Inventory - Impairments and Lot Option Abandonment Charges, by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Real Estate, Write-down or Reserve [Line Items]
Impairment of inventory, projects in progress	$ 11,899	$ 0	$ 13,724	$ 0
Impairment of inventory, land held for sale	18	249	586	249
Total impairment and abandonment charges	11,917	249	15,098	249
Corporate and unallocated
Real Estate, Write-down or Reserve [Line Items]
Impairment of inventory, projects in progress	789	0	1,101	0
West Segment
Real Estate, Write-down or Reserve [Line Items]
Impairment of inventory, projects in progress	5,216	0	6,729	0
East Segment
Real Estate, Write-down or Reserve [Line Items]
Impairment of inventory, projects in progress	5,894	0	5,894	0
Impairment of inventory, land held for sale	18	249	215	249
Southeast Segment
Real Estate, Write-down or Reserve [Line Items]
Impairment of inventory, land held for sale	0	0	371	0
Abandonments	$ 0	$ 0	$ 788	$ 0