Segment Reporting - Retrospective Adjustments to Segment Composition (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	$ 85,278	$ 76,826
Adjusted operating income (loss)	4,370	4,607
Corporate/ Other
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	188	126
Adjusted operating income (loss)	(268)	(298)
Intersegment Eliminations
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	(13,300)	(11,907)
Adjusted operating income (loss)	0	0
Health Care Benefits | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	25,877	23,094
Adjusted operating income (loss)	1,824	1,861
Health Services | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	44,591	39,615
Adjusted operating income (loss)	1,680	1,471
Pharmacy & Consumer Wellness | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues	27,922	25,898
Adjusted operating income (loss)	$ 1,134	1,573
As Reported
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		76,826
Adjusted operating income (loss)		4,483
As Reported | Corporate/ Other
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		126
Adjusted operating income (loss)		(305)
As Reported | Intersegment Eliminations
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		(11,288)
Adjusted operating income (loss)		(204)
As Reported | Health Care Benefits | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		23,109
Adjusted operating income (loss)		1,751
As Reported | Health Services | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		39,461
Adjusted operating income (loss)		1,636
As Reported | Pharmacy & Consumer Wellness | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		25,418
Adjusted operating income (loss)		1,605
Adjustments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		0
Adjusted operating income (loss)		124
Adjustments | Corporate/ Other
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		0
Adjusted operating income (loss)		7
Adjustments | Intersegment Eliminations
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		(619)
Adjusted operating income (loss)		204
Adjustments | Health Care Benefits | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		(15)
Adjusted operating income (loss)		110
Adjustments | Health Services | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		154
Adjusted operating income (loss)		(165)
Adjustments | Pharmacy & Consumer Wellness | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenues		480
Adjusted operating income (loss)		$ (32)