Other Assets and Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2014
Homebuilding other assets
Homebuilding other assets	$ 531.9		$ 530.2
Homebuilding [Member]
Homebuilding other assets
Insurance receivables	97.5		126.5	$ 129.6
Earnest money and refundable deposits	194.2		137.2
Accounts and notes receivable	34.2		49.2
Prepaid assets	25.7		40.9
Rental properties	54.6		47.1
Debt securities collateralized by residential real estate	0.0		33.9
Other assets	16.6		21.4
Homebuilding other assets	422.8		456.2
Homebuilding accrued expenses and other liabilities
Reserves for legal claims	426.4		451.0	450.7		$ 456.9
Employee compensation and related liabilities	159.7		172.7
Warranty liability	93.7	$ 87.9	82.0	$ 77.4	$ 71.6	$ 65.7
Accrued interest	40.1		30.7
Federal and state income tax liabilities	35.5		36.1
Inventory related accruals	28.8		30.0
Homebuyer deposits	67.5		58.9
Accrued property taxes	22.8		32.0
Other liabilities	35.3		35.8
Homebuilding accrued expenses and other liabilities	$ 909.8		$ 929.2