Other Assets and Accrued Expenses and Other Liabilities (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013
Homebuilding other assets
Homebuilding other assets	$ 514.2		$ 502.7
Homebuilding [Member]
Homebuilding other assets
Insurance receivables	134.1		138.4	136.1
Earnest money and refundable deposits	121.0		113.3
Accounts and notes receivable	43.0		38.6
Prepaid assets	51.5		55.4
Rental Properties	48.6		48.7
Other Investments	20.8		20.8
Other assets	23.4		25.9
Homebuilding other assets	442.4		441.1
Homebuilding accrued expenses and other liabilities
Construction defect and other litigation liabilities	449.4		456.9	454.2		482.0
Employee compensation and related liabilities	144.2		150.8
Warranty liability	71.6	65.9	65.7	57.3	56.7	56.9
Accrued interest	31.0		29.1
Federal and state income tax liabilities	6.6		12.8
Construction Payable	29.7		36.1
Customer Deposits, Current	54.8		49.5
Accrual for Taxes Other than Income Taxes, Current	17.5		29.1
Other liabilities	42.9		45.0
Homebuilding accrued expenses and other liabilities	$ 847.7		$ 875.0