Notes Payable (Details) - USD ($) $ in Millions	Jun. 30, 2015	Sep. 30, 2014
Unsecured:
Notes payable	$ 3,821.1	$ 3,682.8
Homebuilding [Member]
Unsecured:
Notes payable	3,373.1	3,323.6
Financial Services [Member]
Unsecured:
Assets Sold under Agreements to Repurchase, Repurchase Liability	$ 448.0	359.2
Senior Note Seven [Member] \| Homebuilding [Member]
Unsecured:
Stated interest rate	5.25%
Senior Note Twenty Six [Member] \| Homebuilding [Member]
Unsecured:
Stated interest rate	3.625%
Senior Note Eight [Member] \| Homebuilding [Member]
Unsecured:
Stated interest rate	5.625%
Senior Note Nine [Member] \| Homebuilding [Member]
Unsecured:
Stated interest rate	6.50%
Senior Note Twenty Four [Member] \| Homebuilding [Member]
Unsecured:
Stated interest rate	4.75%
Senior Note Twenty Nine [Member] \| Homebuilding [Member]
Unsecured:
Stated interest rate	3.75%
Senior Note Member Thirty [Member] \| Homebuilding [Member]
Unsecured:
Stated interest rate	4.00%
Senior Note Member Twenty Five [Member] \| Homebuilding [Member]
Unsecured:
Stated interest rate	4.375%
Senior Note Twenty Seven [Member] \| Homebuilding [Member]
Unsecured:
Stated interest rate	4.75%
SeniorNoteTwentyEight [Member] \| Homebuilding [Member]
Unsecured:
Stated interest rate	5.75%
Unsecured Debt [Member] \| Senior Note Seven [Member] \| Homebuilding [Member]
Unsecured:
Notes payable	$ 0.0	157.7
Unsecured Debt [Member] \| Senior Note Twenty Six [Member] \| Homebuilding [Member]
Unsecured:
Notes payable	400.0	400.0
Unsecured Debt [Member] \| Senior Note Eight [Member] \| Homebuilding [Member]
Unsecured:
Notes payable	170.0	169.9
Unsecured Debt [Member] \| Senior Note Nine [Member] \| Homebuilding [Member]
Unsecured:
Notes payable	372.7	372.6
Unsecured Debt [Member] \| Senior Note Twenty Four [Member] \| Homebuilding [Member]
Unsecured:
Notes payable	350.0	350.0
Unsecured Debt [Member] \| Senior Note Twenty Nine [Member] \| Homebuilding [Member]
Unsecured:
Notes payable	500.0	500.0
Unsecured Debt [Member] \| Senior Note Member Thirty [Member] \| Homebuilding [Member]
Unsecured:
Notes payable	500.0	0.0
Unsecured Debt [Member] \| Senior Note Member Twenty Five [Member] \| Homebuilding [Member]
Unsecured:
Notes payable	350.0	350.0
Unsecured Debt [Member] \| Senior Note Twenty Seven [Member] \| Homebuilding [Member]
Unsecured:
Notes payable	300.0	300.0
Unsecured Debt [Member] \| SeniorNoteTwentyEight [Member] \| Homebuilding [Member]
Unsecured:
Notes payable	400.0	400.0
Line of Credit [Member] \| Homebuilding [Member]
Unsecured:
Line of Credit Facility, Amount Outstanding	0.0	300.0
Secured Debt [Member] \| Homebuilding [Member]
Unsecured:
Notes payable	$ 30.4	$ 23.4

Amount to be repaid to the counterparty to the repurchase agreement when the carrying amount (or market value, if higher than the carrying amount) of securities or other assets sold under the repurchase agreement exceeds 10 percent of total assets.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(m)(1)(i)(A)(ii))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

+ Details

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- Definition

Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- References

No definition available.

+ Details

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