Valuation and Qualifying Accounts and Reserves (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Allowance for doubtful accounts receivable [Member]
Valuation and Qualifying Accounts [Rollfoward]
Balance at Beginning of Year	$ 3.6	$ 5.1	$ 4.0
Additions/(Reversals) Charged to Costs and Expenses	0.1	(0.2)	2.1
Deductions	(0.7)	(1.3)	(1.0)
Balance at End of Year	3.0	3.6	5.1
Allowance for credit memos and returns [Member]
Valuation and Qualifying Accounts [Rollfoward]
Balance at Beginning of Year	18.6	18.6	16.8
Additions/(Reversals) Charged to Costs and Expenses	118.3	102.3	85.4
Deductions	(116.5)	(102.3)	(83.6)
Balance at End of Year	20.4	18.6	18.6
Valuation allowance on deferred tax asset [Member]
Valuation and Qualifying Accounts [Rollfoward]
Balance at Beginning of Year	2.6	2.2	2.5
Additions/(Reversals) Charged to Costs and Expenses	0.6	0.4
Deductions			(0.3)
Balance at End of Year	$ 3.2	$ 2.6	$ 2.2