Inventory Impairments and Land Option Contract Abandonments (Narratives) (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Aug. 31, 2017 USD ($) lot delivery property	Aug. 31, 2016 USD ($) lot delivery property	Aug. 31, 2017 USD ($) lot delivery property	Aug. 31, 2016 USD ($) lot delivery property	Nov. 30, 2016 USD ($) property
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impairment of Real Estate	$ 7,094,000	$ 2,579,000	$ 14,613,000	$ 13,855,000	$ 49,600,000
Number of Land Parcels or Communities Associated with Non Cash Inventory Impairment Charges | property			6
Number of land parcels or communities evaluated for recoverability | property			49	43
Carrying Value of Communities or Land Parcels Evaluated for Impairment	436,700,000	$ 350,000,000	$ 436,700,000	$ 350,000,000
Aggregate carrying value of inventory impacted by pretax, noncash inventory impairment charges	$ 209,100,000		$ 209,100,000		$ 215,300,000
Number of communities and various other land parcels impacted by pretax, noncash inventory impairment charges	26		26		28
Land Option Contract Abandonment Lots | lot	119	50	639	542
Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Estimate Input at Average Selling Price	$ 1,576,500	$ 486,000	$ 1,576,500	$ 486,000
Fair Value Estimate Input, Delivery For Period | delivery	4	3	4	4
Fair Value Inputs, Discount Rate	18.00%	17.00%	18.00%	20.00%
Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Estimate Input at Average Selling Price	$ 207,100	$ 351,600	$ 207,100	$ 280,100
Fair Value Estimate Input, Delivery For Period | delivery	2	2	2	1
Fair Value Inputs, Discount Rate	17.00%	17.00%	17.00%	17.00%
Land Option Contract Abandonment [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Payments to Acquire Land	$ (1,019,000)	$ (473,000)	$ (3,509,000)	$ (2,903,000)
West Coast [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impairment of Real Estate	$ 4,992,000	$ 2,579,000	$ 8,136,000	$ 7,153,000
Number of Land Parcels or Communities Associated with Non Cash Inventory Impairment Charges | property	1	2	1	2
West Coast [Member] | Land Option Contract Abandonment [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Payments to Acquire Land	$ (903,000)	$ (270,000)	$ (2,738,000)	$ (691,000)
Central [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impairment of Real Estate	0	0	0	787,000
Central [Member] | Land Option Contract Abandonment [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Payments to Acquire Land	0	0	(518,000)	(460,000)
Southeast [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impairment of Real Estate	0	0	3,032,000	5,915,000
Southeast [Member] | Land Option Contract Abandonment [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Payments to Acquire Land	$ (116,000)	(61,000)	$ (253,000)	(1,499,000)
Land Held for Future Development [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impairment of Real Estate				$ 5,200,000
Number of Land Parcels or Communities Associated with Non Cash Inventory Impairment Charges | property	2		6
Land Held for Future Development [Member] | West Coast [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Number of Land Parcels or Communities Associated with Non Cash Inventory Impairment Charges | property				1
Land Held for Future Development [Member] | Southeast [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Number of Land Parcels or Communities Associated with Non Cash Inventory Impairment Charges | property				1
Metro Washington, D.C. [Member] | Southeast [Member] | Land Option Contract Abandonment [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Payments to Acquire Land		$ (1,438,000)		$ (1,400,000)
Metro Washington, D.C. [Member] | Land [Member] | Southeast [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impairment of Real Estate				$ 5,400,000
Number of Land Parcels or Communities Associated with Non Cash Inventory Impairment Charges | property				2