Fair Value Measurements and Risk - Gain (Loss) on Nonderivative Instrument (Details) - Net Investment Hedging - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 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	(200,000)	100,000	(4,400,000)
Currency Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	8,100,000	(2,900,000)	12,400,000	(900,000)
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	$ (200,000)	$ 100,000	$ 0