Segment Reporting - Retrospective Adjustments to Segment Composition (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	$ 357,776	$ 322,467	$ 292,111
Adjusted operating income	17,534	18,037	17,227
Operating Segments | Health Care Benefits
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	105,646	91,350	82,119
Adjusted operating income	5,577	6,338	5,110
Operating Segments | Health Services
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	186,843	169,576	153,892
Adjusted operating income	7,312	6,781	6,492
Operating Segments | Pharmacy & Consumer Wellness
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	116,763	108,596	101,620
Adjusted operating income	5,963	6,531	7,260
Corporate/ Other | Corporate/ Other
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	451	530	721
Adjusted operating income	(1,318)	(1,613)	(1,635)
Intersegment Eliminations
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	(51,927)	(47,585)	(46,241)
Adjusted operating income	$ 0	0	0
As Previously Reported
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		322,467	292,111
Adjusted operating income		17,532	17,312
As Previously Reported | Operating Segments | Health Care Benefits
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		91,409	82,186
Adjusted operating income		5,984	5,012
As Previously Reported | Operating Segments | Health Services
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		169,236	153,022
Adjusted operating income		7,356	6,859
As Previously Reported | Operating Segments | Pharmacy & Consumer Wellness
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		106,594	100,105
Adjusted operating income		6,705	7,623
As Previously Reported | Corporate/ Other | Corporate/ Other
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		530	721
Adjusted operating income		(1,785)	(1,471)
As Previously Reported | Intersegment Eliminations
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		(45,302)	(43,923)
Adjusted operating income		(728)	(711)
Adjustments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		0	0
Adjusted operating income		505	(85)
Adjustments | Operating Segments | Health Care Benefits
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		(59)	(67)
Adjusted operating income		354	98
Adjustments | Operating Segments | Health Services
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		340	870
Adjusted operating income		(575)	(367)
Adjustments | Operating Segments | Pharmacy & Consumer Wellness
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		2,002	1,515
Adjusted operating income		(174)	(363)
Adjustments | Corporate/ Other | Corporate/ Other
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		0	0
Adjusted operating income		172	(164)
Adjustments | Intersegment Eliminations
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		(2,283)	(2,318)
Adjusted operating income		$ 728	$ 711