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Cost incurred during the reporting period in transporting goods and services to customers. Includes freight-out costs.

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REVENUE (Details) - USD ($) $ in Thousands	3 Months Ended
REVENUE (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Deferred Revenue	$ 11,200		$ 15,500
Revenue from Contract with Customer, Excluding Assessed Tax	1,993,915	$ 1,772,591
Shipping, Handling and Transportation Costs	18,200	13,300
Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	758,976	678,292
Construction [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	637,800	571,636
Utility [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	315,546	266,259
Commercial, Institutional and Government [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	281,593	256,404
UNITED STATES
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,482,718	1,343,217
Non-US [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 511,197	$ 429,374