Annual committed lease payments per acre.

No definition available.

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Namespace Prefix:	thmg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Annual committed lease payments per acre final seven-year period.

+ References

No definition available.

+ Details

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Namespace Prefix:	thmg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Annual committed lease payments per acre for the first seven-year period.

+ References

No definition available.

+ Details

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Namespace Prefix:	thmg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Annual committed lease payments per acre for the second seven-year period.

+ References

No definition available.

+ Details

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Namespace Prefix:	thmg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Annual committed lease payments per acre per original agreement for six year term.

+ References

No definition available.

+ Details

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Namespace Prefix:	thmg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount bid by the company for awarded mineral lease rights.

+ References

No definition available.

+ Details

Name:	thmg_LeaseWinningBidAmount
Namespace Prefix:	thmg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the total annual lease payments.

+ References

No definition available.

+ Details

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Namespace Prefix:	thmg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Area of land held.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-3

+ Details

Name:	us-gaap_LesseeOperatingLeaseRenewalTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_LesseeOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
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

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

- Definition

Amount of expense related to royalty payments under a contractual arrangement such as payment for mineral and drilling rights and use of technology or intellectual property.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(3))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

+ Details

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

- Details

Name:	thmg_TargetAreaAxis=thmg_WilliamAndNitaLowryMember
Namespace Prefix:
Data Type:	na
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- Details

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Namespace Prefix:
Data Type:	na
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Period Type:

- Details

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Namespace Prefix:
Data Type:	na
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- Details

Name:	thmg_TargetAreaAxis=thmg_LequericaAndSonsIncMember
Namespace Prefix:
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- Details

Name:	thmg_TargetAreaAxis=thmg_IdahoStateMineralLeaseMember
Namespace Prefix:
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Mineral Interest Commitments (Narrative) (Details)				1 Months Ended
Mineral Interest Commitments (Narrative) (Details)	Oct. 24, 2025 USD ($)	Jun. 02, 2025 USD ($) a	Oct. 24, 2008 USD ($) a	Mar. 31, 2026 USD ($) a	Aug. 22, 2025 USD ($) a
William And Nita Lowry [Member]
Other Commitments [Line Items]
Lease contract			6 years
Area of land \| a			376
Annual committed lease payments per acre per original agreement for six year term			$ 20
Michael Lowry [Member]
Other Commitments [Line Items]
Lease renewal term	21 years
Annual committed lease payments per acre for the first seven year period	$ 40
Annual committed lease payments per acre for the second seven year period	50
Annual committed lease payments per acre for the final seven year period	$ 60
Kevin and Jo Lootens Living Trust [Member]
Other Commitments [Line Items]
Lease contract		7 years
Area of land \| a		18
Annual committed lease payments per acre per original agreement for six year term		$ 30
Lease renewal term		10 years
Annual Committed Lease Payments Per Acre		$ 40
Lequerica & Sons, Inc. [Member]
Other Commitments [Line Items]
Area of land \| a					432
Annual committed lease payments per acre per original agreement for six year term					$ 30
Lease renewal term					7 years
Annual Committed Lease Payments Per Acre					$ 40
Idaho State Mineral Lease [Member]
Other Commitments [Line Items]
Lease contract				20 years
Area of land \| a				3,500
Total annual lease payments				$ 10,495
Winning bid amount				210,000
Royalty				$ 10,000