Consolidated Statements Of Cash Flow - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net income	$ 281,667	$ 264,603
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	157,522	147,116
Deferred income taxes	(13,810)	19,594
Provision for doubtful accounts	12,793	16,511
Stock-based compensation	5,471	5,053
Gain on sale of other assets	(478)	(808)
Net change in receivables, inventory and prepayments	6,742	55,561
Net change in payables, accrued interest, accrued taxes and other accrued liabilities	(4,222)	(78,587)
Pension and other postretirement benefits contributions	(14,564)	(12,971)
Other	(14,819)	(3,204)
Net cash flows from operating activities	416,302	412,868
Cash flows from investing activities:
Property, plant and equipment additions, including the debt component of allowance for funds used during construction of $3,013 and $1,393	(424,645)	(404,557)
Acquisitions of utility systems, net	(50,010)
Net proceeds from the sale of other assets	485	960
Other	157	(184)
Net cash flows used in investing activities	(474,013)	(403,781)
Cash flows from financing activities:
Customers' advances and contributions in aid of construction	5,796	8,988
Repayments of customers' advances	(901)	(1,961)
Net repayments of short-term debt	(60,297)	(6,349)
Proceeds from long-term debt	770,376	760,176
Repayments of long-term debt	(464,585)	(619,477)
Change in cash overdraft position	(61,061)	(30,595)
Proceeds from issuance of common stock under dividend reinvestment plan	8,171	8,256
Proceeds from exercised stock options	1,239	1,506
Repurchase of common stock	(1,027)	(3,279)
Dividends paid on common stock	(138,108)	(123,104)
Other	517	329
Net cash flows from (used in) financing activities	60,120	(5,510)
Net change in cash and cash equivalents	2,409	3,577
Cash and cash equivalents at beginning of period	10,567	4,827
Cash and cash equivalents at end of period	12,976	8,404
Non-cash investing activities:
Property, plant and equipment additions purchased at the period end, but not yet paid for	94,473	74,752
Non-cash customer advances and contributions in aid of construction	$ 8,789	$ 17,651