Other Assets and Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Homebuilding other assets
Homebuilding other assets	$ 511.5	$ 530.2
Homebuilding [Member]
Homebuilding other assets
Insurance receivables	127.8	126.5	$ 137.7
Earnest money and refundable deposits	143.3	137.2
Accounts and notes receivable	29.9	49.2
Prepaid assets	31.8	40.9
Rental properties	45.9	47.1
Debt securities collateralized by residential real estate	35.5	33.9
Other assets	20.1	21.4
Homebuilding other assets	434.3	456.2
Homebuilding accrued expenses and other liabilities
Reserves for legal claims	458.9	451.0	457.6	$ 456.9
Employee compensation and related liabilities	142.2	172.7
Warranty liability	84.1	82.0	$ 65.9	$ 65.7
Accrued interest	49.4	30.7
Federal and state income tax liabilities	65.1	36.1
Inventory related accruals	25.4	30.0
Homebuyer deposits	56.8	58.9
Accrued property taxes	23.7	32.0
Other liabilities	29.7	35.8
Homebuilding accrued expenses and other liabilities	$ 935.3	$ 929.2