Represents the information pertaining to the class of securities underlying warrants or rights issued by the entity.

No definition available.

Name:	gfuz_ClassOfWarrantOrRightIssued
Namespace Prefix:	gfuz_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of warrants or rights issued as a consideration for finders' fees.

+ References

No definition available.

+ Details

Name:	gfuz_ClassOfWarrantOrRightIssuedAsConsiderationForFindersFees
Namespace Prefix:	gfuz_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of financing costs incurred during the period.

+ References

No definition available.

+ Details

Name:	gfuz_FinancingCosts
Namespace Prefix:	gfuz_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of financing costs related to warrants issued as a consideration for finders' fees incurred during the period.

+ References

No definition available.

+ Details

Name:	gfuz_FinancingCostsRelatedToWarrantsIssuedAsConsiderationForFindersFees
Namespace Prefix:	gfuz_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow from issuance of Simple Agreements for Future Equity (SAFE) arrangements.

+ References

No definition available.

+ Details

Name:	gfuz_ProceedsFromIssuanceOfSimpleAgreementsForFutureEquity
Namespace Prefix:	gfuz_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow from issuance of rights to purchase common shares at predetermined price, which is issued as a consideration for finders' fees.

+ References

No definition available.

+ Details

Name:	gfuz_ProceedsFromIssuanceOfWarrantsIssuedAsConsiderationForFindersFees
Namespace Prefix:	gfuz_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of change in the fair value of a financial liability resulting from a decrease in a significant valuation input, with other variables unchanged.

+ References

No definition available.

+ Details

Name:	gfuz_SensitivityAnalysisOfFairValueFinancialLiabilityImpactOfDecreaseInInput
Namespace Prefix:	gfuz_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of change in the fair value of a financial liability resulting from an increase in a significant valuation input, with other variables unchanged.

+ References

No definition available.

+ Details

Name:	gfuz_SensitivityAnalysisOfFairValueFinancialLiabilityImpactOfIncreaseInInput
Namespace Prefix:	gfuz_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage change in the fair value of a financial liability resulting from a change in a significant valuation input, with other variables unchanged.

+ References

No definition available.

+ Details

Name:	gfuz_SensitivityAnalysisOfFairValueFinancialLiabilityPercentageImpactOfChangeInInput
Namespace Prefix:	gfuz_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage discount applied to the price per share in a qualifying equity financing or liquidity event for purposes of determining the conversion price of SAFE instruments.

+ References

No definition available.

+ Details

Name:	gfuz_SimpleAgreementsForFutureEquityConversionDiscountRate
Namespace Prefix:	gfuz_
Data Type:	dtr-types: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:	gfuz_SimpleAgreementsForFutureEquityLiabilitiesLineItems
Namespace Prefix:	gfuz_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage discount applied to the price per share in a liquidity event, including an initial public offering, direct listing, or special purpose acquisition company merger, for purposes of determining the conversion price of SAFE instruments.

+ References

No definition available.

+ Details

Name:	gfuz_SimpleAgreementsForFutureEquityLiquidityEventConversionDiscountRate
Namespace Prefix:	gfuz_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Aggregate gross proceeds that must be raised in an equity financing transaction or series of related transactions for the financing to qualify as a Qualifying Equity Financing under the terms of the SAFE agreement.

+ References

No definition available.

+ Details

Name:	gfuz_SimpleAgreementsForFutureEquityQualifyingEquityFinancingThresholdAmount
Namespace Prefix:	gfuz_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Maximum company valuation specified in the SAFE agreement used in determining the conversion price of SAFE instruments upon the occurrence of a qualifying equity financing or liquidity event.

+ References

No definition available.

+ Details

Name:	gfuz_SimpleAgreementsForFutureEquityValuationCapAmount
Namespace Prefix:	gfuz_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(4))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

+ Details

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

- Definition

Number of warrants or rights outstanding.

+ References

No definition available.

+ Details

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

- Definition

Value of outstanding derivative securities that permit the holder the right to purchase securities (usually equity) from the issuer at a specified price.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

+ Details

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

- Details

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

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_RelatedPartyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_NonrelatedPartyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=gfuz_SimpleAgreementsForFutureEquityRelatedLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MeasurementInputTypeAxis=gfuz_MeasurementInputEstimatedCommonSharePriceAtClosingOfSpecialPurposeAcquisitionCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputSharePriceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputPriceVolatilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=gfuz_SimpleAgreementsForFutureEquityLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=gfuz_SimpleAgreementsForFutureEquityWarrantLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

SAFE liabilities - Narratives (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended			3 Months Ended	6 Months Ended	12 Months Ended
	Jan. 01, 2026	Jan. 31, 2026	Dec. 31, 2025	Nov. 30, 2025	Jun. 30, 2026	Jun. 30, 2026	Dec. 31, 2025	Jul. 10, 2026	Dec. 31, 2024
SAFE liabilities
Gross proceeds from issuance of SAFEs						$ 200
SAFE conversion discount rate			25.00%	25.00%	25.00%	25.00%	25.00%
SAFE valuation cap amount			$ 500,000	$ 500,000	$ 500,000	$ 500,000	$ 500,000
SAFE liquidity event conversion discount rate			25.00%	25.00%	25.00%	25.00%	25.00%
Financing costs (note 11)					$ 2	$ 26	$ 3,693
Warrants outstanding			21,109,135		53,076,019	53,076,019	21,109,135		15,191,077
Warrant liability			$ 1,067				$ 1,067		$ 10
Minimum
SAFE liabilities
Qualifying equity financing threshold amount			100,000	$ 100,000		$ 100,000
Related party
SAFE liabilities
Gross proceeds from issuance of SAFEs							3,500
Non-related party
SAFE liabilities
Gross proceeds from issuance of SAFEs							40,919
Subsequent events
SAFE liabilities
Warrants outstanding								38,360,095
Total SAFE liabilities
SAFE liabilities
Gross proceeds from issuance of SAFEs		$ 200	44,307	44,307		$ 44,507	$ 44,307
Financing costs (note 11)			$ 3,559	3,559
Total SAFE liabilities \| Estimated common share value at closing of a SPAC
SAFE liabilities
Sensitivity analysis, fair value, financial liability, percentage impact			5.00%		3.00%	3.00%	5.00%
Sensitivity analysis, impact on financial liability fair value due to increase in input			$ 1,800		$ 1,500	$ 1,500	$ 1,800
Sensitivity analysis, impact on financial liability fair value due to decrease in input			$ 1,800		$ 1,500	$ 1,500	$ 1,800
Total SAFE liabilities \| Fair value of common shares
SAFE liabilities
Sensitivity analysis, fair value, financial liability, percentage impact			20.00%		20.00%	20.00%	20.00%
Sensitivity analysis, impact on financial liability fair value due to increase in input			$ 3,200		$ 4,000	$ 4,000	$ 3,200
Sensitivity analysis, impact on financial liability fair value due to decrease in input			$ 3,100		$ 3,900	$ 3,900	$ 3,100
Total SAFE liabilities \| Weighted average expected volatility
SAFE liabilities
Sensitivity analysis, fair value, financial liability, percentage impact			10.00%		20.00%	20.00%	10.00%
Sensitivity analysis, impact on financial liability fair value due to increase in input			$ 1,000		$ 2,200	$ 2,200	$ 1,000
Sensitivity analysis, impact on financial liability fair value due to decrease in input			1,000		$ 2,700	2,700	$ 1,000
Total SAFE liabilities \| Subsequent events
SAFE liabilities
Gross proceeds from issuance of SAFEs	$ 200
SAFEs
SAFE liabilities
Gross proceeds from issuance of SAFEs						350
SAFEs \| Related party
SAFE liabilities
Gross proceeds from issuance of SAFEs						$ 3,500
SAFE Warrants
SAFE liabilities
Gross proceeds from issuance of SAFEs			$ 350	$ 350
Warrants issued			11,006,350	11,006,350		11,056,430
Exercise price			$ 1.9968	$ 1.9968	$ 1.9749	$ 1.9749	$ 1.9968
Financing costs related to warrants issued as a consideration for finders' fees			$ 2,000	$ 2,000
Warrants issued as a consideration for finders' fees			3,625,000	3,625,000			3,625,000
Nominal cash proceeds received in exchange for the SAFE Warrants issued as consideration for the finders' fees			$ 112	$ 112		$ 112
Warrants outstanding			14,631,350				14,631,350
SAFE Warrants \| Related party
SAFE liabilities
Gross proceeds from issuance of SAFEs			$ 3,500	$ 3,500		$ 28
Warrants issued			876,646	876,646		876,646