Consolidated Statements Of Cash Flow - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net income	$ 362,778	$ 350,305
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	255,490	240,252
Deferred income taxes	(40,541)	(12,794)
Provision for doubtful accounts	17,021	18,519
Stock-based compensation	8,929	8,164
Gain on sale of utility systems and other assets	(184)	(777)
Net change in receivables, deferred purchased gas costs, inventory and prepayments	265,922	(116,804)
Net change in payables, accrued interest, accrued taxes and other accrued liabilities	(5,266)	65,845
Pension and other postretirement benefits contributions	(20,343)	(20,390)
Other	(39,237)	(13,161)
Net cash flows from operating activities	804,569	519,159
Cash flows from investing activities:
Property, plant and equipment additions, including the debt component of allowance for funds used during construction of $4,502 and $4,527	(874,491)	(719,688)
Acquisitions of utility systems, net	(45,303)	(104,383)
Net proceeds from the sale of utility systems and other assets	634	797
Other	451	205
Net cash flows used in investing activities	(918,709)	(823,069)
Cash flows from financing activities:
Customers' advances and contributions in aid of construction	13,151	10,732
Repayments of customers' advances	(5,222)	(1,726)
Net proceeds (repayments) of short-term debt	(96,668)	148,235
Proceeds from long-term debt	681,203	944,882
Repayments of long-term debt	(570,634)	(521,792)
Change in cash overdraft position	(9,006)	(64,326)
Proceeds from issuance of common stock under dividend reinvestment plan	12,061	12,421
Proceeds from issuance of common stock from at-the-market sale agreement	322,983
Proceeds from exercised stock options	229	1,909
Repurchase of common stock	(3,955)	(1,056)
Dividends paid on common stock	(232,916)	(213,354)
Other	21	784
Net cash flows from financing activities	111,247	316,709
Net change in cash and cash equivalents	(2,893)	12,799
Cash and cash equivalents at beginning of period	11,398	10,567
Cash and cash equivalents at end of period	8,505	23,366
Non-cash investing activities:
Property, plant and equipment additions purchased at the period end, but not yet paid for	106,150	97,777
Non-cash utility property contributions	$ 36,913	$ 21,736