Commitments and Contingencies (Narratives) (Details) (USD $)	3 Months Ended			9 Months Ended
	Aug. 31, 2012 Home	May 31, 2012	Aug. 31, 2011	Aug. 31, 2012 Home	Aug. 31, 2011	Nov. 30, 2011 Home	May 31, 2011	Nov. 30, 2010
Loss Contingencies [Line Items]
Structural warranty provided by the company (in years)				10 years
Minimum warranty on electrical and other building systems (in years)				2 years
Maximum warranty on electrical and other building systems (in years)				5 years
Warranty for other components of a home (in years)				1 year
Warranty liability	$ 47,326,000	$ 50,866,000	$ 70,499,000	$ 47,326,000	$ 70,499,000	$ 67,693,000	$ 82,630,000	$ 93,988,000
Warranty liability associated with defective drywall	3,000,000			3,000,000		4,800,000
Number of homes containing or suspected of containing defective drywall	33			33		87
Number of affected homes on which repairs were resolved	56			56
Additional number of affected homes associated with repair costs	2			2
Payments made for the repair of homes containing defective drywall				2,700,000	11,800,000
Estimated additional charges for homes containing defective drywall				900,000	6,300,000
Accumulated number of homes identified affected associated with overall warranty liability				469
Accumulated number of affected homes on which repairs were resolved	436			436
Payments made as repair costs for homes containing defective drywall				43,200,000
Estimated repair costs for homes containing defective drywall				46,200,000
Warranty adjustment reduction of construction and land cost			7,400,000	11,200,000	7,400,000
Insurance recovery as reduction to construction and land costs	16,500,000	10,000,000
Estimated liabilities for construction defect	93,000,000			93,000,000		94,900,000
Expenses associated with self-insurance	1,200,000		2,100,000	5,800,000	6,700,000
Performance bonds	290,900,000			290,900,000		361,600,000
Letters of credit outstanding	45,200,000			45,200,000		63,800,000
Total deposits	29,800,000			29,800,000
Cash deposits	29,300,000			29,300,000		20,900,000
Letters of credit	500,000			500,000		1,700,000
Aggregate purchase price of land	$ 599,000,000			$ 599,000,000
Defective Drywall Material
Loss Contingencies [Line Items]
Number of lawsuits in which company is a defendant	10			10
Number of omnibus class action lawsuits	7			7
Florida State Court | Defective Drywall Material
Loss Contingencies [Line Items]
Number of lawsuits in which company is a defendant	2			2
Louisiana Federal Court | Defective Drywall Material
Loss Contingencies [Line Items]
Number of lawsuits in which company is a defendant	1			1