Net Sales and Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax	$ 211,481	$ 222,022	$ 221,962	$ 212,055	$ 211,072	$ 212,918	$ 201,183	$ 194,909	$ 867,520	$ 820,082	$ 746,665
North America [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									383,471	356,598	336,174
EMEA [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									233,597	226,243	200,917
Asia Pacific [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									214,157	201,008	179,131
South America [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									36,295	$ 36,233	$ 30,443
Transferred At Point In Time [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									847,886
Transferred At Point In Time [Member] | North America [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									372,392
Transferred At Point In Time [Member] | EMEA [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									233,372
Transferred At Point In Time [Member] | Asia Pacific [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									206,112
Transferred At Point In Time [Member] | South America [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									36,010
Transferred Over Time [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									19,634
Transferred Over Time [Member] | North America [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									11,079
Transferred Over Time [Member] | EMEA [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									225
Transferred Over Time [Member] | Asia Pacific [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									8,045
Transferred Over Time [Member] | South America [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									285
Primary Metals [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									413,536
Primary Metals [Member] | North America [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									156,906
Primary Metals [Member] | EMEA [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									102,417
Primary Metals [Member] | Asia Pacific [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									134,395
Primary Metals [Member] | South America [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									19,818
Metalworking [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									373,599
Metalworking [Member] | North America [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									167,829
Metalworking [Member] | EMEA [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									116,076
Metalworking [Member] | Asia Pacific [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									74,867
Metalworking [Member] | South America [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									14,827
Coatings and Other [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									80,385
Coatings and Other [Member] | North America [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									58,736
Coatings and Other [Member] | EMEA [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									15,104
Coatings and Other [Member] | Asia Pacific [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									4,895
Coatings and Other [Member] | South America [Member]
Product Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									$ 1,650