Revenue Recognition and Accounts Receivable (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Revenue Recognition And Accounts Receivable [Line Items]
Sales allowances, current	$ 1,640.0	$ 1,980.0
Accrued sales allowances and other adjustments	631.9	818.0
Total Current Allowances	2,274.1	2,795.2
Securitized accounts receivable	464.0	$ 1,040.0
Receivables Facility
Revenue Recognition And Accounts Receivable [Line Items]
Accounts receivable securitization facility maximum borrowing capacity	$ 400.0