Acquisition Acquisition (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired		$ 4.9
Goodwill, Acquired During Period	0.7
Business Acquisition, Purchase Price Allocation, Goodwill Amount	8.6
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets	12.4
Business Acquisition, Contingent Consideration, at Fair Value	4.1	3.9
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	11.1
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets	8.7
Service Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets	$ 3.7