Exit Activity Costs and Asset Impairments (Narrative) (Details) $ in Thousands		12 Months Ended
	Apr. 15, 2016 USD ($)	Dec. 31, 2017 USD ($) facility	Dec. 31, 2016 USD ($) facility	Dec. 31, 2015 USD ($) facility
Restructuring and Related Activities [Abstract]
Exit activity charges		$ 5,495	$ 13,747	$ 3,123
Restructuring impairment charges		(1,630)	7,530	8,504
Exit activity costs		$ 7,125	$ 6,217	$ 1,418
Number of consolidated facilities to be closed | facility		3	7	4
Sale leaseback gain				$ 6,799
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 8,800
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Net of Tax	2,000
Net proceeds from sale of business	$ 8,300	$ 0	$ 8,250	$ 0