XML 54 R42.htm IDEA: XBRL DOCUMENT
v3.21.2

Investments In Unconsolidated Entities - Additional Information (Detail) - USD ($) | 3 Months Ended | 6 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Mar. 31, 2017 | Jun. 30, 2021 | Dec. 31, 2012 | Dec. 31, 2020
Schedule of Equity Method Investments [Line Items] |  |  |  |
Investment carrying value |  | $ 2,809,450 |  | $ 2,370,794
Greg Stemm [Member] |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Investment carrying value |  | 2,809,450 |  | $ 2,370,794
Chatham Rock Phosphate, Ltd. [Member] |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Investment carrying value |  | $ 0 |  |
Deep sea mining exploratory services |  |  | $ 1,680,000 |
Shares received from CRP | 141,884 |  | 9,320,348 |
Outstanding equity stake in CRP | 1.00% |  |  |
Neptune Minerals, Inc. [Member] |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Ownership percentage |  | 14.00% |  |
Investment carrying value |  | $ 0 |  |
Neptune Minerals, Inc. [Member] | Common Class A [Member] |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Investment carrying value |  | $ 0 |  |
Neptune Minerals, Inc. [Member] | Common Class B Non Voting Shares [Member] |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Current investment position in NMI |  | 3,092,488 |  |
Aggregate number of shares converted |  | 261,200 |  |
Neptune Minerals, Inc. [Member] | Series A Preferred Non Voting Shares [Member] |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Current investment position in NMI |  | 2,612 |  |
Dorado Ocean Resources, Ltd. [Member] |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Loss from unconsolidated entity |  | $ 21,300,000 |  |

X
- Definition Cumulative and outstanding losses. + References No definition available. + Details
Name: | omex_CumulativeAndOutstandingLosses
Namespace Prefix: | omex_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Equity method investments number of shares owned. + References No definition available. + Details
Name: | omex_EquityMethodInvestmentsNumberOfSharesOwned
Namespace Prefix: | omex_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Mining exploratory service revenue. + References No definition available. + Details
Name: | omex_MiningExploratoryServiceRevenue
Namespace Prefix: | omex_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Shares received from unconsolidated entities. + References No definition available. + Details
Name: | omex_SharesReceivedFromUnconsolidatedEntities
Namespace Prefix: | omex_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of shares converted 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 4 -URI http://asc.fasb.org/extlink&oid=121583591&loc=d3e4313-108586 Reference 2: 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=121583591&loc=d3e4304-108586 Reference 3: 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=121583591&loc=d3e4332-108586 + Details
Name: | us-gaap_ConversionOfStockSharesConverted1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of investment in equity method investee and investment in and advance to affiliate. + 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 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Percentage of subsidiary's or equity investee's stock owned by parent company after stock transaction. + References No definition available. + Details
Name: | us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- 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_ScheduleOfEquityMethodInvestmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_CounterpartyNameAxis=omex_GregStemmMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | omex_InvestmentsIssuerAxis=omex_ChathamRockPhosphateLtdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=omex_NeptuneMineralsIncorporatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=omex_CommonClassBNonVotingSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=omex_SeriesAPreferredNonVotingSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=omex_DoradoOceanResourcesLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |