Fair Value Disclosures (Level 4 inventory fv) (Details 3) $ in Thousands	3 Months Ended					12 Months Ended
	Jan. 31, 2019 USD ($)	Oct. 31, 2018 USD ($)	Jul. 31, 2018 USD ($)	Apr. 30, 2018 USD ($)	Jan. 31, 2018 USD ($)	Oct. 31, 2018 USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Inventory Write-down	$ 7,562				$ 3,853
Operating communities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Inventory Write-down	$ 5,785					$ 30,151
Fair Value, Measurements, 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)	49	43	55	65	64
Number of Communities Impaired (in ones)	5	6	5	4	5
Fair Value Of Communities Net Of Impairment Charges	$ 37,282	$ 24,692	$ 43,063	$ 21,811	$ 13,318	$ 24,692
Inventory Write-down	$ 5,785	$ 4,025	$ 9,065	$ 13,325	$ 3,736
City Living [Member] | Fair Value, Measurements, 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	$ 2,800
North [Member] | Fair Value, Measurements, 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)	3			1
Inventory Write-down	$ 1,500			$ 12,000
South [Member] | Fair Value, Measurements, 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	$ 1,500
Mid-Atlantic [Member] | Fair Value, Measurements, 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
Inventory Write-down			$ 7,300