Rationalization Charges Details (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Restructuring Cost and Reserve [Line Items]
Rationalization charges	$ 492	$ 3,038	$ 1,195	$ 3,923
Cash Payments for Restructuring			1,300	$ 2,100
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	1,400		1,400
Remaining cash expenditures for our rationalization plans expected through 2023			3,300
Accrued Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Balance at June 30, 2018	800		800
Other Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Balance at June 30, 2018	$ 1,100		$ 1,100