Income Taxes (Details 2) (USD $) In Millions	Sep. 30, 2011	Sep. 30, 2010
Deferred tax assets:
Inventory costs	$ 66.3	$ 105.6
Inventory impairments	387.3	449.2
Warranty and construction defect costs	111.4	107.2
Net operating loss carryforwards	238.2	183.6
Tax credit carryforwards	3.2	1.0
Incentive compensation plans	51.4	45.9
Deferral of profit on home sales	0.6	0.8
Goodwill impairment	3.4	8.9
Other	34.3	48.1
Total deferred tax assets	896.1	950.3
Valuation allowance	(848.5)	(902.6)
Total deferred tax assets, net of valuation allowance	47.6	47.7
Deferred tax liabilities	47.6	47.7
Deferred income taxes, net	$ 0	$ 0