Supplemental Guarantor Information (Details 1) (USD $) In Thousands	Aug. 31, 2011	Nov. 30, 2010
Homebuilding:
Cash and cash equivalents	$ 477,406	$ 904,401
Restricted cash	113,186	115,477
Receivables	79,180	108,048
Inventories	1,900,580	1,696,721
Investments in unconsolidated joint ventures	51,255	105,583
Other assets	78,382	150,076
Homebuilding	2,699,989	3,080,306
Financial services	21,828	29,443
Investments in subsidiaries	0	0
Total assets	2,721,817	3,109,749
Homebuilding:
Accounts payable, accrued expenses and other liabilities	699,826	699,722
Mortgages and notes payable	1,586,703	1,775,529
Homebuilding	2,286,529	2,475,251
Financial services	3,321	2,620
Intercompany	0	0
Total stockholders' equity	431,967	631,878
Total liabilities and Stockholders' equity	2,721,817	3,109,749
KB Home Corporate[Member]
Homebuilding:
Cash and cash equivalents	422,406	770,603
Restricted cash	65,021	88,714
Receivables	(72,889)	4,205
Inventories	0	0
Investments in unconsolidated joint ventures	0	0
Other assets	69,662	68,166
Homebuilding	484,200	931,688
Financial services	0	0
Investments in subsidiaries	10,641	36,279
Total assets	494,841	967,967
Homebuilding:
Accounts payable, accrued expenses and other liabilities	121,480	124,609
Mortgages and notes payable	1,533,212	1,632,362
Homebuilding	1,654,692	1,756,971
Financial services	0	0
Intercompany	(1,591,818)	(1,420,882)
Total stockholders' equity	431,967	631,878
Total liabilities and Stockholders' equity	494,841	967,967
Guarantor Subsidiaries [Member]
Homebuilding:
Cash and cash equivalents	13,466	3,619
Restricted cash	0	0
Receivables	10,518	6,271
Inventories	832,252	774,102
Investments in unconsolidated joint ventures	38,216	37,007
Other assets	607	72,805
Homebuilding	895,059	893,804
Financial services	0	0
Investments in subsidiaries	0	0
Total assets	895,059	893,804
Homebuilding:
Accounts payable, accrued expenses and other liabilities	140,274	150,260
Mortgages and notes payable	24,118	112,368
Homebuilding	164,392	262,628
Financial services	0	0
Intercompany	741,030	631,176
Total stockholders' equity	(10,363)	0
Total liabilities and Stockholders' equity	895,059	893,804
Non-Guarantor Subsidiaries [Member]
Homebuilding:
Cash and cash equivalents	41,534	130,179
Restricted cash	48,165	26,763
Receivables	141,551	97,572
Inventories	1,068,328	922,619
Investments in unconsolidated joint ventures	13,039	68,576
Other assets	8,113	9,105
Homebuilding	1,320,730	1,254,814
Financial services	21,828	29,443
Investments in subsidiaries	0	0
Total assets	1,342,558	1,284,257
Homebuilding:
Accounts payable, accrued expenses and other liabilities	438,072	424,853
Mortgages and notes payable	29,373	30,799
Homebuilding	467,445	455,652
Financial services	3,321	2,620
Intercompany	850,788	789,706
Total stockholders' equity	21,004	36,279
Total liabilities and Stockholders' equity	1,342,558	1,284,257
Consolidating Adjustments [Member]
Homebuilding:
Cash and cash equivalents	0	0
Restricted cash	0	0
Receivables	0	0
Inventories	0	0
Investments in unconsolidated joint ventures	0	0
Other assets	0	0
Homebuilding	0	0
Financial services	0	0
Investments in subsidiaries	(10,641)	(36,279)
Total assets	(10,641)	(36,279)
Homebuilding:
Accounts payable, accrued expenses and other liabilities	0	0
Mortgages and notes payable	0	0
Homebuilding	0	0
Financial services	0	0
Intercompany	0	0
Total stockholders' equity	(10,641)	(36,279)
Total liabilities and Stockholders' equity	$ (10,641)	$ (36,279)