CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Statement of Financial Position [Abstract]
UTILITY PLANT: Water Production	$ 323,691	$ 314,924
Transmission and Distribution	890,445	855,497
General	106,949	105,167
Construction Work in Progress	43,615	34,209
TOTAL	1,364,700	1,309,797
Less Accumulated Depreciation	264,521	254,425
UTILITY PLANT - NET	1,100,179	1,055,372
CURRENT ASSETS: Cash and Cash Equivalents	2,560	4,226
Accounts Receivable, net of allowance for credit losses of $2,101 and $2,695 in 2025 and 2024, respectively	20,888	18,842
Unbilled Revenues	13,101	10,764
Materials and Supplies (at average cost)	6,923	6,719
Prepayments	6,038	2,422
TOTAL CURRENT ASSETS	49,510	42,973
OTHER ASSETS: Operating Lease Right of Use Asset	2,268	2,567
Restricted Cash	1,675
Regulatory Assets	105,448	101,783
Non-utility Assets - Net	12,061	11,760
Employee Benefit Plans	39,274	36,856
Other	5,475	3,863
TOTAL OTHER ASSETS	166,201	156,829
TOTAL ASSETS	1,315,890	1,255,174
CAPITALIZATION AND LIABILITIES
CAPITALIZATION: Common Stock, No Par Value, authorized 40,000, issued 18,016 and 17,887 in 2025 and 2024, respectively	252,688	248,202
Retained Earnings	205,095	197,061
TOTAL COMMON EQUITY	457,783	445,263
Preferred Stock, No Par Value; authorized 120; issued 13	1,352	1,635
Long-term Debt	351,084	352,822
TOTAL CAPITALIZATION	810,219	799,720
CURRENT Current Portion of Long-term Debt	7,633	7,711
LIABILITIES: Notes Payable	55,200	23,000
Accounts Payable	30,779	28,050
Accrued Taxes	15,371	11,976
Accrued Interest	3,070	2,916
Unearned Revenues and Advanced Service Fees	1,841	1,476
Other	7,588	7,759
TOTAL CURRENT LIABILITIES	121,482	82,888
COMMITMENTS AND CONTINGENT LIABILITIES (Note 7)
OTHER LIABILITIES: Advances for Construction	23,447	22,629
Lease Obligations	2,116	2,432
Accumulated Deferred Income Taxes	107,321	101,235
Regulatory Liabilities	63,836	64,557
Other	286	344
TOTAL OTHER LIABILITIES	197,006	191,197
CONTRIBUTIONS IN AID OF CONSTRUCTION	187,183	181,369
TOTAL CAPITALIZATION AND LIABILITIES	$ 1,315,890	$ 1,255,174