [Member] \| Epsilon Acquisitions, LLC [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Aggregate amount issuable		$ 6,050,000
Notes Payable, Other Payables [Member] \| Epsilon Acquisitions, LLC [Member] \| Maximum [Member] \| Tranche [Member]
Debt Instrument [Line Items]
Accrued interest											$ 302,274
Conversion of stock, shares Issued \| shares						1,388,769