Fair Value Measurements Fair Value Measurements - Level 3 Rollforward (Details) (USD $) In Millions, unless otherwise specified													3 Months Ended
	Dec. 31, 2013 Homebuilding [Member]	Sep. 30, 2013 Homebuilding [Member]	Dec. 31, 2013 Homebuilding [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]		Sep. 30, 2013 Homebuilding [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]		Dec. 31, 2013 Financial Services [Member]	Sep. 30, 2013 Financial Services [Member]	Dec. 31, 2013 Financial Services [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]		Sep. 30, 2013 Financial Services [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]		Dec. 31, 2013 Debt Securities [Member]	Dec. 31, 2013 Debt Securities [Member] Homebuilding [Member]	Dec. 31, 2013 Residential Real Estate [Member]	Dec. 31, 2013 Loans Receivable [Member] Financial Services [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Discount Rate													6.00%		18.00%
Other Investments	$ 20.3	$ 20.3	$ 20.3	[1]	$ 20.3	[1]
Mortgage loans held for sale							299.8	395.1	5.9	[2]	5.7	[2]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings, Description														0		0.1	[2]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases														0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements														0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales																(0.2)	[2]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3																$ 0.3	[2]

[1] In October 2012, the Company purchased defaulted debt securities which are secured by residential real estate. The Company intends to foreclose on the property or negotiate an agreement to obtain the right to take possession of the residential real estate in order to develop the property and ultimately build and sell homes. These securities, which are included in other assets in the consolidated balance sheets, are classified as available for sale and are reflected at fair value. The fair value of these securities was determined by estimating the future cash flows of the securities and the residential real estate utilizing discount rates of 6% and 18%, respectively. Unrealized gains or losses on these securities, net of tax, are recorded in accumulated other comprehensive income (loss) in the consolidated balance sheets.

[2] Mortgage loans held for sale are reflected at fair value. Interest income earned on mortgage loans held for sale is based on contractual interest rates and included in financial services interest and other income. Mortgage loans held for sale at December 31, 2013 includes $5.9 million of originated loans for which the Company elected the fair value option upon origination and for which the Company has not sold into the secondary market, but plans to sell as market conditions permit. The fair value of these mortgage loans held for sale is generally calculated considering the secondary market and adjusted for the value of the underlying collateral, including interest rate risk, liquidity risk and prepayment risk.