Schedule II (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Beginning Balance	$ 1.9	$ 2.4	$ 3.2
Valuation Allowances and Reserves, Charged to Cost and Expense	5.8	2.6	3.1
Valuation Allowances and Reserves, Deductions	3.9	3.1	3.9
Valuation Allowances and Reserves, Ending Balance	$ 3.8	$ 1.9	$ 2.4