Segment Reporting - Reconciliation of Financial Measures of Segments to Consolidated Totals (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Revenues from external customers	$ 356,623	$ 321,629	$ 290,912
Net investment income (loss)	1,153	838	1,199
Total revenues	357,776	322,467	292,111
Adjusted operating income (loss)	17,534	18,037	17,227
Depreciation and amortization	4,366	4,224	4,486
Operating Segments | Health Care Benefits
Segment Reporting Information [Line Items]
Revenues from external customers	104,800	90,798	81,457
Net investment income (loss)	765	476	586
Total revenues	105,646	91,350	82,119
Adjusted operating income (loss)	5,577	6,338	5,110
Depreciation and amortization	1,572	1,579	1,811
Operating Segments | Health Services
Segment Reporting Information [Line Items]
Revenues from external customers	174,018	157,968	143,912
Net investment income (loss)	(1)	0	0
Total revenues	186,843	169,576	153,892
Adjusted operating income (loss)	7,312	6,781	6,492
Depreciation and amortization	880	519	505
Copayments	13,700	12,600	11,600
Operating Segments | Pharmacy & Consumer Wellness
Segment Reporting Information [Line Items]
Revenues from external customers	77,748	72,739	65,418
Net investment income (loss)	(5)	(44)	17
Total revenues	116,763	108,596	101,620
Adjusted operating income (loss)	5,963	6,531	7,260
Depreciation and amortization	1,549	1,889	1,955
Intersegment Eliminations
Segment Reporting Information [Line Items]
Intersegment revenues	(51,927)	(47,585)	(46,241)
Net investment income (loss)	0	0	0
Total revenues	(51,927)	(47,585)	(46,241)
Adjusted operating income (loss)	0	0	0
Depreciation and amortization	0	0	0
Intersegment Eliminations | Health Care Benefits
Segment Reporting Information [Line Items]
Intersegment revenues	81	76	76
Intersegment Eliminations | Health Services
Segment Reporting Information [Line Items]
Intersegment revenues	12,826	11,608	9,980
Intersegment Eliminations | Pharmacy & Consumer Wellness
Segment Reporting Information [Line Items]
Intersegment revenues	39,020	35,901	36,185
Corporate/ Other | Corporate/ Other
Segment Reporting Information [Line Items]
Revenues from external customers	57	124	125
Net investment income (loss)	394	406	596
Total revenues	451	530	721
Adjusted operating income (loss)	(1,318)	(1,613)	(1,635)
Depreciation and amortization	$ 365	$ 237	$ 215