Inventory - Inventory Impairments and Lot Option Abandonment Charges, by Reportable Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Real Estate, Write-down or Reserve [Line Items]
Land Held for Sale	$ 600	$ 800	$ 1,400
Continuing Operations
Real Estate, Write-down or Reserve [Line Items]
Projects in progress	1,693	13,724	0
Land Held for Sale	564	770	1,433
Abandonments	188	788	1,676
Total impairment and abandonment charges	2,445	15,282	3,109
Continuing Operations | Corporate and unallocated
Real Estate, Write-down or Reserve [Line Items]
Projects in progress	68	1,101	0
Continuing Operations | West
Real Estate, Write-down or Reserve [Line Items]
Projects in progress	1,625	6,729	0
Land Held for Sale	94	119	0
Continuing Operations | East
Real Estate, Write-down or Reserve [Line Items]
Projects in progress	0	5,894	0
Land Held for Sale	470	280	1,433
Abandonments	188	0	1,676
Continuing Operations | Southeast
Real Estate, Write-down or Reserve [Line Items]
Land Held for Sale	0	371	0
Abandonments	$ 0	$ 788	$ 0