GOODWILL AND OTHER INTANGIBLE ASSETS - OTHER INTANGIBLE ASSETS (Details2) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	May 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Mar. 10, 2017	Dec. 31, 2016
Other intangible assets
Gross Value		$ 93,353		$ 93,353			$ 62,317
Accumulated Amortization		58,002		58,002			50,731
Net Value		35,351		35,351			11,586
Amortization expense		2,600	$ 2,100	$ 7,300	$ 6,700
GRR Acquisition | Weighted-average
Other intangible assets
Useful life of acquired intangible asset				12 years 6 months
Resource Water Acquisition | Weighted-average
Other intangible assets
Useful life of acquired intangible asset				8 years 7 months 6 days
Customer relationships
Other intangible assets
Gross Value		80,131		$ 80,131			56,826
Accumulated Amortization		54,987		54,987			48,236
Net Value		25,144		$ 25,144			8,590
Customer relationships | Minimum
Other intangible assets
Useful life of intangible asset				5 years
Customer relationships | Maximum
Other intangible assets
Useful life of intangible asset				7 years
Customer relationships | GRR Acquisition
Other intangible assets
Useful life of acquired intangible asset				13 years
Customer relationships | Resource Water Acquisition
Other intangible assets
Useful life of intangible asset				10 years
Noncompete agreements | Minimum
Other intangible assets
Useful life of intangible asset				3 years
Noncompete agreements | Maximum
Other intangible assets
Useful life of intangible asset				5 years
Noncompete agreements | GRR Acquisition
Other intangible assets
Useful life of acquired intangible asset				5 years
Noncompete agreements | Resource Water Acquisition
Other intangible assets
Useful life of intangible asset				3 years
Other
Other intangible assets
Gross Value		13,222		$ 13,222			5,491
Accumulated Amortization		3,015		3,015			2,495
Net Value		$ 10,207		$ 10,207			$ 2,996
Other | Minimum
Other intangible assets
Useful life of intangible asset				3 years
Other | Maximum
Other intangible assets
Useful life of intangible asset				8 years
Water rights | GRR Acquisition
Other intangible assets
Gross Value						$ 3,700
Patents
Other intangible assets
Gross Value	$ 1,900
Useful life of intangible asset	10 years