Inventory - Results of Discounted Cash Flow Analysis (Details) $ in Thousands	9 Months Ended
	Jun. 30, 2019 USD ($) lot Community
Real Estate, Write-down or Reserve [Line Items]
Number of Communities Impaired | Community	10
Number of Lots Impaired | lot	854
Impairment Charge	$ 110,030
Estimated Fair Value of Impaired Inventory at time of Impairment	$ 84,982
Continuing Operations | West Segment
Real Estate, Write-down or Reserve [Line Items]
Number of Communities Impaired | Community	9
Number of Lots Impaired | lot	839
Impairment Charge	$ 92,912
Estimated Fair Value of Impaired Inventory at time of Impairment	$ 69,449
Continuing Operations | Southeast Segment
Real Estate, Write-down or Reserve [Line Items]
Number of Communities Impaired | Community	1
Number of Lots Impaired | lot	15
Impairment Charge	$ 858
Estimated Fair Value of Impaired Inventory at time of Impairment	$ 1,367
Corporate and unallocated | Continuing Operations
Real Estate, Write-down or Reserve [Line Items]
Number of Communities Impaired | Community	0
Number of Lots Impaired | lot	0
Impairment Charge	$ 16,260
Estimated Fair Value of Impaired Inventory at time of Impairment	$ 14,166