Product Warranty (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Activity for accrued warranty expense
Balance at beginning of period	$ 3,779	$ 3,784	$ 3,526	$ 3,345
Provision	1,525	1,493	3,845	4,291
Claims paid/costs incurred	(1,499)	(1,542)	(3,626)	(3,916)
Foreign currency translation	73	(9)	133	6
Balance at end of period	$ 3,878	$ 3,726	$ 3,878	$ 3,726
Maximum
Product Warranty Liability [Line Items]
Product Warranty			2 years
Minimum
Product Warranty Liability [Line Items]
Product Warranty			1 year