Percent of stock convertible

No definition available.

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- Definition

Price of the entity's common stock which would be required to be attained for the conversion feature embedded in the debt instrument to become effective.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 235
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-Section S99
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 210
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-Section S99
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-Subparagraph (SX 210.5-02.19(a))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- 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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585

+ Details

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

- Definition

Amount of consideration received by subsidiary or equity investee in exchange for shares of stock issued or sold. Includes amount of cash received, fair value of noncash assets received, and fair value of liabilities assumed by the investor.

+ References

No definition available.

+ Details

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

- Definition

The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
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:	num: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:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares issued in lieu of cash for services contributed to the entity. Number of shares includes, but is not limited to, shares issued for services contributed by vendors and founders.

+ References

No definition available.

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesIssuedForServices
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of new stock issued during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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-Name Accounting Standards Codification
-Topic 210
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Value of stock issued in lieu of cash for services contributed to the entity. Value of the stock issued includes, but is not limited to, services contributed by vendors and founders.

+ References

No definition available.

+ Details

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

- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=kvsb_ForwardPurchaseAgreementMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_OverAllotmentOptionMember
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Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_StatementClassOfStockAxis=kvsb_ClassBFounderSharesMember
Namespace Prefix:
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Balance Type:
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- Details

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Related Party Transactions - Additional Information (Detail) - USD ($)						2 Months Ended	5 Months Ended
	Mar. 31, 2021	Mar. 30, 2021	Mar. 26, 2021	Mar. 10, 2021	Jan. 29, 2021	Mar. 31, 2021	Jun. 30, 2021	Feb. 08, 2021
Due to related parties, current							$ 5,300
Stock Issued During Period, Value, Issued for Services						$ 0
Proceeds from sale of Private Placement Shares	$ 11,326,880					$ 11,326,880	407,339,180
Sponser [Member]
Maximum Borrowing Capacity								$ 300,000
Line of Credit Facility, Current Borrowing Capacity							$ 5,300
Founder shares [Member]
Stock Issued During Period, Shares, Issued for Services					10,000,000
Stock Issued During Period, Value, Issued for Services					$ 25,000
Class A Common Stock
Stock Issued During Period, Shares, New Issues			41,634,412
Class A Common Stock \| Triggering Events Stock Trading Price One [Member]
Conversion of share, price per share						$ 20.00
Class A Common Stock \| Triggering Events Stock Trading Price Two [Member]
Conversion of share, price per share						25.00
Class A Common Stock \| Triggering Events Stock Trading Price Three [Member]
Conversion of share, price per share						$ 30.00
Class A Common Stock \| Private Placement
Stock Issued During Period, Shares, New Issues	32,688		1,100,000			1,132,688
Shares issued, price per share	$ 10.00		$ 10.00			$ 10.00
Proceeds from sale of Private Placement Shares	$ 326,880		$ 11,000,000
Class A Common Stock \| Forward Purchase Agreement [Member]
Sale of stock, number of shares issued in transaction	1,000,000
Sale of stock, price per share	$ 10.00					$ 10.00
Sale of stock, consideration received per transaction	$ 10,000,000
Class A Common Stock \| Over-Allotment Option
Stock Issued During Period, Shares, New Issues		16,344,118	1,634,412
Shares issued, price per share			$ 10.00
Class B Common Stock
Stock Issued During Period, Shares, Issued for Services				120,000
Stock Issued During Period, Value, Issued for Services				$ 300
Class B Founder Shares [Member]
Stock Issued During Period, Shares, Issued for Services					5,000,000
Percent of stock convertible							15.00%
Class K Founder Shares
Stock Issued During Period, Shares, Issued for Services					5,000,000
Percent of stock convertible							30.00%