SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Part 1 (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) Subsidiary	Dec. 31, 2019 USD ($)	Dec. 31, 2018	Aug. 03, 2020 USD ($)
Utility Subsidiary Accounting [Abstract]
Number of wholly owned subsidiaries | Subsidiary	5
Summary of utility plant comprises [Abstract]
Utility plant, gross	$ 707,030	$ 667,309
Less - accumulated depreciation	147,469	136,588
Utility plant, net	$ 559,561	$ 530,721
Depreciation and Amortization [Abstract]
Depreciation rates of water utility plant	2.23%	2.27%	2.28%
Minimum [Member]
Depreciation and Amortization [Abstract]
Amortization period of other deferred assets	20 years
Maximum [Member]
Depreciation and Amortization [Abstract]
Amortization period of other deferred assets	24 years
Property Held for Future Use [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	0 years
Utility plant, gross	$ 5,711	$ 24,632
Construction in Progress [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	0 years
Utility plant, gross	$ 21,474	31,881
Source of supply plant [Member]
Summary of utility plant comprises [Abstract]
Utility plant, net				$ 201
Pumping and water treatment plant [Member]
Summary of utility plant comprises [Abstract]
Utility plant, net				$ 1,455
Utility plant in service-Water [Member] | Mains [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	81 years
Utility plant, gross	$ 293,643	277,125
Utility plant in service-Water [Member] | Services [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	39 years
Utility plant, gross	$ 49,937	48,190
Utility plant in service-Water [Member] | Storage Tanks [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	76 years
Utility plant, gross	$ 29,946	27,968
Utility plant in service-Water [Member] | Meters [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	26 years
Utility plant, gross	$ 27,994	27,498
Utility plant in service-Water [Member] | Hydrants [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	60 years
Utility plant, gross	$ 15,895	15,071
Utility plant in service-Water [Member] | Intangible plant [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	0 years
Utility plant, gross	$ 140	140
Utility plant in service-Water [Member] | Source of supply plant [Member]
Summary of utility plant comprises [Abstract]
Utility plant, gross	$ 23,940	22,611
Utility plant in service-Water [Member] | Source of supply plant [Member] | Minimum [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	45 years
Utility plant in service-Water [Member] | Source of supply plant [Member] | Maximum [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	85 years
Utility plant in service-Water [Member] | Pumping and water treatment plant [Member]
Summary of utility plant comprises [Abstract]
Utility plant, gross	$ 100,317	90,795
Utility plant in service-Water [Member] | Pumping and water treatment plant [Member] | Minimum [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	8 years
Utility plant in service-Water [Member] | Pumping and water treatment plant [Member] | Maximum [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	62 years
Utility plant in service-Water [Member] | General plant [Member]
Summary of utility plant comprises [Abstract]
Utility plant, gross	$ 62,379	61,512
Utility plant in service-Water [Member] | General plant [Member] | Minimum [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	5 years
Utility plant in service-Water [Member] | General plant [Member] | Maximum [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	31 years
Utility plant in service-Wastewater [Member] | Intangible plant [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	0 years
Utility plant, gross	$ 116	0
Utility plant in service-Wastewater [Member] | General plant [Member]
Summary of utility plant comprises [Abstract]
Utility plant, gross	$ 1,545	1,223
Utility plant in service-Wastewater [Member] | General plant [Member] | Minimum [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	5 years
Utility plant in service-Wastewater [Member] | General plant [Member] | Maximum [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	31 years
Utility plant in service-Wastewater [Member] | Treatment and Disposal Plant [Member]
Summary of utility plant comprises [Abstract]
Utility plant, gross	$ 41,860	19,315
Utility plant in service-Wastewater [Member] | Treatment and Disposal Plant [Member] | Minimum [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	21 years
Utility plant in service-Wastewater [Member] | Treatment and Disposal Plant [Member] | Maximum [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	81 years
Utility plant in service-Wastewater [Member] | Collection Mains & Lift Stations [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	81 years
Utility plant, gross	$ 32,133	$ 19,348
Artesian Water [Member]
Utility Plant [Abstract]
Capitalized rate of AFUDC	7.00%	7.10%	7.40%
Artesian Wastewater [Member]
Utility Plant [Abstract]
Capitalized rate of AFUDC	6.30%	7.10%	5.90%