Inventory - Narrative (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2016 USD ($) home lot Community	Mar. 31, 2015 USD ($) property	Mar. 31, 2016 USD ($) home lot Community	Mar. 31, 2015 USD ($)	Sep. 30, 2015 USD ($) home
Real Estate Properties [Line Items]
Threshold Number of Homes Below a Minimum Threshold of Profitability | home			10
Discounted Cash Flow Analyses, Number of Lots Impaired | lot	34		34
Number of substantially completed homes unsold | home	117		117		128
Total value of substantially completed homes	$ 33,100		$ 33,100		$ 40,100
Number of Communities on Watch List	2	2
Undiscounted Cash Flow Analysis Prepared for Number of Communities	2	2
Impairment Charge	$ 1,825		1,825
Inventory Impairment and Abandonment	$ 1,825	$ 0	$ 3,181	$ 0
Discounted Cash Flow Analyses, Number of Impaired Communities	1	1	1