Inventory - Narrative (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Jun. 30, 2016 home	Sep. 30, 2016 USD ($) home Community	Sep. 30, 2016 USD ($) home lot Community	Sep. 30, 2016 USD ($) home Community	Sep. 30, 2016 USD ($) home Community	Sep. 30, 2015 USD ($) home Community	Sep. 30, 2014 USD ($) lot Community
Real Estate Properties [Line Items]
Number of substantially completed homes not subject to a sales contract | home		178	178	178	178	128
Total value of substantially completed homes		$ 56,100	$ 56,100	$ 56,100	$ 56,100	$ 40,100
Threshold number of homes below a minimum threshold of profitability	10	10	10
Number of watch list communities requiring further analysis | Community				7		0	4
Impairment charge					$ 13,724		$ 5,321
Number of communities remaining on watch list | Community		6	6	6	6
Impairment of projects in process					$ 13,700		$ 5,400
East
Real Estate Properties [Line Items]
Number of watch list communities requiring further analysis | Community				1			0
East | Discontinued Operations
Real Estate Properties [Line Items]
Threshold number of homes below a minimum threshold of profitability | lot							10
Impairment of projects in process							$ 100