Fair Value Disclosures (Level 4 inventory fv) (Details 3) $ in Thousands	3 Months Ended					12 Months Ended
	Jan. 31, 2020 USD ($)	Oct. 31, 2019 USD ($)	Jul. 31, 2019 USD ($)	Apr. 30, 2019 USD ($)	Jan. 31, 2019 USD ($)	Oct. 31, 2019 USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Inventory Write-down	$ 1,031				$ 7,562
Operating communities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Inventory Write-down	$ 0					$ 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)	65	71	69	64	49
Number of Communities Impaired (in ones)	0	7	3	6	5
Fair Value Of Communities Net Of Impairment Charges	$ 0	$ 18,910	$ 5,436	$ 36,159	$ 37,282	$ 18,910
Inventory Write-down	$ 0	$ 6,695	$ 1,100	$ 17,495	$ 5,785
City Living [Member] | 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 Communities Impaired (in ones)				1	1
Inventory Write-down				$ 2,000	$ 2,800
North [Member] | 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 Communities Impaired (in ones)		4		4	3
Inventory Write-down		$ 5,100		$ 15,000	$ 1,500
South [Member] | 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 Communities Impaired (in ones)		2		1	1
Inventory Write-down		$ 600		$ 500	$ 1,500
Pacific [Member] | 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 Communities Impaired (in ones)		1
Inventory Write-down		$ 1,000