Debt Debt (Net Investment Hedge) (Details) - USD ($) $ in Millions			12 Months Ended
		Oct. 01, 2021	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Apr. 15, 2016
Debt Instrument [Line Items]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	[1]		$ (198.0)	$ (153.3)	$ (126.3)
3.75% Senior Exchange Notes due 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 300.0
Debt Instrument, Interest Rate, Stated Percentage						3.75%
Debt Instrument, Maturity Date		Oct. 01, 2021
Medium-term Notes [Member]
Debt Instrument [Line Items]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax			$ 28.0

[1] Includes foreign exchange (losses) gains of $(23.3) million, $(22.9) million and $(29.6) million during 2016, 2015 and 2014, respectively, associated with intercompany loans designated as long-term.