Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Revenues	$ 356,623	$ 321,629	$ 290,912
Net investment income (loss)	1,153	838	1,199
Total revenues	357,776	322,467	292,111
Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	223,452	205,119	184,619
Front Store
Disaggregation of Revenue [Line Items]
Revenues	22,458	22,780	21,315
Premiums
Disaggregation of Revenue [Line Items]
Revenues	99,192	85,330	76,132
Other
Disaggregation of Revenue [Line Items]
Revenues	11,521	8,400	8,846
Operating Segments | Health Care Benefits
Disaggregation of Revenue [Line Items]
Revenues	104,800	90,798	81,457
Net investment income (loss)	765	476	586
Total revenues	105,646	91,350	82,119
Operating Segments | Health Care Benefits | Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	0	0	0
Operating Segments | Health Care Benefits | Front Store
Disaggregation of Revenue [Line Items]
Revenues	0	0	0
Operating Segments | Health Care Benefits | Premiums
Disaggregation of Revenue [Line Items]
Revenues	99,144	85,274	76,064
Operating Segments | Health Care Benefits | Other
Disaggregation of Revenue [Line Items]
Revenues	5,737	5,600	5,469
Operating Segments | Health Services
Disaggregation of Revenue [Line Items]
Revenues	174,018	157,968	143,912
Net investment income (loss)	(1)	0	0
Total revenues	186,843	169,576	153,892
Operating Segments | Health Services | Pharmacy network
Disaggregation of Revenue [Line Items]
Total revenues	112,718	102,968	96,834
Operating Segments | Health Services | Mail choice
Disaggregation of Revenue [Line Items]
Total revenues	67,992	63,825	53,812
Operating Segments | Health Services | Other
Disaggregation of Revenue [Line Items]
Total revenues	6,134	2,783	3,246
Operating Segments | Health Services | Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	180,710	166,793	150,646
Operating Segments | Health Services | Front Store
Disaggregation of Revenue [Line Items]
Revenues	0	0	0
Operating Segments | Health Services | Premiums
Disaggregation of Revenue [Line Items]
Revenues	0	0	0
Operating Segments | Health Services | Other
Disaggregation of Revenue [Line Items]
Revenues	6,134	2,783	3,246
Operating Segments | Pharmacy & Consumer Wellness
Disaggregation of Revenue [Line Items]
Revenues	77,748	72,739	65,418
Net investment income (loss)	(5)	(44)	17
Total revenues	116,763	108,596	101,620
Operating Segments | Pharmacy & Consumer Wellness | Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	92,111	83,480	77,886
Operating Segments | Pharmacy & Consumer Wellness | Front Store
Disaggregation of Revenue [Line Items]
Revenues	22,458	22,780	21,315
Operating Segments | Pharmacy & Consumer Wellness | Premiums
Disaggregation of Revenue [Line Items]
Revenues	0	0	0
Operating Segments | Pharmacy & Consumer Wellness | Other
Disaggregation of Revenue [Line Items]
Revenues	2,199	2,380	2,402
Corporate/ Other | Corporate/ Other
Disaggregation of Revenue [Line Items]
Revenues	57	124	125
Net investment income (loss)	394	406	596
Total revenues	451	530	721
Corporate/ Other | Corporate/ Other | Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	0	0	0
Corporate/ Other | Corporate/ Other | Front Store
Disaggregation of Revenue [Line Items]
Revenues	0	0	0
Corporate/ Other | Corporate/ Other | Premiums
Disaggregation of Revenue [Line Items]
Revenues	48	56	68
Corporate/ Other | Corporate/ Other | Other
Disaggregation of Revenue [Line Items]
Revenues	9	68	57
Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Net investment income (loss)	0	0	0
Total revenues	(51,927)	(47,585)	(46,241)
Intersegment Eliminations | Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	(49,369)	(45,154)	(43,913)
Intersegment Eliminations | Front Store
Disaggregation of Revenue [Line Items]
Revenues	0	0	0
Intersegment Eliminations | Premiums
Disaggregation of Revenue [Line Items]
Revenues	0	0	0
Intersegment Eliminations | Other
Disaggregation of Revenue [Line Items]
Revenues	$ (2,558)	$ (2,431)	$ (2,328)