Variable Interest Entities (Details) (USD $) In Millions, unless otherwise specified	Aug. 31, 2012	Nov. 30, 2011
Variable Interest Entities [Abstract]
Cash deposits associated with land option and other similar contracts of unconsolidated VIE's	$ 6.4	$ 8.1
Aggregate purchase price of land option and other similar contracts of unconsolidated VIE's	316.9	122.1
Total cash deposits associated with land option and other similar contracts that were not VIE's	22.9	12.8
Aggregate purchase price of land option and other similar contracts that were not VIE's	282.1	223.0
Non refundable deposits related to land option and other similar contracts	29.3	20.9
Pre-acquisition costs related to land option contracts and other similar contracts	27.1	31.5
Outstanding letters of credit	0.5	1.7
Increase in inventories and accrued expenses and other liabilities	$ 20.0	$ 23.9

Acquisition costs related to land option contracts and other similar contracts.

No definition available.

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Data Type:	xbrli:monetaryItemType
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Cash deposits associated with land option and other similar contracts of non variable interest entities.

No definition available.

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Cash deposits associated with land option and other similar contracts of unconsolidated variable interest entities.

No definition available.

Name:	kbh_CashDepositsAssociatedWithLandOptionAndOtherSimilarContractsOfUnconsolidatedVariableInterestEntities
Namespace Prefix:	kbh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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Increase in inventories and accrued expenses and other liabilities due to land option and other similar contracts.

No definition available.

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Data Type:	xbrli:monetaryItemType
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Non-refundable cash deposits on land option and other similar contracts.

No definition available.

Name:	kbh_NonRefundableCashDepositsOnLandOptionAndOtherSimilarContracts
Namespace Prefix:	kbh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Outstanding letters of credit in lieu of cash deposits under certain land option or other similar contracts.

No definition available.

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Namespace Prefix:	kbh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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Purchase price associated with land option and other similar contracts of non variable interest entities.

No definition available.

Name:	kbh_PurchasePriceAssociatedWithLandOptionAndOtherSimilarContractsOfNonVariableInterestEntities
Namespace Prefix:	kbh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Purchase price associated with land option and other similar contracts of unconsolidated variable interest entities.

No definition available.

Name:	kbh_PurchasePriceAssociatedWithLandOptionAndOtherSimilarContractsOfUnconsolidatedVariableInterestEntities
Namespace Prefix:	kbh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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