The amount of deferred underwriting fee.

No definition available.

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Namespace Prefix:	kfii_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represent the number of additional units purchased.

+ References

No definition available.

+ Details

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

- Definition

Percentage of cash underwriting discount.

+ References

No definition available.

+ Details

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Namespace Prefix:	kfii_
Data Type:	dtr:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of deferred underwriting discount.

+ References

No definition available.

+ Details

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Namespace Prefix:	kfii_
Data Type:	dtr:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the underwriters option period from the date of Initial Public Offering.

+ References

No definition available.

+ Details

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Namespace Prefix:	kfii_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- 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

The cash inflow associated with the amount received from entity's first offering of stock to the public.

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

- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

No definition available.

+ Details

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

- Definition

Per share or per unit amount of equity securities issued.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_IPOMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_TypeOfArrangementAxis=kfii_UnderwritingAgreementMember
Namespace Prefix:
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Period Type:

Commitments and Contingencies (Details) - USD ($)		6 Months Ended
Commitments and Contingencies (Details) - USD ($)	Feb. 06, 2025	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025
Commitments and Contingencies [Line Items]
Gross proceeds (in Dollars)			$ 281,750,000
Deferred underwriting discount (in Dollars)		$ 10,062,500		$ 10,062,500
Initial Public Offering [Member]
Commitments and Contingencies [Line Items]
Gross proceeds (in Dollars)	$ 287,500,000
Over-Allotment Option [Member]
Commitments and Contingencies [Line Items]
Price per share	$ 10
Underwriting Agreement [Member]
Commitments and Contingencies [Line Items]
Underwriters days		45 days
Percentage of cash underwriting discount		2.00%
Percentage of deferred underwriting discount		3.50%
Deferred underwriting discount (in Dollars)		$ 10,062,500
Price per unit sold		$ 0.075
Underwriting Agreement [Member] \| Initial Public Offering [Member]
Commitments and Contingencies [Line Items]
Number of additional unit purchased (in Shares)		3,750,000
Gross proceeds (in Dollars)		$ 5,750,000
Price per unit sold		$ 0.275
Underwriting Agreement [Member] \| Over-Allotment Option [Member]
Commitments and Contingencies [Line Items]
Number of additional unit purchased (in Shares)	3,750,000
Price per share	$ 10