Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 9,303	$ 9,084	$ 8,929
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	5,170	4,905	4,592
Increase in deferred income taxes	2,311	3,189	2,591
Other	208	378	99
Changes in assets and liabilities:
Increase in accounts receivable and unbilled revenues	(699)	(172)	(1,106)
(Increase) decrease in recoverable income taxes	197	(176)	(21)
Increase in materials and supplies, prepaid expenses, regulatory and other assets	(650)	(1,300)	(614)
Increase in accounts payable, accrued compensation and benefits, accrued expenses, deferred employee benefits, and other deferred credits	486	1,569	701
Increase (decrease) in accrued interest and taxes	96	(3)	(416)
Net cash provided by operating activities	16,422	17,474	14,755
CASH FLOWS FROM INVESTING ACTIVITIES:
Utility plant additions, including debt portion of allowance for funds used during construction of $59 in 2012, $55 in 2011 and $62 in 2010	(11,543)	(9,472)	(10,541)
Acquisitions of water and wastewater systems	(661)	0	0
Decrease in notes receivable	30	39	69
Net cash used in investing activities	(12,174)	(9,433)	(10,472)
CASH FLOWS FROM FINANCING ACTIVITIES:
Customers' advances for construction and contributions in aid of construction	780	124	428
Repayments of customer advances	(304)	(295)	(544)
Proceeds of long-term debt issues	0	0	39,491
Debt issuance costs	0	0	(703)
Repayments of long-term debt	(42)	(156)	(34,886)
Borrowings under short-term line of credit agreements	0	0	(2,000)
Changes in cash overdraft position	0	0	(195)
Issuance of common stock	2,186	1,632	1,912
Dividends paid	(6,862)	(6,667)	(6,459)
Net cash used in financing activities	(4,242)	(5,362)	(2,956)
Net change in cash and cash equivalents	6	2,679	1,327
Cash and cash equivalents at beginning of period	4,006	1,327	0
Cash and cash equivalents at end of period	4,012	4,006	1,327
Cash paid during the period for:
Interest, net of amounts capitalized	5,192	5,202	4,797
Income taxes	$ 2,703	$ 1,625	$ 3,513