GENERAL (Details) gal in Millions		3 Months Ended
	Jan. 27, 2017 gal / d mi gal	Mar. 31, 2018 gal / d Subsidiary Facility WaterSystem Squarefeet Customer
Number of wholly owned subsidiaries | Subsidiary		9
Number of subsidiaries not regulated | Subsidiary		4
Artesian Development purchased area of office space (in square feet) | Squarefeet		10,000
Artesian Development purchased area of warehouse space (in square feet) | Squarefeet		10,000
Artesian Wastewater [Member]
Number of wastewater treatment facilities owned and operated | Facility		4
Capacity of wastewater treatment facilities		500,000
Allen Harim Foods, LLC [Member]
Capacity of wastewater treatment facilities	1,500,000
Approximate pipeline mileage | mi	8
Volume of storage lagoon | gal	90
Artesian Water Maryland [Member]
Number of public water systems owned and operated | WaterSystem		8
Maximum supply amount of water per day		1,000,000
Artesian Utility [Member]
Initial contract period of operating wastewater treatment facilities in Middletown		20 years
Number of wastewater treatment station facility operations in Middletown | Facility		2
Number of wastewater treatment facilities in Middletown providing reclaimed wastewater | Facility		1
Number of water service line protection plan customers | Customer		19,500
Number of sewer service line protection plan customers | Customer		15,400
Percentage of water service line protection plan customers signed up		24.50%
Percentage of sewer service protection plan customers signed up		19.40%
Percentage of internal service protection plan eligible customers signed up		6.10%
Number of internal service line protection plan customers | Customer		4,900
Number of non customers signed up with plan | Customer		1,600
Artesian Utility [Member] | Wastewater treatment facility first of two [Member] | Maximum [Member]
Capacity of wastewater treatment facilities		2,500,000
Artesian Utility [Member] | Wastewater treatment facility second of two [Member] | Maximum [Member]
Capacity of wastewater treatment facilities		250,000