Summary of Significant Accounting Policies (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) segment	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Pre-tax loss from foreign currency remeasurements	$ (19.9)		$ (15.1)
Pre-tax gain from foreign currency remeasurements		$ 15.0
Number of reportable segments | segment	2
Allowance for doubtful accounts receivable	$ 4.0	4.1
Repossessed inventory	20.2	19.6
Other inventories	247.6	234.9
Research and development expenses	191.6	175.2	172.3
Advertising costs	144.3	135.5	137.4
Total share-based award compensation expense	35.5	32.5	32.3
Total share-based award compensation expense, net of taxes	$ 27.2	$ 20.5	$ 20.4
Buildings
Property, Plant and Equipment [Line Items]
Useful lives of property, plant and equipment (in years)	30 years
Building Equipment and Land Improvements
Property, Plant and Equipment [Line Items]
Useful lives of property, plant and equipment (in years)	7 years
Machinery and equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful lives of property, plant and equipment (in years)	3 years
Machinery and equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful lives of property, plant and equipment (in years)	10 years
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Useful lives of property, plant and equipment (in years)	5 years
Software | Minimum
Property, Plant and Equipment [Line Items]
Useful lives of property, plant and equipment (in years)	3 years
Software | Maximum
Property, Plant and Equipment [Line Items]
Useful lives of property, plant and equipment (in years)	7 years