Price of a single warrant of warrants issued during the period.

No definition available.

Name:	graf_ClassOfWarrantOrRightIssuePricePerWarrant
Namespace Prefix:	graf_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of warrants or rights issued during the period.

+ References

No definition available.

+ Details

Name:	graf_ClassOfWarrantOrRightIssued
Namespace Prefix:	graf_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The lock in period after the completion of initial business combination for the sponsor and other officers for the warrants issued .

+ References

No definition available.

+ Details

Name:	graf_ClassOfWarrantOrRightRestrictionsOnTransferAssignOrSellForPeriodOfTimeAfterBusinessCombinationCompletion
Namespace Prefix:	graf_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- 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

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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-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

+ Details

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

- Definition

Number of securities into which each warrant or right may be converted. For example, but not limited to, each warrant may be converted into two shares.

+ References

+ Details

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

- Definition

The cash inflow from issuance of rights to purchase common shares at predetermined price (usually issued together with corporate debt).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 14
-Subparagraph (a)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-14

+ Details

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

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=graf_PrivatePlacementWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	srt_CounterpartyNameAxis=graf_SponsorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=graf_CantorFitzgeraldAndCo.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

PRIVATE PLACEMENT (Details) - USD ($)		6 Months Ended	12 Months Ended
PRIVATE PLACEMENT (Details) - USD ($)	Jun. 27, 2024	Jun. 30, 2026	Dec. 31, 2025
SHAREHOLDERS' DEFICIT
Exercise price of warrants (in dollar per share)		$ 11.5	$ 11.5
Lock in period of warrants after completion of initial business combination for sponsor and company's officers and directors (in days)		30 days	30 days
Private Placement Warrants
SHAREHOLDERS' DEFICIT
Number of warrants purchased (in shares)	6,000,000
Purchase price per warrant (in dollar per share)	$ 1
Proceeds from issuance of warrants	$ 6,000,000
Exercise price of warrants (in dollar per share)	$ 11.5
Lock in period of warrants after completion of initial business combination for sponsor and company's officers and directors (in days)	30 days
Class A Ordinary Shares \| Private Placement Warrants
SHAREHOLDERS' DEFICIT
Number of shares issuable on exercise of each warrant (in shares)	1
Sponsor \| Private Placement Warrants
SHAREHOLDERS' DEFICIT
Number of warrants purchased (in shares)	4,000,000
Cantor Fitzgerald And Co. \| Private Placement Warrants
SHAREHOLDERS' DEFICIT
Number of warrants purchased (in shares)	2,000,000