Fair Value Disclosures (Level 4 Inv Impair inputs) (Details 2) $ in Thousands	3 Months Ended
	Oct. 31, 2018 USD ($) Homes_sold	Jul. 31, 2018 USD ($) Homes_sold	Apr. 30, 2018 USD ($) Homes_sold	Jan. 31, 2018 USD ($) Homes_sold	Oct. 31, 2017 USD ($)	Jul. 31, 2017 USD ($)	Apr. 30, 2017 USD ($)	Jan. 31, 2017 USD ($)
Operating communities [Member] | Minimum [Member]
Fair value inputs, assets, quantitative information [Line Items]
Average selling price	$ 470	$ 0	$ 485	$ 381	$ 467	$ 465	$ 827	$ 692
Sales Pace	4	0	10	7	12	3	6	4
Fair Value Inputs, Discount Rate	13.50%	0.00%	16.90%	13.80%	16.40%	16.50%	16.30%	16.30%
Operating communities [Member] | Maximum [Member]
Fair value inputs, assets, quantitative information [Line Items]
Average selling price	$ 1,071	$ 0	$ 522	$ 1,029	$ 540	$ 754	$ 856	$ 880
Sales Pace	23	0	16	10	30	10	11	12
Fair Value Inputs, Discount Rate	16.30%	0.00%	16.90%	19.00%	16.40%	19.50%	16.30%	16.30%
Operating communities [Member] | Minimum [Member]
Fair value inputs, assets, quantitative information [Line Items]
Average selling price		$ 10
Operating communities [Member] | Maximum [Member]
Fair value inputs, assets, quantitative information [Line Items]
Average selling price		$ 155