Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net income	$ 100,979	$ 96,831	$ 63,116
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	111,581	100,935	91,288
Amortization of debt premium and expenses	366	412	744
Changes in normalized deferred income taxes	25,200	34,440	15,346
Change in value of life insurance contracts	(3,800)	(4,293)	(5,104)
Allowance for equity funds used during construction	(3,186)	(4,976)	(6,685)
Stock-based compensation	6,805	4,590	6,731
Gain on sale of non-utility properties	(94)	0	(28)
Write-off of capital costs	524	0	698
Changes in operating assets and liabilities:
Receivables	(12,833)	(18,343)	(4,580)
Unbilled revenue	1,309	1,148	(1,452)
Taxes, prepaid expenses, and other assets	(2,745)	(3,647)	(3,545)
Accounts payable	(2,938)	373	10,719
Other current liabilities	1,141	(6,097)	1,282
Other changes in noncurrent assets and liabilities	9,409	(83,449)	264
Net cash provided by operating activities	231,718	117,924	168,794
Investing activities:
Utility plant expenditures	(293,194)	(298,651)	(273,770)
Proceeds from sale of non-utility properties	108	0	28
Business Acquisition, net of cash acquired	(6,451)	(40,483)	0
Payment for investments	0	(4,600)	0
Return of investment	1,000	0	0
Purchase of life insurance	(2,335)	(2,335)	(2,216)
Net cash used in investing activities	(300,872)	(346,069)	(275,958)
Financing activities:
Short-term borrowings	200,000	335,000	260,000
Repayment of short-term borrowings	(535,000)	(140,100)	(150,000)
Issuance of long-term debt, net of debt issuance costs of $1,064 for 2021, $0 for 2020, and $1,796 for 2019.	278,936	0	398,204
Advances and contributions in aid of construction	28,171	27,292	27,774
Refunds of advances for construction	(10,634)	(10,203)	(7,566)
Retirement of long-term debt	(5,353)	(22,141)	(405,568)
Repurchase of common stock	(1,767)	(1,679)	(2,497)
Issuance of common stock	197,723	83,575	20,423
Dividends paid	(47,398)	(41,768)	(38,023)
Net cash provided by financing activities	104,678	229,976	102,747
Change in cash, cash equivalents, and restricted cash	35,524	1,831	(4,417)
Cash, cash equivalents, and restricted cash at beginning of year	45,129	43,298	47,715
Cash, cash equivalents, and restricted cash at end of year	80,653	45,129	43,298
Cash paid during the year for:
Interest (net of amounts capitalized)	41,621	40,792	40,980
Income taxes	3,661	4,700	0
Supplemental disclosure of investing and financing non-cash activities:
Accrued payables for investments in utility plant	57,768	54,987	40,794
Utility plant contributed by developers	19,531	28,672	16,288
Litigation proceeds for TCP contamination reclassified from liability to depreciable plant and equipment	$ 9,302	$ 445	$ 13,968