Financial Instruments and Fair Value Disclosures - (Unobservable Inputs Used in Discounted Cash Flow Model to Determine the Fair Value of Communities) (Details) $ / homes in Thousands, $ in Millions	9 Months Ended
	Aug. 31, 2018 USD ($) $ / homes homes community	Aug. 31, 2017 USD ($) $ / homes homes community
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Valuation adjustments to inventory | $	$ 29.4	$ 7.5
Number of homes impaired | homes	688	469
Number of communities impaired | community	5	6
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Carrying value of homesites impaired | $	$ 56.5	$ 12.0
Average selling price | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Unobservable inputs | $ / homes	233,000	125,000
Average selling price | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Unobservable inputs | $ / homes	843,000	567,000
Absorption rate per quarter (homes) | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Unobservable inputs	4	4
Absorption rate per quarter (homes) | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Unobservable inputs	16	10
Discount rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Unobservable inputs	0.20	0.20