Fair Value Disclosures (Level 4 inventory fv) (Details 3) $ in Thousands	3 Months Ended							9 Months Ended		12 Months Ended
	Jul. 31, 2020 USD ($)	Apr. 30, 2020 USD ($)	Jan. 31, 2020 USD ($)	Oct. 31, 2019 USD ($)	Jul. 31, 2019 USD ($)	Apr. 30, 2019 USD ($)	Jan. 31, 2019 USD ($)	Jul. 31, 2020 USD ($)	Jul. 31, 2019 USD ($)	Oct. 31, 2019 USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Inventory Write-down	$ 6,690				$ 4,679			$ 21,934	$ 31,636
Equity Method Investment, Nonconsolidated Investee or Group of Investees
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Revenues	$ 78,897				$ 179,608			291,179	511,226
Operating communities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Inventory Write-down								300		$ 31,075
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Operating communities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Number of Operating Communities Tested (in ones)	66	80	65	71	69	64	49
Number of Communities Impaired (in ones)	0	1	0	7	3	6	5
Fair Value Of Communities Net Of Impairment Charges	$ 0	$ 2,754	$ 0	$ 18,910	$ 5,436	$ 36,159	$ 37,282	0	5,436	$ 18,910
Inventory Write-down	0	$ 300	$ 0	$ 6,695	1,100	$ 17,495	$ 5,785
City Living [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Inventory Write-down					0				4,800
North [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Inventory Write-down	1,106				212			1,478	17,860
South [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Inventory Write-down	630				3,072			2,619	7,418
Mid-Atlantic [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Inventory Write-down	4,783				1,277			15,449	1,380
Pacific [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Inventory Write-down	$ 4				$ 31			$ 1,961	$ 76