REGULATORY ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Feb. 28, 2021
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	$ 94,692		$ 75,308
Regulatory Assets, Noncurrent	283,851		287,906
Regulatory Assets	378,543		363,214
Regulatory Liability, Current	(34,844)		(66,901)
Regulatory Liability, Noncurrent	(487,475)		(500,478)
Regulatory Liabilities	(522,319)		(567,379)
Net regulatory assets (liabilities), current	59,848		8,407
Net regulatory assets (liabilities), noncurrent	(203,624)		(212,572)
Net Regulatory Assets	(143,776)		(204,165)
February 2021 Natural Gas Purchases				$ 2,100,000
TGS Proceeds from Securitization Bonds		$ 197,000
Amortization of Rate Deferral	7,100	$ 7,000
West Texas Service Area
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
TGS Deferred Extraordinary Costs from 2021 Winter Storm Uri	17,400
Income tax rate changes [Member] [Domain]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Liability, Current	0		0
Regulatory Liability, Noncurrent	(487,475)		(500,478)
Regulatory Liabilities	(487,475)		(500,478)
Over-recovered purchased-gas costs [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Liability, Current	(34,844)		(66,901)
Regulatory Liability, Noncurrent	0		0
Regulatory Liabilities	(34,844)		(66,901)
Winter weather event costs
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	17,390		22,633
Regulatory Assets, Noncurrent	17,433		21,495
Regulatory Assets	34,823		44,128
Under-recovered purchased-gas costs [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	29,465		10,391
Regulatory Assets, Noncurrent	0		0
Regulatory Assets	29,465		10,391
Pension and postretirement benefit costs [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	1,601		6,379
Regulatory Assets, Noncurrent	229,014		228,092
Regulatory Assets	230,615		234,471
Reacquired debt costs [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	723		723
Regulatory Assets, Noncurrent	2,531		2,712
Regulatory Assets	3,254		3,435
MGP Costs [Member] [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	98		98
Regulatory Assets, Noncurrent	30,387		31,893
Regulatory Assets	30,485		31,991
Ad valorem tax [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	12,085		14,533
Regulatory Assets, Noncurrent	0		0
Regulatory Assets	12,085		14,533
Weather normalization [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	16,207		11,404
Regulatory Assets, Noncurrent	0		0
Regulatory Assets	16,207		11,404
Customer credit deferrals
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	12,833		6,184
Regulatory Assets, Noncurrent	1,177		0
Regulatory Assets	14,010		6,184
Other regulatory assets [Member]
SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]
Regulatory Assets, Current	4,290		2,963
Regulatory Assets, Noncurrent	3,309		3,714
Regulatory Assets	$ 7,599		$ 6,677