SEGMENT AND GEOGRAPHIC REGION INFORMATION (Details 3) - 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
Sales to clients attributed to the geographic areas based on the origin of sale
Sales	$ 354,625	$ 327,737	$ 323,351	$ 296,559	$ 316,122	$ 291,256	$ 268,694	$ 256,820	$ 1,302,272	$ 1,132,892	$ 1,164,292
Property, plant, and equipment, net	214,953				200,630				214,953	200,630	197,084
United States
Sales to clients attributed to the geographic areas based on the origin of sale
Sales									1,066,810	977,669	1,031,920
Property, plant, and equipment, net	172,653				157,805				172,653	157,805	157,856
Canada
Sales to clients attributed to the geographic areas based on the origin of sale
Sales									37,299	52,894	36,813
Property, plant, and equipment, net	26,876				29,307				26,876	29,307	26,452
Europe
Sales to clients attributed to the geographic areas based on the origin of sale
Sales									197,401	100,233	93,420
Property, plant, and equipment, net	15,424				13,518				15,424	13,518	12,776
Mexico
Sales to clients attributed to the geographic areas based on the origin of sale
Sales									762	2,096	2,139
Property, plant, and equipment, net	$ 0				$ 0				$ 0	$ 0	$ 0