Inventory - Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2015 home	Mar. 31, 2014 property	Mar. 31, 2015 home	Mar. 31, 2014 property	Sep. 30, 2014 home
Real Estate Properties [Line Items]
Number of substantially completed homes unsold	115		115		205
Total value of substantially completed homes	$ 29.3		$ 29.3		$ 48.0
Threshold number of homes below a minimum threshold of profitability	10		10
Number of Communities on Watch List	1	4	1	4
Southeast Segment
Real Estate Properties [Line Items]
Number of Communities on Watch List		2