Fair Value Measurements and Risk Fair Value Measurement and Risk - Gain (Loss) on Derivatives and Non-derivatives Designated as Net Investment Hedges (Details 4) - Net Investment Hedging [Member] - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Gains and losses on derivative instruments
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ 0	$ 0	$ 0
Amount of Gain (Loss) Recognized in OCI in Currency Translation Adjustments	(3,900,000)	(17,700,000)	7,100,000
Foreign currency denominated debt [Member]
Gains and losses on derivative instruments
Amount of Gain (Loss) Recognized in OCI in Currency Translation Adjustments	(4,400,000)	(11,200,000)	4,600,000
Currency Swap [Member]
Gains and losses on derivative instruments
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), before Reclassification and Tax	6,000,000	(21,900,000)	5,600,000
Foreign currency denominated deferred intercompany royalties [Member]
Gains and losses on derivative instruments
Amount of Gain (Loss) Recognized in OCI in Currency Translation Adjustments	$ 500,000	$ (6,500,000)	$ 2,500,000