STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating activities
Net income	$ 222,850	$ 231,232	$ 221,742
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	296,699	279,830	228,479
Deferred income taxes	106,522	24,773	(22,034)
Share-based compensation expense	13,733	12,184	10,741
Provision for doubtful accounts	6,705	9,698	6,003
Proceeds from Securitization Bonds, Operating Activities	0	197,366	1,330,582
Changes in assets and liabilities:
Accounts receivable	(67,289)	196,272	(213,656)
Materials and supplies	(14,013)	(6,776)	(15,981)
Proceeds from Income Tax Refunds	(49,677)	(3,947)	0
Natural gas in storage	25,913	82,108	(89,559)
Payments for Removal Costs	(58,952)	(62,023)	(47,032)
Accounts payable	(15,014)	(90,046)	85,915
Accrued taxes other than income	6,815	(9,559)	11,317
Customer deposits	(5,944)	4,333	(4,600)
Increase (Decrease) In Regulatory Assets And Liabilities Current, net	(90,829)	7,249	52,417
Increase (Decrease) In Regulatory Assets And Liabilities Noncurrent, net	19,354	38,869	53,992
Increase (Decrease) in Other Current Assets and Liabilities, Net	(17,091)	30,017	(23,377)
Increase (Decrease) in Other Noncurrent Assets and Liabilities, Net	(11,371)	(2,048)	(14,107)
Cash provided by operating activities	368,411	939,532	1,570,842
Investing activities
Capital expenditures	(703,165)	(666,634)	(609,486)
Payments for Other Investing Activities	(10,402)	(8,508)	(8,632)
Proceeds from Sale of Other Assets, Investing Activities	6,072	5,499	4,008
Cash used in investing activities	(707,495)	(669,643)	(614,110)
Financing activities
Borrowings (repayments) of short-term debt, net	826,100	(463,500)	58,000
Proceeds from Issuance of Senior Long-Term Debt	253,467	299,583	297,591
Issuance of securitized utility tariff bonds, net of discounts	0	0	335,931
Payments of Debt Issuance Costs	(2,193)	(2,508)	(8,567)
Repayments of Other Long-Term Debt	(773,013)	0	1,627,000
Repayment of securitized utility tariff bonds	(27,939)	(20,716)	0
Proceeds from Issuance of Common Stock	252,379	85,259	133,711
Dividends paid	(149,456)	(144,094)	(133,954)
Payment, Tax Withholding, Share-based Payment Arrangement	(1,111)	(2,653)	(3,169)
Cash used in financing activities	378,234	(248,629)	(947,457)
Change in cash and cash equivalents	39,150	21,260	9,275
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Beginning Balance	39,387	18,127	8,852
Cash, cash equivalents, restricted cash and restricted cash equivalents at end of period	78,537	39,387	18,127
Interest Paid, Excluding Capitalized Interest	148,987	80,726	84,871
Income Tax Paid, State and Local, after Refund Received	366	769	621
Income Tax Paid, Oklahoma, after Refund Received	(4,546)	1,571	5,300
Income Tax Paid, Federal, after Refund Received	$ (16,280)	$ 18,504	$ 61,500