BUSINESS SEGMENT INFORMATION (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2024 USD ($) Subsidiary Segment	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
BUSINESS SEGMENT INFORMATION [Abstract]
Number of reportable segments | Segment		1
Number of regulated utility subsidiaries | Subsidiary		5
Segment Reporting, Revenue [Abstract]
Revenues		$ 107,952	$ 98,861	$ 98,897
Segment Reporting, Operating Income [Abstract]
Depreciation and amortization		13,629	13,335	12,620
Income taxes		7,315	6,348	5,878
Property and other taxes		6,318	6,099	5,871
Operating Income		26,151	22,446	23,906
Segment Reporting, Assets [Abstract]
Assets		798,623	766,832
Intersegment Eliminations [Member]
Segment Reporting, Revenue [Abstract]
Revenues		(272)	(244)	(169)
Regulated Utility [Member] | Operating Segments [Member]
Segment Reporting, Revenue [Abstract]
Revenues		101,210	92,228	89,818
Segment Reporting, Operating Income [Abstract]
Payroll and benefits expense	[1],[2]	25,975	25,031	24,018
Supply and delivery	[2],[3]	14,704	12,595	11,936
Administrative	[2],[4]	9,389	8,823	7,987
Depreciation and amortization	[2]	13,578	13,281	12,563
Income taxes	[2]	6,552	5,216	5,091
Property and other taxes	[2]	6,255	6,036	5,812
Operating Income	[2]	24,757	21,246	22,411
Segment Reporting, Assets [Abstract]
Assets		793,118	760,339
Other Operating Segment [Member] | Operating Segments [Member]
Segment Reporting, Revenue [Abstract]
Revenues	[5]	7,014	6,877	9,248
Segment Reporting, Operating Income [Abstract]
Operating Income	[5]	1,394	1,200	1,495
Segment Reporting, Assets [Abstract]
Assets		5,505	6,493
Reportable Segment, Aggregation before Other Operating Segment [Member] | Operating Segments [Member]
Segment Reporting, Revenue [Abstract]
Revenues		101,210	92,228	89,818
Segment Reporting, Operating Income [Abstract]
Operating Income	[2]	24,757	21,246	$ 22,411
Segment Reporting, Assets [Abstract]
Assets		$ 793,118	$ 760,339

[1] Payroll and benefits:

[2] – The significant expense categories and amounts align with the segment-level information that is regularly provided to the CODM– Inter-segment expenses related to leased space provided by one non-utility business, calculated on the lower of cost or market method, are included in the amounts shown

[3] Supply and Delivery: – This category includes purchased power, purchased water, chemicals, infrastructure maintenance and repair costs, and wastewater disposal fees

[4] Administration expense:– This category includes computer systems maintenance and subscription fees, audit and legal fees, insurance, customer billing, and other general and administrative expenses

[5] – Revenue and profit from segments below the quantitative thresholds are attributable to four non-utility businesses of the Company– These businesses are primarily comprised of: Service Line Protection Plan services for water, sewer and internal plumbing; design, construction and engineering services; contract services for the operation and maintenance of water and wastewater systems in Delaware and Maryland; and leased space to the Regulated Utility Segment– These non-utility businesses do not individually or in the aggregate meet the quantitative thresholds for determining reportable segments– Certain corporate costs have been allocated from the regulated utility segment to the non-utility businesses and are included in the other profit amounts shown