Other Assets and Accrued Expenses and Other Liabilities (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Homebuilding other assets
Homebuilding other assets	$ 506.8	$ 502.7
Homebuilding [Member]
Homebuilding other assets
Insurance receivables	137.7	138.4	148.1
Earnest money and refundable deposits	124.8	113.3
Accounts and notes receivable	38.4	38.6
Prepaid assets	53.2	55.4
Rental Properties	49.2	48.7
Other Investments	20.8	20.8
Other assets	24.4	25.9
Homebuilding other assets	448.5	441.1
Homebuilding accrued expenses and other liabilities
Construction defect and other litigation liabilities	457.6	456.9	469.6	482.0
Employee compensation and related liabilities	129.5	150.8
Warranty liability	65.9	65.7	56.7	56.9
Accrued interest	44.8	29.1
Federal and state income tax liabilities	63.9	12.8
Construction Payable	34.8	36.1
Customer Deposits, Current	45.5	49.5
Accrual for Taxes Other than Income Taxes, Current	18.2	29.1
Other liabilities	43.3	45.0
Homebuilding accrued expenses and other liabilities	$ 903.5	$ 875.0