ACQUISITIONS - Additional Information (Details) - USD ($)		12 Months Ended
	Oct. 01, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Acquisitions, net of cash acquired		$ 1,329,000,000	$ 755,000,000	$ 602,000,000
Goodwill		$ 4,872,000,000	4,223,000,000	$ 3,692,000,000
Acquired finite-lived intangible assets, useful life		8 years 2 months 12 days
Franchise rights
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, useful life		20 years
Trade name
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, useful life		8 years 1 month 6 days
Immaterial Business Acquisitions
Business Acquisition [Line Items]
Acquisitions, net of cash acquired		$ 1,300,000,000	755,000,000
Goodwill		742,000,000	581,000,000
Intangible assets acquired		550,000,000	381,000,000
Immaterial Business Acquisitions | Supply Chain  Solutions
Business Acquisition [Line Items]
Goodwill		738,000,000	476,000,000
Immaterial Business Acquisitions | International Package
Business Acquisition [Line Items]
Goodwill		4,000,000	105,000,000
Immaterial Business Acquisitions | Other Expense
Business Acquisition [Line Items]
Acquisition related costs		12,000,000	25,000,000
Immaterial Business Acquisitions | Customer Relationships
Business Acquisition [Line Items]
Intangible assets acquired		$ 249,000,000	$ 177,000,000
Acquired finite-lived intangible assets, useful life		15 years	15 years
Immaterial Business Acquisitions | Franchise rights
Business Acquisition [Line Items]
Intangible assets acquired		$ 64,000,000	$ 113,000,000
Acquired finite-lived intangible assets, useful life		20 years	20 years
Immaterial Business Acquisitions | Technology
Business Acquisition [Line Items]
Intangible assets acquired		$ 165,000,000	$ 14,000,000
Acquired finite-lived intangible assets, useful life		11 years	6 years
Immaterial Business Acquisitions | Trade name
Business Acquisition [Line Items]
Intangible assets acquired		$ 45,000,000	$ 70,000,000
Acquired finite-lived intangible assets, useful life		9 years	5 years
Immaterial Business Acquisitions | Other Intangible Assets
Business Acquisition [Line Items]
Intangible assets acquired		$ 27,000,000	$ 7,000,000
Acquired finite-lived intangible assets, useful life		3 years	5 years
Roadie, Inc.
Business Acquisition [Line Items]
Goodwill	$ 375,000,000
Intangible assets acquired	231,000,000
Goodwill, expected tax deductible amount	0
Roadie, Inc. | Supply Chain  Solutions
Business Acquisition [Line Items]
Goodwill	243,000,000
Roadie, Inc. | U.S. Domestic Package
Business Acquisition [Line Items]
Goodwill	132,000,000
Roadie, Inc. | Technology
Business Acquisition [Line Items]
Intangible assets acquired	$ 145,000,000
Acquired finite-lived intangible assets, useful life	8 years
Roadie, Inc. | Trade name
Business Acquisition [Line Items]
Intangible assets acquired	$ 67,000,000
Acquired finite-lived intangible assets, useful life	10 years
Roadie, Inc. | Other Intangible Assets
Business Acquisition [Line Items]
Intangible assets acquired	$ 19,000,000
Acquired finite-lived intangible assets, useful life	8 years