Derivative Instruments, Hedging Activities and Fair Value - Derivatives Designated as Hedging Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Derivative [Line Items]
Product Revenues	$ 447,288	$ 408,038
Interest Expense	(9,739)	(9,583)
Product Revenues | Interest rate swaps
Derivative [Line Items]
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income	0
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income		0
Product Revenues | Foreign exchange contracts
Derivative [Line Items]
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income	32
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income		212
Amount excluded from effectiveness testing recognized in earnings	78
Amount excluded from effectiveness testing recognized in earnings		0
Product Revenues | Cross currency interest rate swaps
Derivative [Line Items]
Amount excluded from effectiveness testing recognized in earnings	0
Amount excluded from effectiveness testing recognized in earnings		0
Cost of Goods, Total [Member] | Interest rate swaps
Derivative [Line Items]
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income		0
Cost of Goods, Total [Member] | Foreign exchange contracts
Derivative [Line Items]
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income		0
Amount excluded from effectiveness testing recognized in earnings		(19)
Cost of Goods, Total [Member] | Cross currency interest rate swaps
Derivative [Line Items]
Amount excluded from effectiveness testing recognized in earnings		0
Interest Expense | Interest rate swaps
Derivative [Line Items]
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income	301
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income		0
Interest Expense | Foreign exchange contracts
Derivative [Line Items]
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income	0
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income		0
Amount excluded from effectiveness testing recognized in earnings	0
Amount excluded from effectiveness testing recognized in earnings		0
Interest Expense | Cross currency interest rate swaps
Derivative [Line Items]
Amount excluded from effectiveness testing recognized in earnings	(314)
Amount excluded from effectiveness testing recognized in earnings		(271)
Product Revenues
Derivative [Line Items]
Product Revenues	217,768	163,829
Cost of services and products sold	$ 157,004	$ 119,678