Segment Reporting - Reconciliation of Financial Measures of Segments to Consolidated Totals (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Revenues from external customers	$ 321,629	$ 290,912	$ 267,908
Net investment income (loss)	838	1,199	798
Total revenues	322,467	292,111	268,706
Adjusted operating income (loss)	17,532	17,312	16,008
Depreciation and amortization	4,247	4,512	4,441
Operating Segments | Health Care Benefits
Segment Reporting Information [Line Items]
Revenues from external customers	90,844	81,515	74,926
Net investment income (loss)	476	586	483
Total revenues	91,409	82,186	75,467
Adjusted operating income (loss)	5,984	5,012	6,188
Depreciation and amortization	1,629	1,837	1,832
Operating Segments | Pharmacy Services
Segment Reporting Information [Line Items]
Revenues from external customers	157,787	143,194	132,663
Net investment income (loss)	0	0	0
Total revenues	169,236	153,022	141,938
Adjusted operating income (loss)	7,356	6,859	5,688
Depreciation and amortization	567	576	612
Copayments	12,600	11,600	10,900
Operating Segments | Retail/ LTC
Segment Reporting Information [Line Items]
Revenues from external customers	72,874	66,078	60,208
Net investment income (loss)	(44)	17	0
Total revenues	106,594	100,105	91,198
Adjusted operating income (loss)	6,705	7,623	6,146
Depreciation and amortization	1,813	1,884	1,801
Intersegment Eliminations
Segment Reporting Information [Line Items]
Intersegment revenues	(45,302)	(43,923)	(40,323)
Net investment income (loss)	0	0	0
Total revenues	(45,302)	(43,923)	(40,323)
Adjusted operating income (loss)	(728)	(711)	(708)
Depreciation and amortization	0	0	0
Intersegment Eliminations | Health Care Benefits
Segment Reporting Information [Line Items]
Intersegment revenues	89	85	58
Intersegment Eliminations | Pharmacy Services
Segment Reporting Information [Line Items]
Intersegment revenues	11,449	9,828	9,275
Intersegment Eliminations | Retail/ LTC
Segment Reporting Information [Line Items]
Intersegment revenues	33,764	34,010	30,990
Corporate/ Other
Segment Reporting Information [Line Items]
Revenues from external customers	124	125	111
Net investment income (loss)	406	596	315
Total revenues	530	721	426
Adjusted operating income (loss)	(1,785)	(1,471)	(1,306)
Depreciation and amortization	$ 238	$ 215	$ 196