XML 46 R37.htm IDEA: XBRL DOCUMENT
v3.22.2.2

Commitments and Contingent Liabilities (Details) $ in Thousands, $ in Millions | 3 Months Ended | 9 Months Ended | 12 Months Ended | 60 Months Ended |  |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2022 USD ($) | Sep. 30, 2021 USD ($) | Sep. 30, 2022 USD ($) | Sep. 30, 2021 USD ($) | Dec. 31, 2024 AUD ($) | Dec. 31, 2023 AUD ($) | Dec. 31, 2022 AUD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($)
Commitments and Contingent Liabilities |  |  |  |  |  |  |  |  |  |
Exploration and evaluation expenses | $ 22,663 | $ 23,848 | $ 40,340 | $ 80,181 |  |  |  |  |  |
Nauru Ocean Resources Inc |  |  |  |  |  |  |  |  |  |
Commitments and Contingent Liabilities |  |  |  |  |  |  |  |  |  |
NORI spend in 2022 |  |  |  |  |  |  |  |  | $ 25,000 | $ 40,000
Marawa Research and Exploration Limited |  |  |  |  |  |  |  |  |  |
Commitments and Contingent Liabilities |  |  |  |  |  |  |  |  |  |
Exploration and evaluation expenses |  |  |  |  | $ 2 | $ 3 | $ 1 |  |  |
Tonga Off shore Mining Limited |  |  |  |  |  |  |  |  |  |
Commitments and Contingent Liabilities |  |  |  |  |  |  |  |  |  |
Spending committed |  |  |  |  |  |  |  | $ 30,000 |  |
Exploration and evaluation expenses |  |  |  |  |  |  |  | $ 13,300 |  |
Long-term Purchase Commitment, Period |  |  |  |  |  |  |  | 5 years |  |

X
- Definition Funding Commitments Year One + References No definition available. + Details
Name: | tmc_FundingCommitmentsYearOne
Namespace Prefix: | tmc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Exploration expenses (including prospecting) related to oil and gas producing entities and would be included in operating expenses of that entity. Costs incurred in identifying areas that may warrant examination and in examining specific areas that are considered to have prospects of containing oil and gas reserves, including costs of drilling exploratory wells and exploratory-type stratigraphic test wells. Exploration costs may be incurred both before acquiring the related property (sometimes referred to in part as prospecting costs) and after acquiring the property. Principal types of exploration costs, which include depreciation and applicable operating costs of support equipment and facilities and other costs of exploration activities, are: (i) Costs of topographical, geographical and geophysical studies, rights of access to properties to conduct those studies, and salaries and other expenses of geologists, geophysical crews, and others conducting those studies. Collectively, these are sometimes referred to as geological and geophysical or "G&G" costs. (ii) Costs of carrying and retaining undeveloped properties, such as delay rentals, ad valorem taxes on properties, legal costs for title defense, and the maintenance of land and lease records. (iii) Dry hole contributions and bottom hole contributions. (iv) Costs of drilling and equipping exploratory wells. (v) Costs of drilling exploratory-type stratigraphic test wells. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 23 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=126939881&loc=d3e62136-109447 + Details
Name: | us-gaap_ExplorationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The minimum amount the entity agreed to spend under the long-term purchase commitment. + References No definition available. + Details
Name: | us-gaap_LongTermPurchaseCommitmentAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_LongTermPurchaseCommitmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_LongtermPurchaseCommitmentPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=tmc_NauruOceanResourcesIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=tmc_MarawaResearchAndExplorationLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=tmc_TongaOffshoreMiningLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |