Revenue (Summary of Receivables and Contract Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Accounts receivable, net of allowances of $51.1 and $66.6	$ 259.1	$ 280.2
Allowances	51.1	66.6
Contract liabilities	$ 52.1	$ 51.0

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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