Restructuring (Summary of Accrued Restructuring Costs) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Restructuring Reserve [Roll Forward]
Balance at December 31, 2018	$ 35,189
Charges	2,642	$ 0
Cash payments	(17,422)
Non-cash adjustments	(3,314)
Currency translation	81
Balance at March 31, 2019	17,176
Severance and employee-related costs
Restructuring Reserve [Roll Forward]
Balance at December 31, 2018	33,774
Charges	1,075
Cash payments	(17,089)
Non-cash adjustments	(737)
Currency translation	45
Balance at March 31, 2019	17,068
Other exit costs
Restructuring Reserve [Roll Forward]
Balance at December 31, 2018	1,415
Charges	1,567
Cash payments	(333)
Non-cash adjustments	(2,577)
Currency translation	36
Balance at March 31, 2019	$ 108