Net Sales and Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Product Information [Line Items]
Net Sales	$ 222,022	$ 212,918	$ 656,039	$ 609,010
North America [Member]
Product Information [Line Items]
Net Sales	101,706	90,450	290,918	268,122
EMEA [Member]
Product Information [Line Items]
Net Sales	55,498	58,775	177,719	167,209
Asia Pacific [Member]
Product Information [Line Items]
Net Sales	55,757	54,200	159,882	147,074
South America [Member]
Product Information [Line Items]
Net Sales	9,061	$ 9,493	27,520	$ 26,605
Transferred At Point In Time [Member]
Product Information [Line Items]
Net Sales	217,392		641,220
Transferred At Point In Time [Member] | North America [Member]
Product Information [Line Items]
Net Sales	98,965		282,513
Transferred At Point In Time [Member] | EMEA [Member]
Product Information [Line Items]
Net Sales	55,437		177,546
Transferred At Point In Time [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net Sales	53,998		153,863
Transferred At Point In Time [Member] | South America [Member]
Product Information [Line Items]
Net Sales	8,992		27,298
Transferred Over Time [Member]
Product Information [Line Items]
Net Sales	4,630		14,819
Transferred Over Time [Member] | North America [Member]
Product Information [Line Items]
Net Sales	2,741		8,405
Transferred Over Time [Member] | EMEA [Member]
Product Information [Line Items]
Net Sales	61		173
Transferred Over Time [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net Sales	1,759		6,019
Transferred Over Time [Member] | South America [Member]
Product Information [Line Items]
Net Sales	69		222
Primary Metals [Member]
Product Information [Line Items]
Net Sales	104,525		311,007
Primary Metals [Member] | North America [Member]
Product Information [Line Items]
Net Sales	40,448		117,174
Primary Metals [Member] | EMEA [Member]
Product Information [Line Items]
Net Sales	24,188		77,692
Primary Metals [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net Sales	35,108		101,026
Primary Metals [Member] | South America [Member]
Product Information [Line Items]
Net Sales	4,781		15,115
Metalworking [Member]
Product Information [Line Items]
Net Sales	96,528		285,520
Metalworking [Member] | North America [Member]
Product Information [Line Items]
Net Sales	45,189		128,709
Metalworking [Member] | EMEA [Member]
Product Information [Line Items]
Net Sales	27,986		88,909
Metalworking [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net Sales	19,585		56,486
Metalworking [Member] | South America [Member]
Product Information [Line Items]
Net Sales	3,768		11,416
Coatings and Other [Member]
Product Information [Line Items]
Net Sales	20,969		59,512
Coatings and Other [Member] | North America [Member]
Product Information [Line Items]
Net Sales	16,069		45,035
Coatings and Other [Member] | EMEA [Member]
Product Information [Line Items]
Net Sales	3,324		11,118
Coatings and Other [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net Sales	1,064		2,370
Coatings and Other [Member] | South America [Member]
Product Information [Line Items]
Net Sales	$ 512		$ 989