Intangible Assets - Gross and Net Intangible Assets by Major Class (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Trade Names, Gross		$ 0.1
Finite-Lived Intangible Assets, Gross	19.0	16.2
Finite-Lived Intangible Assets, Accumulated Amortization	(8.5)	(6.3)
Finite-Lived Intangible Assets, Net	10.5	9.9
Goodwill	47.5	44.7
Gross Finite and Indefinite-Lived Intangible Assets	20.1	17.4
Finite and Indefinited-Lived Accumulated Amortization and Impairment Charges	(8.5)	(6.3)
Intangible Assets, Net (Excluding Goodwill)	11.6	11.1
Noncompete Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Noncompete Agreements, Gross	3.7	3.7
Finite-Lived Intangible Assets, Accumulated Amortization	(3.7)	(3.0)
Finite-Lived Intangible Assets, Net	0	0.7
Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Trade Names, Gross	0.7	0.7
Finite-Lived Intangible Assets, Accumulated Amortization	(0.7)	(0.5)
Finite-Lived Intangible Assets, Net	0	0.2
Computer Software, Intangible Asset [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Computer Software, Gross	2.2	2.2
Finite-Lived Intangible Assets, Accumulated Amortization	(1.5)	(1.0)
Finite-Lived Intangible Assets, Net	0.7	1.2
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Customer Lists, Gross	12.4	9.6
Finite-Lived Intangible Assets, Accumulated Amortization	(2.6)	(1.8)
Finite-Lived Intangible Assets, Net	$ 9.8	$ 7.8