Rationalization Charges Details (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Restructuring Cost and Reserve [Line Items]
Rationalization charges	$ 288	$ 561	$ 1,483	$ 4,485
Cash payments for restructuring			1,800	$ 2,800
Other Restructuring [Member] | Rationalization Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expenses for our rationalization plans expected primarily within the next twelve months	1,100		1,100
Remaining cash expenditures for our rationalization plans expected through 2023			2,800
Accrued Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Rationalization reserves	700		700
Other Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Rationalization reserves	$ 1,000		$ 1,000