Inventory - Summary of Interests in Lot Option Agreements (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013
Real Estate Properties [Line Items]
Deposits and non-refundable preacquisition costs incurred	$ 47,067	$ 37,313
Remaining obligations	378,495	288,638
Land not owned under option agreements	7,751	9,124
Consolidated VIEs
Real Estate Properties [Line Items]
Deposits and non-refundable preacquisition costs incurred	4,604	4,491
Remaining obligations	3,147	4,633
Land not owned under option agreements	7,751	9,124
Unconsolidated lot option agreements
Real Estate Properties [Line Items]
Deposits and non-refundable preacquisition costs incurred	42,463	32,822
Remaining obligations	375,348	284,005
Land not owned under option agreements	$ 0	$ 0