SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]
Sales	$ 348,504	$ 290,097
Operating income for reportable segments	37,099	35,349
Adjustment for [Abstract]
Amortization of intangibles	4,570	2,642
Corporate and other expense, net	10,368	10,003
Operating income	22,161	22,704
Interest expense, net	3,397	1,627
Other income, net	(150)	1
Income before income taxes	18,914	21,076
Service Centers [Member]
Segment Reporting Information [Line Items]
Sales	231,224	210,091
Operating income for reportable segments	24,425	25,047
IPS [Member]
Segment Reporting Information [Line Items]
Sales	79,881	41,523
Operating income for reportable segments	9,549	7,117
SCS [Member]
Segment Reporting Information [Line Items]
Sales	37,399	38,483
Operating income for reportable segments	$ 3,125	$ 3,185