Accounts Receivable (Components Of Finance And Contract Receivables Beyond One Year) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables, net of unearned finance charges of $9.9 million and $9.4 million	$ 461.5	$ 447.9
Contract receivables, net of unearned finance charges of $15.3 million and $12.1 million	174.3	167.7
Total noncurrent finance and contract receivables	635.8	615.6
Allowances for doubtful accounts: Finance receivables	(16.3)	(16.1)
Allowances for doubtful accounts: Contract receivables	(2.8)	(2.6)
Allowances for doubtful accounts: Total	(19.1)	(18.7)
Total long-term finance and contract receivables - net	616.7	596.9
Finance receivables - net	445.2	431.8
Contract receivables - net	171.5	165.1
Non Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unearned finance charges, finance receivables	9.9	9.4
Unearned finance charges, contract receivables	$ 15.3	$ 12.1