Segment Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) segment	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	3
Segment Information
Net sales	$ 244,779	$ 219,867
Income (Loss) from Operations	32,796	22,630
Total Assets	1,040,342	1,018,200	$ 1,037,523
Cash and cash equivalent	137,413	167,059	168,514	$ 226,537
Intersegment elimination
Segment Information
Net sales	7,501	5,946
Administrative and all other
Segment Information
Income (Loss) from Operations	(1,676)	(2,107)
Total Assets	(183,527)	(72,766)	(150,970)
Cash and cash equivalent	53,400	92,100	80,200
North America
Segment Information
Net sales	206,212	183,772
Income (Loss) from Operations	35,968	26,767
Total Assets	982,149	877,408	953,033
North America | Intersegment elimination
Segment Information
Net sales	628	850
Europe
Segment Information
Net sales	36,293	34,381
Income (Loss) from Operations	(1,647)	(1,835)
Total Assets	213,259	187,614	208,640
Europe | Intersegment elimination
Segment Information
Net sales	349	147
Asia/Pacific
Segment Information
Net sales	2,274	1,714
Income (Loss) from Operations	151	(195)
Total Assets	28,461	25,944	$ 26,820
Asia/Pacific | Intersegment elimination
Segment Information
Net sales	$ 6,524	$ 4,949