Class of warrants or right purchase.

No definition available.

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

- Definition

Class of warrants or right purchase during the year.

+ References

No definition available.

+ Details

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Namespace Prefix:	kcac_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Class Of Warrants Or Right Purchase Price Per Warrant

+ References

No definition available.

+ Details

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Namespace Prefix:	kcac_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Class of warrants or right underwritting discount purchase.

+ References

No definition available.

+ Details

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Namespace Prefix:	kcac_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Class of warrants or rights issued during the period.

+ References

No definition available.

+ Details

Name:	kcac_ClassOfWarrantsOrRightsIssuedDuringThePeriod
Namespace Prefix:	kcac_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Class of warrants or rights issued issue price per warrant.

+ References

No definition available.

+ Details

Name:	kcac_ClassOfWarrantsOrRightsIssuedIssuePricePerWarrant
Namespace Prefix:	kcac_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair value of private placement warrants.

+ References

No definition available.

+ Details

Name:	kcac_FairValueOfPrivatePlacementWarrants
Namespace Prefix:	kcac_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

Name:	kcac_PrivatePlacementLineItems
Namespace Prefix:	kcac_
Data Type:	xbrli:stringItemType
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

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

- Definition

Amount of expense (income) related to adjustment to fair value of warrant liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

+ Details

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

- Definition

The cash outflow associated with the repurchase of amount received from entity's raising of capital via private rather than public placement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 15
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-15

+ Details

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

- Definition

The cash inflow associated with the amount received from entity's raising of capital via private rather than public placement.

+ 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

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Namespace Prefix:	us-gaap_
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 (usually issued together with corporate debt).

+ References

+ Details

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

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_IPOMember
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- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_OverAllotmentOptionMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=kcac_UnderwritingMember
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Private Placement - Additional Information (Detail) - USD ($)			1 Months Ended	6 Months Ended
	Mar. 05, 2026	Mar. 03, 2026	Dec. 31, 2025	Jun. 30, 2026
Private Placement [Line Items]
Exercise Price of Warrants or Rights			$ 0.5	$ 0.5
Proceeds from issuance of warrants				$ 7,122,796
Class Of Warrants Or Right Purchase During The Year				61,333
Class of Warrants or Right Purchase			$ 2,000,000	$ 2,300,000
Proceeds from Issuance of Private Placement				$ 7,300,000
IPO [Member]
Private Placement [Line Items]
Exercise Price of Warrants or Rights				$ 0.25
Change in fair value of derivative liabilities				$ 5,714,753
Private Placement Warrants [Member]
Private Placement [Line Items]
Class of Warrants or Rights Issued During the Period			10,733,333	11,533,333
Class of warrants or Rights Issued Price Per Warrant			$ 0.44	$ 0.43
Payments for Repurchase of Private Placement				$ 5,000,000
Exercise Price of Warrants or Rights				$ 0.25
Change in fair value of derivative liabilities				$ 714,753
Class of Warrants or Right Underwritting Discount Purchase			2,666,667	3,005,334
Class Of Warrants Or Right Purchase Price Per Warrant			$ 0.75	$ 0.75
Fair Value of Private Placement Warrants		$ 773,471
Proceeds from Issuance of Private Placement		$ 1,526,528
Private Placement Warrants [Member] \| Over-Allotment Option [Member]
Private Placement [Line Items]
Class of Warrants or Right Underwritting Discount Purchase			3,066,667
Private Placement Warrants [Member] \| IPO [Member]
Private Placement [Line Items]
Exercise Price of Warrants or Rights				$ 0.5
Underwriting [Member] \| Over-Allotment Option [Member]
Private Placement [Line Items]
Class of Warrants or Right Purchase			$ 2,300,000
Underwriting [Member] \| Private Placement Warrants [Member]
Private Placement [Line Items]
Class of Warrants or Rights Issued During the Period			11,533,333
Exercise Price of Warrants or Rights			$ 0.43
Proceeds from issuance of warrants	$ 2,300,000		$ 5,000,000
Class of Warrants or Right Underwritting Discount Purchase			3,066,667
Class of Warrants or Right Purchase			$ 2,300,000
Sponsor [Member] \| Private Placement Warrants [Member]
Private Placement [Line Items]
Proceeds from issuance of warrants			$ 4,700,000
Class of Warrants or Right Underwritting Discount Purchase			2,666,667
Class of Warrants or Right Purchase			$ 2,000,000