Inventory Impairments and Land Option Contract Abandonments (Narratives) (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	May 31, 2017 USD ($) lot delivery property	May 31, 2016 USD ($) lot delivery property	May 31, 2017 USD ($) lot delivery property	May 31, 2016 USD ($) lot delivery property	Nov. 30, 2016 USD ($) property
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impairment of Real Estate	$ 4,302,000	$ 9,930,000	$ 7,519,000	$ 11,276,000	$ 49,600,000
Number of Land Parcels or Communities Associated with Non Cash Inventory Impairment Charges | property	2		4
Number of land parcels or communities evaluated for recoverability | property			43	32
Carrying Value of Communities or Land Parcels Evaluated for Impairment	$ 381,100,000	$ 248,700,000	$ 381,100,000	$ 248,700,000
Aggregate carrying value of inventory impacted by pretax, noncash inventory impairment charges	$ 195,100,000		$ 195,100,000		$ 215,300,000
Number of communities and various other land parcels impacted by pretax, noncash inventory impairment charges	25		25		28
Land Option Contract Abandonment Lots | lot	134	312	520	492
Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Estimate Input at Average Selling Price	$ 399,800	$ 280,100	$ 399,800	$ 310,000
Fair Value Estimate Input, Delivery For Period | delivery	4	4	4	4
Fair Value Inputs, Discount Rate	18.00%	20.00%	18.00%	20.00%
Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Estimate Input at Average Selling Price	$ 231,000	$ 280,100	$ 231,000	$ 280,100
Fair Value Estimate Input, Delivery For Period | delivery	3	4	3	1
Fair Value Inputs, Discount Rate	18.00%	20.00%	17.00%	17.00%
Land Option Contract Abandonment [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Payments to Acquire Land	$ (1,699,000)	$ (1,810,000)	$ (2,490,000)	$ (2,430,000)
West Coast [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impairment of Real Estate	3,144,000	$ 4,574,000	3,144,000	$ 4,574,000
Number of Land Parcels or Communities Associated with Non Cash Inventory Impairment Charges | property		1		1
West Coast [Member] | Land Option Contract Abandonment [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Payments to Acquire Land	(1,044,000)	$ (261,000)	(1,835,000)	$ (421,000)
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	(518,000)	0	(518,000)	(460,000)
Southeast [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impairment of Real Estate	1,158,000	5,356,000	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	$ (137,000)		$ (137,000)
Land Held for Future Development [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impairment of Real Estate		4,600,000		4,600,000
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)		(1,438,000)
Metro Washington, D.C. [Member] | Land [Member] | Southeast [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impairment of Real Estate		$ 5,400,000		$ 5,400,000
Number of Land Parcels or Communities Associated with Non Cash Inventory Impairment Charges | property		2		2