Acquisitions, Divestitures and Asset Sales - Summary of the Valuation of Goodwill Allocated to Business Segments (Details) - USD ($) $ in Millions	Dec. 31, 2023	May 02, 2023	Mar. 29, 2023	Dec. 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Goodwill	$ 91,272			$ 78,150	$ 79,121
Health Services
Business Acquisition [Line Items]
Goodwill	34,066			23,615	23,615
Pharmacy & Consumer Wellness
Business Acquisition [Line Items]
Goodwill	10,562			10,376	10,376
Health Care Benefits
Business Acquisition [Line Items]
Goodwill	$ 46,644			$ 44,159	$ 45,130
Oak Street Health Inc.
Business Acquisition [Line Items]
Goodwill		$ 7,213
Oak Street Health Inc. | Health Services
Business Acquisition [Line Items]
Goodwill		6,936
Oak Street Health Inc. | Pharmacy & Consumer Wellness
Business Acquisition [Line Items]
Goodwill		156
Oak Street Health Inc. | Health Care Benefits
Business Acquisition [Line Items]
Goodwill		$ 121
Signify Health, Inc.
Business Acquisition [Line Items]
Goodwill			$ 5,909
Signify Health, Inc. | Health Services
Business Acquisition [Line Items]
Goodwill			3,406
Signify Health, Inc. | Pharmacy & Consumer Wellness
Business Acquisition [Line Items]
Goodwill			30
Signify Health, Inc. | Health Care Benefits
Business Acquisition [Line Items]
Goodwill			$ 2,473