Fair Value Measurements (Details) (USD $) In Millions	Sep. 30, 2011	Sep. 30, 2010
Fair value balance sheet items measured on a recurring basis
Marketable securities, available-for-sale	$ 297.6	$ 297.7
Mortgage loans held for sale	294.1	253.8
Homebuilding [Member]
Fair value balance sheet items measured on a recurring basis
Marketable securities, available-for-sale	297.6	297.7
Homebuilding [Member] \| Level 1 [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Marketable securities, available-for-sale	16.3	1.0
Homebuilding [Member] \| Level 2 [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Marketable securities, available-for-sale	281.3	296.7
Homebuilding [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Marketable securities, available-for-sale	297.6	297.7
Financial Services [Member]
Fair value balance sheet items measured on a recurring basis
Mortgage loans held for sale	294.1	253.8
Financial Services [Member] \| Interest Rate Lock Commitments [Member] \| Level 1 [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Fair value of interest rate derivatives	0	0
Financial Services [Member] \| Interest Rate Lock Commitments [Member] \| Level 2 [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Fair value of interest rate derivatives	3.9	1.8
Financial Services [Member] \| Interest Rate Lock Commitments [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Fair value of interest rate derivatives	3.9	1.8
Financial Services [Member] \| Best-Efforts Delivery Commitments [Member] \| Level 1 [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Fair value of interest rate derivatives	0	0
Financial Services [Member] \| Best-Efforts Delivery Commitments [Member] \| Level 2 [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Fair value of interest rate derivatives	(0.9)	0.2
Financial Services [Member] \| Best-Efforts Delivery Commitments [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Fair value of interest rate derivatives	(0.9)	0.2
Financial Services [Member] \| Hedging Instruments Related to IRLCs [Member] \| Level 1 [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Fair value of interest rate derivatives	0	0
Financial Services [Member] \| Hedging Instruments Related to IRLCs [Member] \| Level 2 [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Fair value of interest rate derivatives	(4.0)	(1.8)
Financial Services [Member] \| Hedging Instruments Related to IRLCs [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Fair value of interest rate derivatives	(4.0)	(1.8)
Financial Services [Member] \| Level 1 [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Mortgage loans held for sale	0	0
Financial Services [Member] \| Level 2 [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Mortgage loans held for sale	294.1	253.8
Financial Services [Member] \| Fair Value Measurements, Recurring [Member]
Fair value balance sheet items measured on a recurring basis
Mortgage loans held for sale	$ 294.1	$ 253.8

For an unclassified balance sheet, total of debt securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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+ Details