Income Taxes (Details) - USD ($)		3 Months Ended		6 Months Ended
		May 31, 2017	May 31, 2016	May 31, 2017	May 31, 2016	Nov. 30, 2016
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Income tax expense	[1]	$ (20,200,000)	$ (9,200,000)	$ (27,400,000)	$ (12,100,000)
Effective Income Tax Rate Reconciliation, Percent	[1]	38.90%	37.10%	37.30%	29.60%
Income Tax Credits and Adjustments		$ 100,000	$ 400,000	$ 1,200,000	$ 3,700,000
Unrecognized Tax Benefits		100,000		100,000		$ 100,000
Net (increase) reduction in valuation allowance				0
Valuation allowance		24,800,000		24,800,000		24,800,000
Income Tax Contingency [Line Items]
Deferred Tax Assets, Gross		736,700,000		736,700,000		$ 763,800,000
Minimum [Member]
Income Tax Contingency [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit		0		0
Maximum [Member]
Income Tax Contingency [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit		$ 100,000		$ 100,000

[1] (a) Amounts reflect the favorable net impact of federal energy tax credits we earned from building energy-efficient homes. The net impact of these tax credits was $.1 million and $.4 million for the three months ended May 31, 2017 and 2016, respectively, and $1.2 million and $3.7 million for the six months ended May 31, 2017 and 2016, respectively.