Acquisition, Restructuring and Other Expense (Restructuring Accrual) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restructuring accrual
Restructuring accrual, beginning balance	$ 7,175	$ 8,254	$ 3,128
Expenses incurred	9,939	21,671	21,512
Payments made	(14,471)	(22,750)	(16,386)
Restructuring accrual, ending balance	$ 2,643	$ 7,175	$ 8,254