Segment Reporting - Retrospective Adjustments to Segment Composition (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	$ 88,921	$ 80,636	$ 174,199	$ 157,462
Adjusted operating income (loss)	4,481	5,002	8,851	9,609
Corporate/ Other
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	83	110	271	236
Adjusted operating income (loss)	(367)	(461)	(635)	(759)
Intersegment Eliminations
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	(12,908)	(11,899)	(26,208)	(23,806)
Adjusted operating income (loss)	0	0	0	0
Health Care Benefits | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	26,747	22,741	52,624	45,835
Adjusted operating income (loss)	1,541	1,923	3,365	3,784
Health Services | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	46,215	42,938	90,806	82,553
Adjusted operating income (loss)	1,894	1,830	3,574	3,301
Pharmacy & Consumer Wellness | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	28,784	26,746	56,706	52,644
Adjusted operating income (loss)	$ 1,413	1,710	$ 2,547	3,283
As Reported
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		80,636		157,462
Adjusted operating income (loss)		4,810		9,293
As Reported | Corporate/ Other
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		110		236
Adjusted operating income (loss)		(555)		(860)
As Reported | Intersegment Eliminations
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		(11,328)		(22,616)
Adjusted operating income (loss)		(183)		(387)
As Reported | Health Care Benefits | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		22,756		45,865
Adjusted operating income (loss)		1,831		3,582
As Reported | Health Services | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		42,812		82,273
Adjusted operating income (loss)		1,855		3,491
As Reported | Pharmacy & Consumer Wellness | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		26,286		51,704
Adjusted operating income (loss)		1,862		3,467
Adjustments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		0		0
Adjusted operating income (loss)		192		316
Adjustments | Corporate/ Other
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		0		0
Adjusted operating income (loss)		94		101
Adjustments | Intersegment Eliminations
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		(571)		(1,190)
Adjusted operating income (loss)		183		387
Adjustments | Health Care Benefits | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		(15)		(30)
Adjusted operating income (loss)		92		202
Adjustments | Health Services | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		126		280
Adjusted operating income (loss)		(25)		(190)
Adjustments | Pharmacy & Consumer Wellness | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		460		940
Adjusted operating income (loss)		$ (152)		$ (184)