INCOME TAXES (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Mar. 31, 2025
Income Tax Disclosure [Abstract]
Current Federal Tax Expense (Benefit)	$ (68,660,000)	$ 16,551,000	$ 61,745,000
Current State and Local Tax Expense (Benefit)	(1,476,000)	(829,000)	6,815,000
Income Tax Expense (Benefit)	(70,136,000)	15,722,000	68,560,000
Deferred Federal Income Tax Expense (Benefit)	110,717,000	21,905,000	(22,234,000)
Deferred State and Local Income Tax Expense (Benefit)	(4,195,000)	2,868,000	200,000
Deferred Income Taxes and Tax Credits	106,522,000	24,773,000	(22,034,000)
Income Tax Expense (Benefit)	36,386,000	40,495,000	46,526,000
Reduction in income tax expense for the amortization of the regulatory liability associated with excess ADIT that was returned to customers	25,700,000	22,400,000
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits	0	0
Deferred Tax Assets, Regulatory adjustments	100,718,000	107,948,000
Deferred Tax Assets, Operating Loss Carryforwards	405,316,000	93,255,000
Deferred Tax Assets, Leasing Arrangements	3,669,000	4,500,000
Deferred Tax Assets, Regulatory Assets - purchased-gas cost adjustment	0	5,232,000
Deferred Tax Assets, Other	0	0
Deferred Tax Assets, Gross	509,703,000	210,935,000
Deferred Tax Liabilities, Property, Plant and Equipment	930,680,000	822,619,000
Deferred Tax Liabilities, Winter weather events	381,818,000	56,914,000
Deferred Tax Liabilities, Regulatory Liabilities - purchased-gas cost adjustment	8,654,000	0
Deferred Tax Liabilities, Regulatory Assets and Liabilities - other	73,904,000	70,384,000
Deferred Tax Liabilities, Tax Deferred Expense, Compensation and Benefits	934,000	205,000
Deferred Tax Liabilities, Leasing Arrangements	3,866,000	4,662,000
Deferred Tax Liabilities, Other	1,585,000	8,219,000
Deferred Tax Liabilities, Gross	1,401,441,000	963,003,000
Deferred income taxes	891,738,000	752,068,000
ONGProceedsFromSecuritizationBonds			1,300,000,000
Requested refund from 2022 amended federal tax return	55,500,000
Effective Income Tax Rate Reconciliation [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	$ 259,236,000	$ 271,727,000	$ 268,268,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	21.00%
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount	$ 54,439,000	$ 57,063,000	$ 56,335,000
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount	$ 4,333,000	$ 3,834,000	$ 7,016,000
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	2.00%	1.00%	3.00%
Tax effect of permanent differences	$ 2,018,000	$ 1,860,000	$ 1,369,000
Tax effect of permanent differences, Percent	0.01	0.01	0.01
Tax effect of state income tax deduction	(209,000)	(443,000)	(1,254,000)
Tax effect of state income tax deduction, Percent	0	0	0
Amortization of EDIT Regulatory Liability	(15,680,000)	(20,565,000)	(17,986,000)
Amortization of EDIT Regulatory Liability, Percent	(0.06)	(0.08)	(0.07)
Amortization of EDIT Regulatory Liability - State Tax	(10,004,000)	(1,795,000)	0
Amortization of EDIT Regulatory Liability - State Tax, Percent	(0.04)	(0.01)	0
Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-Based Payment Arrangement, Amount	$ 1,063,000	$ 418,000	$ 350,000
Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-Based Payment Arrangement, Percent	0.00%	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount	$ 426,000	$ 123,000	$ 696,000
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent	0.00%	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Percent	14.00%	14.00%	18.00%
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards	$ 405,316,000	$ 93,255,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Future requested refund from amended Oklahoma corporate income tax return				$ 1,500,000
Domestic Tax Jurisdiction
Income Tax Disclosure [Abstract]
Deferred Tax Assets, Operating Loss Carryforwards	378,900,000
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards	378,900,000
State and Local Jurisdiction
Income Tax Disclosure [Abstract]
Deferred Tax Assets, Operating Loss Carryforwards	26,400,000
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards	$ 26,400,000