ACQUISITIONS AND DIVESTITURES (Narrative) (Details) $ in Thousands		3 Months Ended			6 Months Ended		12 Months Ended
		Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Jun. 30, 2020 USD ($) item	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Significant Acquisitions and Disposals [Line Items]
Cash consideration					$ 5,668	$ (1,122)
Number of facilities divested | item					2
Goodwill	[1]				$ 5,051
Gain on sale of property, plant & equipment and businesses		$ (258)	$ 3,451		741	10,748
Assets held for sale		$ 0	$ 0		0	$ 0	$ 0
Acquisitions 2020 [Member]
Significant Acquisitions and Disposals [Line Items]
Total consideration					35,862
Amortizable intangible assets recognized					$ 39,833
Estimated weighted-average amortization period of intangible assets					20 years
Goodwill					$ 5,051
Acquisitions 2019 [Member]
Significant Acquisitions and Disposals [Line Items]
Total consideration							45,273
Amortizable intangible assets recognized							$ 25,443
Estimated weighted-average amortization period of intangible assets					19 years 6 months
Intangible assets amortization period, tax purposes					15 years
New Mexico [Member]
Significant Acquisitions and Disposals [Line Items]
Supply agreement period		20 years
Georgia [Member]
Significant Acquisitions and Disposals [Line Items]
Gain on sale of property, plant & equipment and businesses				$ 4,064

[1] See Note 16 for summary of recent acquisitions.