Net Sales and Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Product Information [Line Items]
Net sales	$ 211,210	$ 212,055
North America [Member]
Product Information [Line Items]
Net sales	95,253	91,820
EMEA [Member]
Product Information [Line Items]
Net sales	56,288	62,055
Asia Pacific [Member]
Product Information [Line Items]
Net sales	50,527	48,777
South America [Member]
Product Information [Line Items]
Net sales	9,142	9,403
Transferred At Point In Time [Member]
Product Information [Line Items]
Net sales	206,432	207,152
Transferred At Point In Time [Member] | North America [Member]
Product Information [Line Items]
Net sales	92,483	88,986
Transferred At Point In Time [Member] | EMEA [Member]
Product Information [Line Items]
Net sales	56,234	61,999
Transferred At Point In Time [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net sales	48,651	46,848
Transferred At Point In Time [Member] | South America [Member]
Product Information [Line Items]
Net sales	9,064	9,319
Transferred Over Time [Member]
Product Information [Line Items]
Net sales	4,778	4,903
Transferred Over Time [Member] | North America [Member]
Product Information [Line Items]
Net sales	2,770	2,834
Transferred Over Time [Member] | EMEA [Member]
Product Information [Line Items]
Net sales	54	56
Transferred Over Time [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net sales	1,876	1,929
Transferred Over Time [Member] | South America [Member]
Product Information [Line Items]
Net sales	78	84
Primary Metals [Member]
Product Information [Line Items]
Net sales	101,950	101,078
Primary Metals [Member] | North America [Member]
Product Information [Line Items]
Net sales	39,685	37,558
Primary Metals [Member] | EMEA [Member]
Product Information [Line Items]
Net sales	24,883	27,314
Primary Metals [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net sales	32,092	30,907
Primary Metals [Member] | South America [Member]
Product Information [Line Items]
Net sales	5,290	5,299
Metalworking [Member]
Product Information [Line Items]
Net sales	88,913	93,068
Metalworking [Member] | North America [Member]
Product Information [Line Items]
Net sales	40,436	40,589
Metalworking [Member] | EMEA [Member]
Product Information [Line Items]
Net sales	28,248	31,170
Metalworking [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net sales	16,468	17,526
Metalworking [Member] | South America [Member]
Product Information [Line Items]
Net sales	3,761	3,783
Coatings And Other [Member]
Product Information [Line Items]
Net sales	20,347	17,909
Coatings And Other [Member] | North America [Member]
Product Information [Line Items]
Net sales	15,132	13,673
Coatings And Other [Member] | EMEA [Member]
Product Information [Line Items]
Net sales	3,157	3,571
Coatings And Other [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net sales	1,967	344
Coatings And Other [Member] | South America [Member]
Product Information [Line Items]
Net sales	$ 91	$ 321