Inventory - Results of Discounted Cash Flow Analysis (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2016 USD ($) lot Community	Sep. 30, 2014 USD ($) lot Community
Real Estate, Write-down or Reserve [Line Items]
Number of Communities Impaired | Community	3	2
Number of Lots Impaired | lot	291	180
Impairment charge	$ 13,724	$ 5,321
Estimated Fair Value of Impaired Inventory at time of Impairment	$ 34,418	$ 14,379
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	$ 1,101	$ 373
Estimated Fair Value of Impaired Inventory at time of Impairment	$ 0	$ 0
West | Continuing Operations
Real Estate, Write-down or Reserve [Line Items]
Number of Communities Impaired | Community	2	2
Number of Lots Impaired | lot	213	180
Impairment charge	$ 6,729	$ 4,948
Estimated Fair Value of Impaired Inventory at time of Impairment	$ 16,345	$ 14,379
East | 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