Intangible Assets - Gross and Net Intangible Assets by Major Class (Details) - USD ($) $ in Millions	9 Months Ended
	Jun. 30, 2015	Sep. 30, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 3.0
Finite-Lived Intangible Assets, Gross	18.1	$ 15.1
Finite-Lived Intangible Assets, Accumulated Amortization	(6.8)	(5.7)
Finite-Lived Intangible Assets, Net	11.3	9.4
Computer Software, Intangible Asset [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Computer Software, Gross	3.7	2.2
Finite-Lived Intangible Assets, Accumulated Amortization	(2.2)	(1.9)
Finite-Lived Intangible Assets, Net	1.5	0.3
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Customer Lists, Gross	14.4	12.9
Finite-Lived Intangible Assets, Accumulated Amortization	(4.6)	(3.8)
Finite-Lived Intangible Assets, Net	$ 9.8	$ 9.1