Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Disaggregation of Revenue [Line Items]
Revenues	$ 94,068	$ 87,983
Net investment income	520	454
Total revenues	94,588	88,437
Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	52,507	48,397
Front Store
Disaggregation of Revenue [Line Items]
Revenues	5,243	5,370
Premiums
Disaggregation of Revenue [Line Items]
Revenues	32,820	30,391
Other
Disaggregation of Revenue [Line Items]
Revenues	3,498	3,825
Health Care Benefits
Disaggregation of Revenue [Line Items]
Revenues	34,405	31,865
Net investment income	387	353
Health Services
Disaggregation of Revenue [Line Items]
Revenues	38,096	36,466
Net investment income	14	0
Pharmacy & Consumer Wellness
Disaggregation of Revenue [Line Items]
Revenues	21,553	19,638
Net investment income	0	0
Corporate/ Other
Disaggregation of Revenue [Line Items]
Revenues	14	14
Net investment income	119	101
Operating Segments | Health Care Benefits
Disaggregation of Revenue [Line Items]
Net investment income	387	353
Total revenues	34,810	32,236
Operating Segments | Health Care Benefits | Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	0	0
Operating Segments | Health Care Benefits | Front Store
Disaggregation of Revenue [Line Items]
Revenues	0	0
Operating Segments | Health Care Benefits | Premiums
Disaggregation of Revenue [Line Items]
Revenues	32,808	30,379
Operating Segments | Health Care Benefits | Other
Disaggregation of Revenue [Line Items]
Revenues	1,615	1,504
Operating Segments | Health Services
Disaggregation of Revenue [Line Items]
Net investment income	14	0
Total revenues	43,462	40,285
Operating Segments | Health Services | Pharmacy network
Disaggregation of Revenue [Line Items]
Total revenues	23,114	20,464
Operating Segments | Health Services | Mail & specialty
Disaggregation of Revenue [Line Items]
Total revenues	18,068	17,262
Operating Segments | Health Services | Other
Disaggregation of Revenue [Line Items]
Total revenues	2,266	2,559
Operating Segments | Health Services | Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	41,182	37,726
Operating Segments | Health Services | Front Store
Disaggregation of Revenue [Line Items]
Revenues	0	0
Operating Segments | Health Services | Premiums
Disaggregation of Revenue [Line Items]
Revenues	0	0
Operating Segments | Health Services | Other
Disaggregation of Revenue [Line Items]
Revenues	2,266	2,559
Operating Segments | Pharmacy & Consumer Wellness
Disaggregation of Revenue [Line Items]
Net investment income	0	0
Total revenues	31,912	28,725
Operating Segments | Pharmacy & Consumer Wellness | Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	26,076	22,784
Operating Segments | Pharmacy & Consumer Wellness | Front Store
Disaggregation of Revenue [Line Items]
Revenues	5,243	5,370
Operating Segments | Pharmacy & Consumer Wellness | Premiums
Disaggregation of Revenue [Line Items]
Revenues	0	0
Operating Segments | Pharmacy & Consumer Wellness | Other
Disaggregation of Revenue [Line Items]
Revenues	593	571
Corporate/ Other | Corporate/ Other
Disaggregation of Revenue [Line Items]
Net investment income	119	101
Total revenues	133	115
Corporate/ Other | Corporate/ Other | Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	0	0
Corporate/ Other | Corporate/ Other | Front Store
Disaggregation of Revenue [Line Items]
Revenues	0	0
Corporate/ Other | Corporate/ Other | Premiums
Disaggregation of Revenue [Line Items]
Revenues	12	12
Corporate/ Other | Corporate/ Other | Other
Disaggregation of Revenue [Line Items]
Revenues	2	2
Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Net investment income	0	0
Total revenues	(15,729)	(12,924)
Intersegment Eliminations | Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	(14,751)	(12,113)
Intersegment Eliminations | Front Store
Disaggregation of Revenue [Line Items]
Revenues	0	0
Intersegment Eliminations | Premiums
Disaggregation of Revenue [Line Items]
Revenues	0	0
Intersegment Eliminations | Other
Disaggregation of Revenue [Line Items]
Revenues	(978)	(811)
Intersegment Eliminations | Health Care Benefits
Disaggregation of Revenue [Line Items]
Total revenues	(18)	(18)
Intersegment Eliminations | Health Services
Disaggregation of Revenue [Line Items]
Total revenues	(5,352)	(3,819)
Intersegment Eliminations | Pharmacy & Consumer Wellness
Disaggregation of Revenue [Line Items]
Total revenues	$ (10,359)	$ (9,087)