SEGMENT REPORTING - Other Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Segment Reporting Information [Line Items]
Depreciation expense and other non-cash charges, net	$ 555	$ 536	$ 1,670	$ 1,652
Interest expense	102	98	304	286
Purchases of property and revenue earning equipment	527	599	1,730	1,922
Operating Segments | FMS
Segment Reporting Information [Line Items]
Depreciation expense and other non-cash charges, net	435	426	1,316	1,306
Interest expense	95	92	284	268
Purchases of property and revenue earning equipment	464	576	1,601	1,866
Operating Segments | SCS
Segment Reporting Information [Line Items]
Depreciation expense and other non-cash charges, net	101	94	295	281
Interest expense	5	4	14	12
Purchases of property and revenue earning equipment	58	15	115	45
Operating Segments | DTS
Segment Reporting Information [Line Items]
Depreciation expense and other non-cash charges, net	3	6	14	28
Interest expense	2	2	6	6
Purchases of property and revenue earning equipment	1	0	2	1
Segment Reconciling Items
Segment Reporting Information [Line Items]
Depreciation expense and other non-cash charges, net	16	10	45	37
Interest expense	0	0	0	0
Purchases of property and revenue earning equipment	$ 4	$ 8	$ 12	$ 10