Consolidated Balance Sheets (Parenthetical) (Unaudited) (USD $) In Millions, except Share data, unless otherwise specified	Jun. 30, 2012	Sep. 30, 2011
Valuation allowance for deferred income taxes	$ 78.4	$ 848.5
Preferred stock, par value	$ 0.1	$ 0.1
Preferred stock, shares authorized	30,000,000	30,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	326,363,223	323,243,170
Common stock, shares outstanding	319,163,152	316,043,099
Treasury stock, shares	7,200,071	7,200,071
Homebuilding
Valuation allowance for deferred income taxes	$ 78.4	$ 848.5