Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Revenues	$ 87,983	$ 84,944
Net investment income (loss)	454	334
Total revenues	88,437	85,278
Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	48,397	52,785
Front Store
Disaggregation of Revenue [Line Items]
Revenues	5,370	5,597
Premiums
Disaggregation of Revenue [Line Items]
Revenues	30,391	24,352
Other
Disaggregation of Revenue [Line Items]
Revenues	3,825	2,210
Operating Segments | Health Care Benefits
Disaggregation of Revenue [Line Items]
Revenues	31,865	25,692
Net investment income (loss)	353	164
Total revenues	32,236	25,877
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	30,379	24,339
Operating Segments | Health Care Benefits | Other
Disaggregation of Revenue [Line Items]
Revenues	1,504	1,374
Operating Segments | Health Services
Disaggregation of Revenue [Line Items]
Revenues	36,466	40,811
Net investment income (loss)	0	0
Total revenues	40,285	44,591
Operating Segments | Health Services | Pharmacy network
Disaggregation of Revenue [Line Items]
Total revenues	20,464	27,592
Operating Segments | Health Services | Mail & specialty
Disaggregation of Revenue [Line Items]
Total revenues	17,262	16,145
Operating Segments | Health Services | Other
Disaggregation of Revenue [Line Items]
Total revenues	2,559	854
Operating Segments | Health Services | Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	37,726	43,737
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	2,559	854
Operating Segments | Pharmacy & Consumer Wellness
Disaggregation of Revenue [Line Items]
Revenues	19,638	18,426
Net investment income (loss)	0	(3)
Total revenues	28,725	27,922
Operating Segments | Pharmacy & Consumer Wellness | Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	22,784	21,780
Operating Segments | Pharmacy & Consumer Wellness | Front Store
Disaggregation of Revenue [Line Items]
Revenues	5,370	5,597
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	571	548
Corporate/ Other | Corporate/ Other
Disaggregation of Revenue [Line Items]
Revenues	14	15
Net investment income (loss)	101	173
Total revenues	115	188
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	13
Corporate/ Other | Corporate/ Other | Other
Disaggregation of Revenue [Line Items]
Revenues	2	2
Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Net investment income (loss)	0	0
Total revenues	(12,924)	(13,300)
Intersegment Eliminations | Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	(12,113)	(12,732)
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	$ (811)	$ (568)