Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013
Homebuilding [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Investments	$ 20.8		$ 20.3
Financial Services [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Mortgage loans held for sale	476.9		395.1
Recurring [Member] | Level 1 [Member] | Homebuilding [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Investments	0	[1]	0	[1]
Recurring [Member] | Level 1 [Member] | Financial Services [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Mortgage loans held for sale	0	[2]	0	[2]
Recurring [Member] | Level 1 [Member] | Financial Services [Member] | Interest rate lock commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Fair value of interest rate derivatives	0	[3]	0	[3]
Recurring [Member] | Level 1 [Member] | Financial Services [Member] | Forward Sales Of MBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Fair value of interest rate derivatives	0	[3]	0	[3]
Recurring [Member] | Level 1 [Member] | Financial Services [Member] | Best-efforts and mandatory commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Fair value of interest rate derivatives	0	[3]	0	[3]
Recurring [Member] | Level 2 [Member] | Homebuilding [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Investments	0	[1]	0	[1]
Recurring [Member] | Level 2 [Member] | Financial Services [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Mortgage loans held for sale	464.9	[2]	389.4	[2]
Recurring [Member] | Level 2 [Member] | Financial Services [Member] | Interest rate lock commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Fair value of interest rate derivatives	2.4	[3]	7.0	[3]
Recurring [Member] | Level 2 [Member] | Financial Services [Member] | Forward Sales Of MBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Fair value of interest rate derivatives	(1.9)	[3]	(8.8)	[3]
Recurring [Member] | Level 2 [Member] | Financial Services [Member] | Best-efforts and mandatory commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Fair value of interest rate derivatives	(0.1)	[3]	(3.1)	[3]
Recurring [Member] | Level 3 [Member] | Homebuilding [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Investments	20.8	[1]	20.3	[1]
Recurring [Member] | Level 3 [Member] | Financial Services [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Mortgage loans held for sale	12.0	[2]	5.7	[2]
Recurring [Member] | Level 3 [Member] | Financial Services [Member] | Interest rate lock commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Fair value of interest rate derivatives	0		0	[3]
Recurring [Member] | Level 3 [Member] | Financial Services [Member] | Forward Sales Of MBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Fair value of interest rate derivatives	0		0	[3]
Recurring [Member] | Level 3 [Member] | Financial Services [Member] | Best-efforts and mandatory commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Fair value of interest rate derivatives	0		0	[3]
Recurring [Member] | Estimate fair value [Member] | Homebuilding [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Investments	20.8	[1]	20.3	[1]
Recurring [Member] | Estimate fair value [Member] | Financial Services [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Mortgage loans held for sale	476.9	[2]	395.1	[2]
Recurring [Member] | Estimate fair value [Member] | Financial Services [Member] | Interest rate lock commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Fair value of interest rate derivatives	2.4	[3]	7.0
Recurring [Member] | Estimate fair value [Member] | Financial Services [Member] | Forward Sales Of MBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Fair value of interest rate derivatives	(1.9)	[3]	(8.8)
Recurring [Member] | Estimate fair value [Member] | Financial Services [Member] | Best-efforts and mandatory commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Fair value of interest rate derivatives	$ (0.1)	[3]	$ (3.1)

[1] In October 2012, the Company purchased defaulted debt securities which are secured by residential real estate. The Company intends to 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 September 30, 2014 includes $12.0 million of originated loans for which the Company elected the fair value option upon origination and 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.

[3] Fair value measurements of these derivatives represent changes in fair value and are reflected in the balance sheet. Changes in these fair values during the periods presented are included in financial services revenues in the consolidated statements of operations.