Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Revenues	$ 90,840	$ 88,647	$ 178,823	$ 173,591
Net investment income (loss)	394	274	848	608
Total revenues	91,234	88,921	179,671	174,199
Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	50,980	55,062	99,377	107,847
Front Store
Disaggregation of Revenue [Line Items]
Revenues	5,281	5,629	10,651	11,226
Premiums
Disaggregation of Revenue [Line Items]
Revenues	30,667	25,108	61,058	49,460
Other
Disaggregation of Revenue [Line Items]
Revenues	3,912	2,848	7,737	5,058
Operating Segments \| Health Care Benefits
Disaggregation of Revenue [Line Items]
Revenues	32,157	26,521	64,022	52,213
Net investment income (loss)	300	205	653	369
Total revenues	32,475	26,747	64,711	52,624
Operating Segments \| Health Care Benefits \| Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Operating Segments \| Health Care Benefits \| Front Store
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Operating Segments \| Health Care Benefits \| Premiums
Disaggregation of Revenue [Line Items]
Revenues	30,654	25,095	61,033	49,434
Operating Segments \| Health Care Benefits \| Other
Disaggregation of Revenue [Line Items]
Revenues	1,521	1,447	3,025	2,821
Operating Segments \| Health Services
Disaggregation of Revenue [Line Items]
Revenues	38,694	43,032	75,160	83,843
Net investment income (loss)	(2)	0	(2)	0
Total revenues	42,171	46,215	82,456	90,806
Operating Segments \| Health Services \| Pharmacy network
Disaggregation of Revenue [Line Items]
Total revenues	21,848	27,477	42,312	55,069
Operating Segments \| Health Services \| Mail & specialty
Disaggregation of Revenue [Line Items]
Total revenues	17,651	17,229	34,913	33,374
Operating Segments \| Health Services \| Other
Disaggregation of Revenue [Line Items]
Total revenues	2,674	1,509	5,233	2,363
Operating Segments \| Health Services \| Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	39,499	44,706	77,225	88,443
Operating Segments \| Health Services \| Front Store
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Operating Segments \| Health Services \| Premiums
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Operating Segments \| Health Services \| Other
Disaggregation of Revenue [Line Items]
Revenues	2,674	1,509	5,233	2,363
Operating Segments \| Pharmacy & Consumer Wellness
Disaggregation of Revenue [Line Items]
Revenues	19,974	19,079	39,612	37,505
Net investment income (loss)	0	1	0	(2)
Total revenues	29,838	28,784	58,563	56,706
Operating Segments \| Pharmacy & Consumer Wellness \| Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	24,013	22,614	46,797	44,394
Operating Segments \| Pharmacy & Consumer Wellness \| Front Store
Disaggregation of Revenue [Line Items]
Revenues	5,281	5,629	10,651	11,226
Operating Segments \| Pharmacy & Consumer Wellness \| Premiums
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Operating Segments \| Pharmacy & Consumer Wellness \| Other
Disaggregation of Revenue [Line Items]
Revenues	544	540	1,115	1,088
Corporate/ Other \| Corporate/ Other
Disaggregation of Revenue [Line Items]
Revenues	15	15	29	30
Net investment income (loss)	96	68	197	241
Total revenues	111	83	226	271
Corporate/ Other \| Corporate/ Other \| Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Corporate/ Other \| Corporate/ Other \| Front Store
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Corporate/ Other \| Corporate/ Other \| Premiums
Disaggregation of Revenue [Line Items]
Revenues	13	13	25	26
Corporate/ Other \| Corporate/ Other \| Other
Disaggregation of Revenue [Line Items]
Revenues	2	2	4	4
Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Net investment income (loss)	0	0	0	0
Total revenues	(13,361)	(12,908)	(26,285)	(26,208)
Intersegment Eliminations \| Pharmacy
Disaggregation of Revenue [Line Items]
Revenues	(12,532)	(12,258)	(24,645)	(24,990)
Intersegment Eliminations \| Front Store
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Intersegment Eliminations \| Premiums
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Intersegment Eliminations \| Other
Disaggregation of Revenue [Line Items]
Revenues	$ (829)	$ (650)	$ (1,640)	$ (1,218)