Inventory - Summary of Interests in Lot Option Agreements (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Sep. 30, 2013
Real Estate Properties [Line Items]
Deposits and non-refundable preacquisition costs incurred	$ 42,627	$ 37,313
Remaining obligations	417,233	288,638
Land not owned under option agreements	7,588	9,124
Consolidated VIEs
Real Estate Properties [Line Items]
Deposits and non-refundable preacquisition costs incurred	4,572	4,491
Remaining obligations	3,016	4,633
Land not owned under option agreements	7,588	9,124
Unconsolidated lot option agreements
Real Estate Properties [Line Items]
Deposits and non-refundable preacquisition costs incurred	38,055	32,822
Remaining obligations	414,217	284,005
Land not owned under option agreements	$ 0	$ 0