Basis of Presentation (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended					3 Months Ended		3 Months Ended
	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Homebuilding [Member]	Jun. 30, 2014 Homebuilding [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Sep. 30, 2013 Homebuilding [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2013 RegentHomes [Member]	Oct. 31, 2013 RegentHomes [Member] Lot Home	Jun. 30, 2014 Crown Communities [Member]	May 31, 2014 Crown Communities [Member] Lot Home
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired		$ 222.7	$ 9.4				$ 34.5		$ 209.6
Accrual for holdback payment related to acquisition		21.4	0
Business Acquisition, Number of Homes Acquired								240		640
Business Acquisition, Number of Finished Lots Acquired								300		2,350
Business Acquisition, Number of Lots Under Option Contracts								600		3,400
Business Acquisition, Sales Order Backlog Acquired (Homes)								213		431
Business Acquisition, Number of Homes Closed	254
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual	65.8
Goodwill, Acquired During Period									53.6
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory	140.5	140.5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	1.9	1.9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets	4.9	4.9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	11.7	11.7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	(3.0)	(3.0)
Business Information [Line Items]
Earnest Money Deposits				$ 47.0	$ 44.0	$ 36.9