NON-UTILITY OPERATING REVENUE AND EXPENSES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Public Utility, Property, Plant and Equipment [Line Items]
Non-utility operating revenue	$ 4,686	$ 4,398	$ 4,150
Non-utility operating expenses	2,602	2,305	2,193
Artesian Utility [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Non-utility operating revenue	4,700	4,400	4,100
Non-utility operating expenses	$ 2,600	$ 2,300	$ 2,200