UNCONSOLIDATED AFFILIATES - Schedule of Equity in Net Earnings from Investments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	$ 103	$ 81	$ 192	$ 189
Impairment of equity investments (Note H)	0	0	(60)	0
Northern Border
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	29	20	69	48
Overland Pass
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	24	20	48	46
Matterhorn
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	14	7	22	8
Saddlehorn
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	11	13	22	26
Roadrunner
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	10	11	20	21
BridgeTex
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	3	6	16	22
Powder Springs
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	0	(1)	(26)	2
Other
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	$ 12	$ 5	$ 21	$ 16