Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities:
Net income (loss)	$ 95,263	$ 100,979	$ 96,831
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	117,364	111,581	100,935
Amortization of debt premium and expenses	369	366	412
Changes in normalized deferred income taxes	26,880	25,200	34,440
Change in value of life insurance contracts	7,161	(3,800)	(4,293)
Allowance for equity funds used during construction	(4,127)	(3,186)	(4,976)
Stock-based compensation	5,161	6,805	4,590
Gain on sale of non-utility properties	0	(94)	0
Write-off of capital costs	702	524	0
Changes in operating assets and liabilities:
Receivables	(40,687)	(12,833)	(18,343)
Water Arrearages Payment Program cash received	20,836	0	0
Water Arrearages Payment Program cash returned	(3,609)	0	0
Unbilled revenue	(381)	1,309	1,148
Taxes, prepaid expenses, and other assets	(5,104)	(2,745)	(3,647)
Accounts payable	(7,626)	(2,938)	373
Other current liabilities	7,941	1,141	(6,097)
Other changes in noncurrent assets and liabilities	23,629	9,409	(83,449)
Net cash provided by operating activities	243,772	231,718	117,924
Investing activities:
Utility plant expenditures	(327,757)	(293,194)	(298,651)
Proceeds from sale of non-utility properties	0	108	0
Business Acquisition, net of cash acquired	0	(6,451)	(40,483)
Asset acquisition	(7,766)	0	0
Payment for investments	0	0	(4,600)
Return of investment	0	1,000	0
Purchase of life insurance	(6,688)	(2,335)	(2,335)
Life insurance proceeds	6,688	0	0
Net cash used in investing activities	(335,523)	(300,872)	(346,069)
Financing activities:
Short-term borrowings	150,000	200,000	335,000
Repayment of short-term borrowings	(115,000)	(535,000)	(140,100)
Issuance of long-term debt, net of debt issuance costs of $0 for 2022, $1,064 for 2021, and $0 for 2020.	0	278,936	0
Advances and contributions in aid of construction	25,822	28,171	27,292
Refunds of advances for construction	(9,468)	(10,634)	(10,203)
Retirement of long-term debt	(5,423)	(5,353)	(22,141)
Repurchase of common stock	(2,013)	(1,767)	(1,679)
Issuance of common stock	106,739	197,723	83,575
Dividends paid	(54,186)	(47,398)	(41,768)
Distribution to noncontrolling interest	(348)	0	0
Net cash provided by financing activities	96,123	104,678	229,976
Change in cash, cash equivalents, and restricted cash	4,372	35,524	1,831
Cash, cash equivalents, and restricted cash at beginning of year	80,653	45,129	43,298
Cash, cash equivalents, and restricted cash at end of year	85,025	80,653	45,129
Cash paid during the year for:
Interest (net of amounts capitalized)	43,768	41,621	40,792
Income taxes	0	3,661	4,700
Supplemental disclosure of investing and financing non-cash activities:
Accrued payables for investments in utility plant	51,511	57,768	54,987
Utility plant contributed by developers	20,379	19,531	28,672
Litigation proceeds for TCP contamination reclassified from liability to depreciable plant and equipment	$ 0	$ 9,302	$ 445