Inventory - Results of Discounted Cash Flow Analysis (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2017 USD ($) lot Community	Sep. 30, 2016 USD ($) lot Community
Real Estate, Write-down or Reserve [Line Items]
Number of Communities Impaired | Community	1	3
Number of Lots Impaired | lot	46	291
Impairment Charge	$ 1,693	$ 13,724
Estimated Fair Value of Impaired Inventory at time of Impairment	$ 3,791	$ 34,418
Corporate and unallocated | Continuing Operations
Real Estate, Write-down or Reserve [Line Items]
Number of Communities Impaired | Community	0	0
Number of Lots Impaired | lot	0	0
Impairment Charge	$ 68	$ 1,101
Estimated Fair Value of Impaired Inventory at time of Impairment	$ 0	$ 0
West | Operating Segments | Continuing Operations
Real Estate, Write-down or Reserve [Line Items]
Number of Communities Impaired | Community	1	2
Number of Lots Impaired | lot	46	213
Impairment Charge	$ 1,625	$ 6,729
Estimated Fair Value of Impaired Inventory at time of Impairment	$ 3,791	$ 16,345
East | Operating Segments | Continuing Operations
Real Estate, Write-down or Reserve [Line Items]
Number of Communities Impaired | Community		1
Number of Lots Impaired | lot		78
Impairment Charge		$ 5,894
Estimated Fair Value of Impaired Inventory at time of Impairment		$ 18,073