Income Taxes (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Unrecognized tax benefits, excluding interest and penalties
Gross unrecognized tax benefits balance at beginning of year	$ 70.3	$ 75.1	$ 66.3
Additions based on tax positions related to the current year	1.1	0	22.3
Additions based on tax positions related to prior years	8.8	3.3	9.3
Reductions based on tax positions related to prior years	0	0	(0.6)
Reductions related to settlements with taxing authorities	(36.2)	(6.3)	(18.5)
Reductions related to lapses of statute of limitations	(1.2)	(2.4)	(3.0)
Effect of foreign currency translation	(2.0)	0.6	(0.7)
Gross unrecognized tax benefits balance at end of year	$ 40.8	$ 70.3	$ 75.1