ACQUISITIONS (Purchase Price Allocation) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2017	Jun. 30, 2018	Dec. 31, 2017
Business Acquisition
Goodwill		$ 235,408	$ 236,810
Headwater Companies
Business Acquisition
Cash	$ 2,700
Receivables	29,900
Inventory	56,000
Other current assets	5,100
Total current assets	93,700
Property, plant, and equipment	9,800
Intangible assets	5,700
Goodwill	33,900
Other assets	200
Total assets	143,300
Accounts payable	(19,600)
Accrued liabilities and other current liabilities	(11,400)
Current maturities of long-term debt	(31,600)
Total current liabilities	(62,600)
Long-term debt	(2,000)
Other long-term liabilities	(700)
Total liabilities	(65,300)
Total	78,000
Less: Fair value of original equity interest	(20,600)
Total purchase price	$ 57,400