CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Schedule of Condensed Consolidating Statement of Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
ScheduleOfCondensedFinancialStatements [Line Items]
Total operating revenues	$ 855	$ 1,353	$ 2,745	$ 2,321
Total costs and other	756	835	2,193	1,776
(Loss) gain on asset divestitures	(1)	0	(1)	7
Non-operating (loss) income	(23)	(35)	(72)	(77)
INCOME BEFORE INCOME TAXES	75	483	479	475
Income tax provision	(11)	(138)	(128)	(132)
NET INCOME	64	345	351	343
Eliminations
ScheduleOfCondensedFinancialStatements [Line Items]
Total operating revenues	(21)	(86)	(61)	(101)
Total costs and other	(19)	(85)	(59)	(101)
(Loss) gain on asset divestitures	0		0	0
Non-operating (loss) income	0	0	0	0
INCOME BEFORE INCOME TAXES	(2)	(1)	(2)	0
Income tax provision	0	0	0	0
NET INCOME	(2)	(1)	(2)	0
Parent | Reportable Legal Entities
ScheduleOfCondensedFinancialStatements [Line Items]
Total operating revenues	1	2	6	15
Total costs and other	90	86	265	222
(Loss) gain on asset divestitures	0		0	0
Non-operating (loss) income	(22)	(32)	(70)	(66)
INCOME BEFORE INCOME TAXES	(111)	(116)	(329)	(273)
Income tax provision	(11)	(138)	(128)	(132)
NET INCOME	(122)	(254)	(457)	(405)
Combined Unrestricted Subsidiaries | Reportable Legal Entities
ScheduleOfCondensedFinancialStatements [Line Items]
Total operating revenues	0	0	0	0
Total costs and other	13	16	47	44
(Loss) gain on asset divestitures	0		0	0
Non-operating (loss) income	(4)	(5)	(11)	(16)
INCOME BEFORE INCOME TAXES	(17)	(21)	(58)	(60)
Income tax provision	0	0	0	0
NET INCOME	(17)	(21)	(58)	(60)
Combined Restricted Subsidiaries | Reportable Legal Entities
ScheduleOfCondensedFinancialStatements [Line Items]
Total operating revenues	875	1,437	2,800	2,407
Total costs and other	672	818	1,940	1,611
(Loss) gain on asset divestitures	(1)		(1)	7
Non-operating (loss) income	3	2	9	5
INCOME BEFORE INCOME TAXES	205	621	868	808
Income tax provision	0	0	0	0
NET INCOME	$ 205	$ 621	$ 868	$ 808