SEGMENT AND GEOGRAPHIC REGION INFORMATION (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Sales to clients attributed to the geographic areas based on the origin of sale
Sales to clients	$ 230,872	$ 216,898	$ 214,312	$ 200,586	$ 250,026	$ 219,794	$ 221,018	$ 196,662	$ 862,668	$ 887,499	$ 922,200
Property, plant, and equipment, net	137,893				124,838				137,893	124,838	121,792
United States
Sales to clients attributed to the geographic areas based on the origin of sale
Sales to clients									752,347	774,654	797,834
Property, plant, and equipment, net	94,896				80,953				94,896	80,953	77,230
Canada
Sales to clients attributed to the geographic areas based on the origin of sale
Sales to clients									36,240	40,669	44,225
Property, plant, and equipment, net	27,938				29,064				27,938	29,064	29,110
Europe
Sales to clients attributed to the geographic areas based on the origin of sale
Sales to clients									74,081	72,176	80,141
Property, plant, and equipment, net	$ 15,059				$ 14,821				$ 15,059	$ 14,821	$ 15,452