VARIABLE INTEREST ENTITES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Variable Interest Entity [Line Items]
Restricted cash and cash equivalents	$ 23,107	$ 20,542
Accounts receivable, net	461,631	408,448
Assets	8,853,084	8,425,571
Current maturities of securitized utility tariff bonds, net of issuance costs	30,566	28,956
Accounts payable	222,102	261,321
Paid-in capital	2,530,137	2,294,469
Liabilities and Equity	8,853,084	8,425,571
Kansas Gas Service Securitization I LLC
Variable Interest Entity [Line Items]
Restricted cash and cash equivalents	23,107	20,542
Accounts receivable, net	4,463	4,659
Finite-Lived Intangible Assets, Net	233,786	265,951
Assets	261,356	291,152
Current maturities of securitized utility tariff bonds, net of issuance costs	30,566	28,956
Accounts payable	136	319
Interest Payable	5,894	6,568
Securitized utility tariff bonds	223,020	253,568
Discounts and issuance costs for securitized utility tariff bonds, excluding current maturities	4,300	4,800
Paid-in capital	1,680	1,681
Retained Earnings, Unappropriated	60	60
Liabilities and Equity	261,356	291,152
Revenues	47,446	44,390	$ 48,677
Utilities Operating Expense	(442)	(443)	(440)
Depreciation and amortization	(32,164)	(27,668)	(30,219)
Interest Income	551	671	696
Interest Expense	(15,246)	(16,806)	(18,552)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	145	144	162
Variable Interest Entity, Measure of Activity, Income Tax	0	(26)	26
Variable Interest Entity, Measure of Activity, Net Income	145	$ 118	$ 188
Finite-Lived Intangible Asset, Expected Amortization, Year One	30,271
Finite-Lived Intangible Asset, Expected Amortization, Year Two	31,996
Finite-Lived Intangible Asset, Expected Amortization, Year Three	33,818
Finite-Lived Intangible Asset, Expected Amortization, Year Five	37,770
Finite-Lived Intangible Asset, Expected Amortization, Year Four	35,740
Finite-Lived Intangible Asset, Expected Amortization, after Year Five	$ 64,191