Restructuring Charges (Restructuring Charges) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Restructuring Costs
Balance Beginning	$ 15,449	$ 43,720
Expenses, net	3,598	904
Cash payments	(8,144)	(15,585)
Balance Ending	$ 10,903	29,039
Minimum
Restructuring Costs
Restructuring reserve, expected payment period	12 months
Maximum
Restructuring Costs
Restructuring reserve, expected payment period	24 months
Severance and benefits costs
Restructuring Costs
Balance Beginning	$ 13,641	42,151
Expenses, net	3,330	835
Cash payments	(7,191)	(15,008)
Balance Ending	9,780	27,978
Other exit costs
Restructuring Costs
Balance Beginning	1,808	1,569
Expenses, net	268	69
Cash payments	(953)	(577)
Balance Ending	$ 1,123	$ 1,061