Inventory - Inventory Impairments and Lot Option Abandonment Charges, by Reportable Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Real Estate, Write-down or Reserve [Line Items]
Land Held for Sale	$ 5,900	$ 600	$ 800
Total impairment and abandonment charges	6,949	2,445	15,282
Continuing Operations
Real Estate, Write-down or Reserve [Line Items]
Projects in progress	1,005	1,693	13,724
Land Held for Sale	5,494	564	770
Abandonments	0	188	788
Total impairment and abandonment charges	6,499	2,445	15,282
Total impairment and abandonment charges	6,949	2,445	15,282
Continuing Operations | Corporate and unallocated
Real Estate, Write-down or Reserve [Line Items]
Projects in progress	212	68	1,101
Land Held for Sale	2,108	0	0
Continuing Operations | West
Real Estate, Write-down or Reserve [Line Items]
Projects in progress	0	1,625	6,729
Land Held for Sale	0	94	119
Continuing Operations | East
Real Estate, Write-down or Reserve [Line Items]
Projects in progress	0	0	5,894
Land Held for Sale	168	470	280
Abandonments	0	188	0
Continuing Operations | Southeast
Real Estate, Write-down or Reserve [Line Items]
Projects in progress	793	0	0
Land Held for Sale	3,218	0	371
Abandonments	0	0	788
Discontinued Operations
Real Estate, Write-down or Reserve [Line Items]
Land Held for Sale	450	0	0
Total impairment and abandonment charges	$ 450	$ 0	$ 0