Document and Entity Information	9 Months Ended
	Aug. 31, 2012
Document and Entity Information [Abstract]
Entity Registrant Name	KB Home
Entity Central Index Key	0000795266
Document Type	10-Q
Document Period End Date	Aug. 31, 2012
Amendment Flag	false
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--11-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock Shares Outstanding	77,129,868