Fair Value Disclosures (Level 4 Inv Impair inputs) (Details 2)	3 Months Ended								9 Months Ended	12 Months Ended
	Oct. 31, 2019 USD ($) Homes_sold	Jul. 31, 2019 USD ($) Homes_sold	Apr. 30, 2019 USD ($) Homes_sold	Jan. 31, 2019 USD ($) Homes_sold	Oct. 31, 2018 USD ($)	Jul. 31, 2018 USD ($)	Apr. 30, 2018 USD ($)	Jan. 31, 2018 USD ($)	Jul. 31, 2018 USD ($)	Oct. 31, 2018 USD ($)
Fair value inputs, assets, quantitative information [Line Items]
Revenues										$ 7,143,258,000
Operating communities [Member] | Minimum [Member]
Fair value inputs, assets, quantitative information [Line Items]
Average selling price									$ 10,000
Operating communities [Member] | Maximum [Member]
Fair value inputs, assets, quantitative information [Line Items]
Average selling price									$ 155,000
Operating communities [Member] | Minimum [Member]
Fair value inputs, assets, quantitative information [Line Items]
Average selling price	$ 478,000	$ 530,000	$ 372,000	$ 836,000	$ 470,000	$ 0	$ 485,000	$ 381,000
Sales Pace	2	2	2	2	4	0	10	7
Fair Value Input, Discount Rate	13.80%	7.80%	12.00%	12.50%	13.50%	0.00%	16.90%	13.80%
Operating communities [Member] | Maximum [Member]
Fair value inputs, assets, quantitative information [Line Items]
Average selling price	$ 857,000	$ 1,113,000	$ 1,915,000	$ 13,495,000	$ 1,071,000	$ 0	$ 522,000	$ 1,029,000
Sales Pace	5	9	19	12	23	0	16	10
Fair Value Input, Discount Rate	14.50%	13.00%	26.00%	15.80%	16.30%	0.00%	16.90%	19.00%