Revenue (Narrative) (Details) - Sales returns, rebates, and discounts	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Change in Accounting Estimate [Line Items]
Revenue, information used to determine revenue recognized, change in accounting estimate, percent	3.00%
U.S.
Change in Accounting Estimate [Line Items]
Revenue, information used to determine revenue recognized, change in accounting estimate, percent		4.00%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration