Financial Instruments and Fair Value Disclosures - (Narrative) (Details) $ in Millions	3 Months Ended
	Feb. 28, 2019 USD ($) community homes	Feb. 28, 2018 USD ($) community communities homes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Active communities	1,287	1,340
Number of communities assessed for impairment | community	54	20
Number of homesites assessed for impairment | homes	3,513	1,184
Inventory with potential indicators of impairment	$ 463.5	$ 267.6
Valuation adjustments to inventory		$ 6.9
Number of homes impaired | homes		114
Number of communities impaired | community		1
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Carrying value of homesites impaired		$ 17.5
Commitments to Sell MBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Open commitments	$ 1,300.0
Mortgage Prepayment Rate | Level 3 | Mortgage servicing rights | Financial Services
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Unobservable inputs for valuation of mortgage servicing rights	0.130
Discount Rate | Level 3 | Mortgage servicing rights | Financial Services
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Unobservable inputs for valuation of mortgage servicing rights	0.124
Delinquency Rate | Level 3 | Mortgage servicing rights | Financial Services
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Unobservable inputs for valuation of mortgage servicing rights	0.085