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REVENUE (Details) - USD ($) $ in Thousands	3 Months Ended
REVENUE (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Deferred Revenue	$ 8,800		$ 11,800
Revenue from Contract with Customer, Excluding Assessed Tax	1,961,267	$ 1,993,915
Cost of goods sold	1,578,771	1,613,966
Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	736,906	758,976
Construction [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	633,288	637,800
Utility [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	308,269	315,546
Commercial, Institutional and Government [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	282,804	281,593
UNITED STATES
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,460,991	1,482,718
CANADA
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	384,596	398,738
Non-US [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	115,680	112,459
Shipping and Handling [Member]
Disaggregation of Revenue [Line Items]
Cost of goods sold	$ 17,000	$ 18,200