Segment Reporting - Reconciliation of Financial Measures of Segments to Consolidated Totals (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Revenues from external customers	$ 80,958	$ 73,548	$ 238,106	$ 214,675
Net investment income (loss)	201	246	515	832
Total revenues	81,159	73,794	238,621	215,507
Adjusted operating income (loss)	4,233	4,073	13,526	13,165
Health Care Benefits
Segment Reporting Information [Line Items]
Total revenues	22,511	20,479	68,376	61,487
Pharmacy Services
Segment Reporting Information [Line Items]
Total revenues	43,216	39,046	125,489	113,681
Retail/ LTC
Segment Reporting Information [Line Items]
Total revenues	26,706	24,992	78,410	72,994
Operating Segments | Health Care Benefits
Segment Reporting Information [Line Items]
Revenues from external customers	22,387	20,311	68,029	60,993
Net investment income (loss)	101	147	278	432
Total revenues	22,511	20,479	68,376	61,487
Adjusted operating income (loss)	1,544	1,106	5,126	4,502
Operating Segments | Pharmacy Services
Segment Reporting Information [Line Items]
Revenues from external customers	40,545	36,851	116,600	105,909
Net investment income (loss)	0	0	0	0
Total revenues	43,216	39,046	125,489	113,681
Adjusted operating income (loss)	1,877	1,773	5,368	5,035
Copayments	2,900	2,800	9,800	9,000
Operating Segments | Retail/ LTC
Segment Reporting Information [Line Items]
Revenues from external customers	17,994	16,347	53,380	47,672
Net investment income (loss)	(10)	(33)	(44)	13
Total revenues	26,706	24,992	78,410	72,994
Adjusted operating income (loss)	1,398	1,723	4,865	5,166
Intersegment Eliminations
Segment Reporting Information [Line Items]
Intersegment revenues	(11,416)	(10,894)	(34,032)	(33,143)
Net investment income (loss)	0	0	0	0
Total revenues	(11,416)	(10,894)	(34,032)	(33,143)
Adjusted operating income (loss)	(169)	(186)	(556)	(523)
Intersegment Eliminations | Health Care Benefits
Segment Reporting Information [Line Items]
Intersegment revenues	23	21	69	62
Intersegment Eliminations | Pharmacy Services
Segment Reporting Information [Line Items]
Intersegment revenues	2,671	2,195	8,889	7,772
Intersegment Eliminations | Retail/ LTC
Segment Reporting Information [Line Items]
Intersegment revenues	8,722	8,678	25,074	25,309
Corporate/ Other
Segment Reporting Information [Line Items]
Revenues from external customers	32	39	97	101
Net investment income (loss)	110	132	281	387
Total revenues	142	171	378	488
Adjusted operating income (loss)	$ (417)	$ (343)	$ (1,277)	$ (1,015)