Inventory Impairments and Land Option Contract Abandonments (Narratives) (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Aug. 31, 2012 property	Aug. 31, 2011 lot property	Aug. 31, 2012 property	Aug. 31, 2011 lot property	Nov. 30, 2011 property
Inventory Impairments and Land Option Contract Abandonments [Abstract]
Number of land parcels or communities evaluated for recoverability	33	33	109	97
Pretax, noncash inventory impairment charges	$ 6,403,000	$ 328,000	$ 22,912,000	$ 21,414,000	$ 22,700,000
Number of land parcels or communities associated with non cash inventory impairment charges	4	1	11	9
Post impairment fair value	3,200,000	1,100,000	30,600,000	29,900,000
Charges related to adjustment to fair value of real estate		18,100,000
Aggregate carrying value of inventory impacted by pretax, noncash inventory impairment charges	334,400,000		334,400,000		338,500,000
Number of communities and various other land parcels impacted by pretax, noncash inventory impairment charges	48		48		53
Land option contract abandonment charges	$ 0	$ 834,000	$ 0	$ 2,093,000
Number of lots on which abandonment charges are recognized		209		467
Remaining useful life in addition to specified useful lives (in years)			1 year
Specified period of remaining useful lives (in years)			10 years
Expected realization period of inventory maximum (in years)			5 years