SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Utility Subsidiary Accounting [Abstract]
Number of wholly owned subsidiaries	5
Utility Plant [Abstract]
Deferred credits and other liabilities	$ 60,990	$ 57,235
Capitalized rate of AFUDC (in hundredths)	8.20%	8.20%	7.90%
Summary of utility plant comprises [Abstract]
Utility plant, gross	450,037	430,407
Less - accumulated depreciation	83,474	77,010
Utility plant, net	366,563	353,397
Depreciation and Amortization [Abstract]
Depreciation rates of water utility plant (in hundredths)	2.29%	2.22%	2.18%
Minimum [Member]
Depreciation and Amortization [Abstract]
Amortization period of other deferred assets	2 years
Maximum [Member]
Depreciation and Amortization [Abstract]
Amortization period of other deferred assets	40 years
Property Held for Future Use [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	0 years
Utility plant, gross	14,525	13,157
Construction in Progress [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	0 years
Utility plant, gross	6,198	4,894
Utility Plant [Member]
Utility Plant [Abstract]
Deferred credits and other liabilities	1,200
Utility plant in service-Water [Member] \| Mains [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	81 years
Utility plant in service-Water [Member] \| Services [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	39 years
Utility plant in service-Water [Member] \| Storage Tanks [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	76 years
Utility plant in service-Water [Member] \| Meters [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	26 years
Utility plant in service-Water [Member] \| Hydrants [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	60 years
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	17,663	17,247
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	64,200	59,302
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] \| Transmission and Distribution Plant [Member] \| Mains [Member]
Summary of utility plant comprises [Abstract]
Utility plant, gross	195,671	187,993
Utility plant in service-Water [Member] \| Transmission and Distribution Plant [Member] \| Services [Member]
Summary of utility plant comprises [Abstract]
Utility plant, gross	31,627	30,918
Utility plant in service-Water [Member] \| Transmission and Distribution Plant [Member] \| Storage Tanks [Member]
Summary of utility plant comprises [Abstract]
Utility plant, gross	23,814	23,122
Utility plant in service-Water [Member] \| Transmission and Distribution Plant [Member] \| Meters [Member]
Summary of utility plant comprises [Abstract]
Utility plant, gross	20,652	19,915
Utility plant in service-Water [Member] \| Transmission and Distribution Plant [Member] \| Hydrants [Member]
Summary of utility plant comprises [Abstract]
Utility plant, gross	10,505	10,241
Utility plant in service-Water [Member] \| General plant [Member]
Summary of utility plant comprises [Abstract]
Utility plant, gross	46,520	44,857
Utility plant in service-Water [Member] \| General plant [Member] \| Minimum [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	3 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] \| General plant [Member]
Summary of utility plant comprises [Abstract]
Utility plant, gross	783	1,107
Utility plant in service-Wastewater [Member] \| General plant [Member] \| Minimum [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	3 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	11,708	11,248
Utility plant in service-Wastewater [Member] \| Treatment and Disposal Plant [Member] \| Minimum [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	35 years
Utility plant in service-Wastewater [Member] \| Treatment and Disposal Plant [Member] \| Maximum [Member]
Summary of utility plant comprises [Abstract]
Estimated useful life	62 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	$ 6,031	$ 6,266