Consolidated Statements Of Cash Flow - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net income	$ 51,781	$ 16,924
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	46,245	39,410
Deferred income taxes	(18,701)	(8,852)
Provision for doubtful accounts	2,204	803
Stock-based compensation	1,688	1,930
Gain on sale of other assets	(105)	(220)
Interest rate swap agreements		34,782
Net change in receivables, inventory and prepayments	22,921	2,263
Net change in payables, accrued interest, accrued taxes and other accrued liabilities	(7,531)	(3,402)
Pension and other postretirement benefits contributions	(36)	(3,947)
Other	(2,945)	(404)
Net cash flows from operating activities	95,521	79,287
Cash flows from investing activities:
Property, plant and equipment additions, including the debt component of allowance for funds used during construction of $873 and $1,030	(118,734)	(133,792)
Acquisitions of utility systems, net	(3,446,056)	(469)
Net proceeds from the sale of other assets	160	242
Other	28	462
Net cash flows used in investing activities	(3,564,602)	(133,557)
Cash flows from financing activities:
Customers' advances and contributions in aid of construction	1,462	1,858
Repayments of customers' advances	(1,065)	(765)
Net proceeds of short-term debt	174,281	17,114
Proceeds from long-term debt	801,184	117,995
Repayments of long-term debt	(11,509)	(41,976)
Change in cash overdraft position	(10,943)	(3,856)
Issuance of common stock under dividend reinvestment plan	4,062	4,035
Issuance of common stock from private placement	730,135
Proceeds from exercised stock options	950	1,175
Repurchase of common stock	(4,339)	(1,857)
Dividends paid on common stock	(52,205)	(39,014)
Other	(6)	(13)
Net cash flows from financing activities	1,632,007	54,696
Net change in cash and cash equivalents	(1,837,074)	426
Cash and cash equivalents at beginning of period	1,868,922	3,627
Cash and cash equivalents at end of period	31,848	4,053
Non-cash investing activities:
Property, plant and equipment additions purchased at the period end, but not yet paid for	55,881	42,594
Non-cash customer advances and contributions in aid of construction	$ 8,637	$ 17,331