Other Items Impacting Comparability (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Items Impacting Comparability [Abstract]
Restructuring	$ (21,405)	$ (5,074)	$ (18,068)
Tax reform related bonus	(23,278)	0	0
Operating tax adjustment	(2,205)	0	0
Pension-related adjustments	(5,454)	(7,650)	509
Gain on sale of property (3)	24,122	0	0
Restructuring charges and fees, net and other items	$ (28,220)	$ (12,724)	$ (17,559)