Note 5 - Related Party Lease (Details Textual) - Lease Agreement with Z3 Investment LLC [Member]		3 Months Ended
Mar. 24, 2022 USD ($) ft²	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)
Lessee, Operating Lease, Term of Contract	5 years
Area of Real Estate Property \| ft²	35,000
Second Six Months, Rental Expense, Operating Lease	$ 108,000
Percent Increase, Annual Rental Expense	4.00%
Operating lease, Operating Expenses, Per Month	$ 20,000
Lessee, Operating Lease, Renewal Term	5 years
Operating Lease, Payments		$ 324,000	$ 311,000

The operating expenses per month of a operating lease.

No definition available.

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Namespace Prefix:	thmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The percent of annual monthly rental increases under the operating lease agreement.

+ References

No definition available.

+ Details

Name:	thmo_PercentIncreaseAnnualRentalExpense
Namespace Prefix:	thmo_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Second six months, monthly rental expense under the operating lease agreement.

+ References

No definition available.

+ Details

Name:	thmo_SecondSixMonthsRentalExpenseOperatingLease
Namespace Prefix:	thmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Area of a real estate property.

+ References

No definition available.

+ Details

Name:	us-gaap_AreaOfRealEstateProperty
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

Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479041/842-20-45-5

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (g)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-4

+ Details

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

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=thmo_LeaseAgreementWithZ3InvestmentLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: