Investments in Unconsolidated Joint Ventures (Information for Investments in Unconsolidated Joint Ventures) (Details) $ in Thousands	3 Months Ended
Feb. 28, 2019 USD ($) lot joint_venture	Nov. 30, 2018 USD ($) lot joint_venture
Schedule of Equity Method Investments [Line Items]
Number of investments in unconsolidated joint ventures	6	6
Investments in unconsolidated joint ventures \| $	$ 57,134	$ 61,960
Number of Unconsolidated Joint Venture Lots Controlled Under Land Option Contracts \| lot	25	36
Number of Units in Real Estate Property \| lot	25
Long-term Purchase, Commitment, Amount \| $	$ 11,800
Investments in Unconsolidated Joint Ventures with Debt [Member]
Schedule of Equity Method Investments [Line Items]
Number of investments in unconsolidated joint ventures		1
Investments in Unconsolidated Joint Ventures with Purchase Commitments [Member]
Schedule of Equity Method Investments [Line Items]
Number of investments in unconsolidated joint ventures	1

Long-Term Purchase Commitment, Lots

No definition available.

Name:	kbh_LongTermPurchaseCommitmentLots
Namespace Prefix:	kbh_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of investments in unconsolidated joint ventures.

+ References

No definition available.

+ Details

Name:	kbh_NumberOfInvestmentsInUnconsolidatedJointVentures
Namespace Prefix:	kbh_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of Unconsolidated Joint Venture Lots Controlled Under Land Option Contracts

+ References

No definition available.

+ Details

Name:	kbh_NumberofUnconsolidatedJointVentureLotsControlledUnderLandOptionContracts
Namespace Prefix:	kbh_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of investment in equity method investee and investment in and advance to affiliate.

+ 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
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The minimum amount the entity agreed to spend under the long-term purchase commitment.

+ References

No definition available.

+ Details

Name:	us-gaap_LongTermPurchaseCommitmentAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

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

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=kbh_InvestmentsInUnconsolidatedJointVenturesWithDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=kbh_InvestmentsinUnconsolidatedJointVentureswithPurchaseCommitmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: