Notes Payable (Details 1) (Homebuilding [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2011
6.875% senior notes due 2013 [Member]
Summary of unsecured homebuilding notes payable outstanding
Principal Amount	$ 171.7
Date Issued	April 2003
Date Due	May 01, 2013
Redeemable prior to Maturity	No
Effective interest rate	7.00%
6.125% senior notes due 2014, net [Member]
Summary of unsecured homebuilding notes payable outstanding
Principal Amount	145.9
Date Issued	July 2004
Date Due	Jan. 15, 2014
Redeemable prior to Maturity	No
Effective interest rate	6.30%
2% convertible senior notes due 2014, net [Member]
Summary of unsecured homebuilding notes payable outstanding
Principal Amount	500.0
Date Issued	May 2009
Date Due	May 15, 2014
Redeemable prior to Maturity	No
Effective interest rate	9.70%
5.625% senior notes due 2014, net [Member]
Summary of unsecured homebuilding notes payable outstanding
Principal Amount	137.9
Date Issued	September 2004
Date Due	Sep. 15, 2014
Redeemable prior to Maturity	No
Effective interest rate	5.80%
5.25% senior notes due 2015, net [Member]
Summary of unsecured homebuilding notes payable outstanding
Principal Amount	157.7
Date Issued	February 2005
Date Due	Feb. 15, 2015
Redeemable prior to Maturity	Yes
Effective interest rate	5.40%
5.625% senior notes due 2016, net [Member]
Summary of unsecured homebuilding notes payable outstanding
Principal Amount	170.2
Date Issued	December 2004
Date Due	Jan. 15, 2016
Redeemable prior to Maturity	Yes
Effective interest rate	5.80%
6.5% senior notes due 2016, net [Member]
Summary of unsecured homebuilding notes payable outstanding
Principal Amount	$ 383.5
Date Issued	April 2006
Date Due	Apr. 15, 2016
Redeemable prior to Maturity	Yes
Effective interest rate	6.60%