Acquisition (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended	72 Months Ended	120 Months Ended
	Dec. 31, 2012	Nov. 01, 2016	Nov. 01, 2020	Dec. 31, 2011	Dec. 31, 2010	Nov. 03, 2010
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired						100.00%
Business Acquisition, Cost of Acquired Entity, Purchase Price						$ 23.9
Business Acquisition, Preacquisition Contingency, Amount						1.3
Business Acquisition, Contingent Consideration, Potential Cash Payment				3.4		30.0
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	12.5			12.5	5.0
Business Acquisition, Purchase Price Allocation, Goodwill Amount						18.9
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets					8.4
Finite-Lived Intangible Asset, Useful Life		6 years	10 years
Business Acquisition, Purchase Price Allocation, Current Liabilities, Deferred Revenue						4.0
Business Acquisition, Contingent Consideration, at Fair Value						1.6
Business Acquisition, Purchase Price Allocation, Liabilities Assumed						0.9
Goodwill, Impairment Loss	16.4
Impairment of Intangible Assets (Excluding Goodwill)	6.4
Contingent Consideration Type [Domain]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	$ 2.5			$ 2.5
Weighted Average [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life			7 years 4 months 24 days