Document and Entity Information - shares	6 Months Ended
	May 31, 2019	Feb. 28, 2019	Nov. 30, 2018	May 31, 2018	Feb. 28, 2018	Nov. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	KB HOME
Entity Central Index Key	0000795266
Document Type	10-Q
Document Period End Date	May 31, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--11-30
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock Shares Outstanding	88,226,142
Entity Current Reporting Status	Yes
Entity Shell Company	false
Grantor Stock Ownership Trust
Document Information [Line Items]
Common Stock, Shares, Outstanding	7,859,975	7,860,000	8,157,000	8,460,000	8,460,000	8,898,000