Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Millions	Jun. 30, 2015	Sep. 30, 2014
Statement of Financial Position [Abstract]
Valuation allowance for deferred income taxes	$ 30.1	$ 31.1
Preferred stock, par value	$ 0.1	$ 0.1
Preferred stock, shares authorized	30,000,000	30,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	373,936,373	371,786,765
Common stock, shares outstanding	366,736,302	364,586,694
Treasury stock, shares	7,200,071	7,200,071