Fair Value Measurements and Risk - Gain (Loss) on Nonderivative Instrument (Details) - Net Investment Hedging - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ 0	$ 0	$ 0	$ 0
Non-derivatives in ASC 815 net investment hedging relationships:	0	1,900,000	100,000	(4,200,000)
Currency Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	500,000	13,300,000	4,300,000	2,000,000.0
Foreign currency denominated debt
Derivative Instruments, Gain (Loss) [Line Items]
Non-derivatives in ASC 815 net investment hedging relationships:	0	0	0	(4,400,000)
Foreign currency denominated deferred intercompany royalties
Derivative Instruments, Gain (Loss) [Line Items]
Non-derivatives in ASC 815 net investment hedging relationships:	$ 0	$ 1,900,000	$ 100,000	$ 200,000