GENERAL (Details) gal in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020 gal / d WaterSystem gal Facility Plan	Sep. 30, 2020 gal / d Subsidiary Squarefeet Facility
Business Operations [Abstract]
Number of wholly owned subsidiaries | Subsidiary		8
Number of subsidiaries not regulated | Subsidiary		3
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]
Business Operations [Abstract]
Number of wastewater treatment facilities owned and operated | Facility		4
Capacity of wastewater treatment facilities		500,000
Number of other's system efficiently and cost effectively manages wastewater transmission, treatment and disposal | WaterSystem	1
Disposal facility and spray irrigation to agricultural land | gal	90
Maximum supply amount of water per day	1,500,000
Artesian Utility [Member]
Business Operations [Abstract]
Capacity of wastewater treatment facilities		2,800,000
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 protection plans offered to customers | Plan	3