Document and Entity Information (USD $)	12 Months Ended
	Nov. 30, 2011	Dec. 31, 2011	May 31, 2011
Document and Entity Information [Abstract]
Entity Registrant Name	KB HOME
Entity Central Index Key	0000795266
Document Type	10-K
Document Period End Date	Nov. 30, 2011
Amendment Flag	false
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--11-30
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 1,081,292,301
Entity Common Stock Shares Outstanding		77,092,268