Income Taxes (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Unrecognized tax benefits
Unrecognized tax benefits, beginning of year	$ 4.2	$ 14.1	$ 16.3
Reductions attributable to tax positions taken in prior years	(4.2)	(2.4)	(1.6)
Reductions attributable to lapse of statue of limitations	0	(7.5)	(0.6)
Unrecognized tax benefits, end of year	$ 0	$ 4.2	$ 14.1