Segment Reporting - Reconciliation of Financial Measures of Segments to Consolidated Totals (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Revenues from external customers	$ 88,647	$ 80,490	$ 173,591	$ 157,148
Net investment income (loss)	274	146	608	314
Total revenues	88,921	80,636	174,199	157,462
Adjusted operating income (loss)	4,481	5,002	8,851	9,609
Operating Segments | Health Care Benefits
Segment Reporting Information [Line Items]
Revenues from external customers	26,521	22,633	52,213	45,618
Net investment income (loss)	205	88	369	177
Total revenues	26,747	22,741	52,624	45,835
Adjusted operating income (loss)	1,541	1,923	3,365	3,784
Operating Segments | Health Services
Segment Reporting Information [Line Items]
Revenues from external customers	43,032	39,946	83,843	76,257
Net investment income (loss)	0	0	0	0
Total revenues	46,215	42,938	90,806	82,553
Adjusted operating income (loss)	1,894	1,830	3,574	3,301
Copayments	3,400	3,100	7,500	6,900
Operating Segments | Pharmacy & Consumer Wellness
Segment Reporting Information [Line Items]
Revenues from external customers	19,079	17,877	37,505	35,208
Net investment income (loss)	1	(18)	(2)	(34)
Total revenues	28,784	26,746	56,706	52,644
Adjusted operating income (loss)	1,413	1,710	2,547	3,283
Corporate/ Other
Segment Reporting Information [Line Items]
Revenues from external customers	15	34	30	65
Net investment income (loss)	68	76	241	171
Total revenues	83	110	271	236
Adjusted operating income (loss)	(367)	(461)	(635)	(759)
Intersegment Eliminations
Segment Reporting Information [Line Items]
Intersegment revenues	(12,908)	(11,899)	(26,208)	(23,806)
Net investment income (loss)	0	0	0	0
Total revenues	(12,908)	(11,899)	(26,208)	(23,806)
Adjusted operating income (loss)	0	0	0	0
Intersegment Eliminations | Health Care Benefits
Segment Reporting Information [Line Items]
Intersegment revenues	21	20	42	40
Intersegment Eliminations | Health Services
Segment Reporting Information [Line Items]
Intersegment revenues	3,183	2,992	6,963	6,296
Intersegment Eliminations | Pharmacy & Consumer Wellness
Segment Reporting Information [Line Items]
Intersegment revenues	$ 9,704	$ 8,887	$ 19,203	$ 17,470