Other Assets and Accrued Expenses and Other Liabilities (Details) (USD $) In Millions	Jun. 30, 2011	Mar. 31, 2011	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Sep. 30, 2009
Homebuilding other assets
Insurance receivables	$ 214.2		$ 251.5
Homebuilding other assets	440.5		482.7
Homebuilding accrued expenses and other liabilities
Construction defect and other litigation liabilities	523.2		571.3
Warranty liability	41.0	43.8	46.2	49.2	49.6	59.6
Homebuilding [Member]
Homebuilding other assets
Insurance receivables	214.2		251.5
Accounts and notes receivable	20.5		18.5
Prepaid assets	17.9		28.9
Other assets	138.6		135.9
Homebuilding other assets	391.2		434.8
Homebuilding accrued expenses and other liabilities
Construction defect and other litigation liabilities	523.2		571.3
Employee compensation and related liabilities	82.8		90.4
Warranty liability	41.0		46.2
Accrued interest	27.1		39.8
Federal and state income tax liabilities	23.9		83.8
Other liabilities	114.4		125.7
Homebuilding accrued expenses and other liabilities	$ 812.4		$ 957.2