Segment Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement [Line Items]
Premiums, revenues - unaffiliated customers	$ 72,339	$ 64,491	$ 217,599	$ 192,457
Investment and other income	997	513	2,910	1,175
Total revenues	92,361	80,894	277,195	241,375
Earnings from operations	8,526	7,462	24,669	21,544
Interest expense	(834)	(516)	(2,416)	(1,416)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	7,692	6,946	22,253	20,128
Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	10,354	9,190	31,272	28,026
Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	8,671	6,700	25,414	19,717
Optum
Statement [Line Items]
Investment and other income	403	328	1,261	652
Total revenues	56,737	46,559	167,140	134,900
Earnings from operations	3,934	3,663	11,376	10,097
Interest expense	0	0	0	0
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	3,934	3,663	11,376	10,097
Unaffiliated Customers
Statement [Line Items]
Premiums, revenues - unaffiliated customers	72,339	64,491	217,599	192,457
Total revenues	91,364	80,381	274,285	240,200
Unaffiliated Customers | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	10,354	9,190	31,272	28,026
Unaffiliated Customers | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	8,671	6,700	25,414	19,717
Unaffiliated Customers | Optum
Statement [Line Items]
Premiums, revenues - unaffiliated customers	5,630	5,116	16,385	13,777
Total revenues	22,105	18,571	65,382	54,028
Unaffiliated Customers | Optum | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	10,354	9,190	31,272	28,026
Unaffiliated Customers | Optum | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	6,121	4,265	17,725	12,225
Affiliated Customers
Statement [Line Items]
Total revenues	0	0	0	0
Affiliated Customers | Optum
Statement [Line Items]
Total revenues	34,229	27,660	100,497	80,220
Operating Segments | UnitedHealthcare
Statement [Line Items]
Investment and other income	594	185	1,649	523
Total revenues	69,853	61,995	210,552	186,695
Earnings from operations	4,592	3,799	13,293	11,447
Interest expense	0	0	0	0
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	4,592	3,799	13,293	11,447
Operating Segments | Optum Health
Statement [Line Items]
Investment and other income	317	287	1,038	528
Total revenues	23,864	18,463	70,785	52,728
Earnings from operations	1,568	1,575	4,869	4,340
Interest expense	0	0	0	0
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	1,568	1,575	4,869	4,340
Operating Segments | Optum Insight
Statement [Line Items]
Investment and other income	35	23	80	99
Total revenues	4,977	3,693	14,147	10,194
Earnings from operations	1,109	1,007	2,984	2,693
Interest expense	0	0	0	0
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	1,109	1,007	2,984	2,693
Operating Segments | Optum Rx
Statement [Line Items]
Investment and other income	51	18	143	25
Total revenues	28,857	25,203	84,921	73,919
Earnings from operations	1,257	1,081	3,523	3,064
Interest expense	0	0	0	0
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	1,257	1,081	3,523	3,064
Operating Segments | Unaffiliated Customers | UnitedHealthcare
Statement [Line Items]
Premiums, revenues - unaffiliated customers	66,709	59,375	201,214	178,680
Total revenues	69,259	61,810	208,903	186,172
Operating Segments | Unaffiliated Customers | UnitedHealthcare | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	0	0	0	0
Operating Segments | Unaffiliated Customers | UnitedHealthcare | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	2,550	2,435	7,689	7,492
Operating Segments | Unaffiliated Customers | Optum Health
Statement [Line Items]
Premiums, revenues - unaffiliated customers	5,630	5,116	16,385	13,777
Total revenues	9,320	7,874	26,800	21,845
Operating Segments | Unaffiliated Customers | Optum Health | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	61	2	156	14
Operating Segments | Unaffiliated Customers | Optum Health | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	3,629	2,756	10,259	8,054
Operating Segments | Unaffiliated Customers | Optum Insight
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0	0
Total revenues	1,978	1,104	5,978	3,210
Operating Segments | Unaffiliated Customers | Optum Insight | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	40	37	119	135
Operating Segments | Unaffiliated Customers | Optum Insight | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	1,938	1,067	5,859	3,075
Operating Segments | Unaffiliated Customers | Optum Rx
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0	0
Total revenues	10,807	9,593	32,604	28,973
Operating Segments | Unaffiliated Customers | Optum Rx | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	10,253	9,151	30,997	27,877
Operating Segments | Unaffiliated Customers | Optum Rx | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	554	442	1,607	1,096
Operating Segments | Affiliated Customers | UnitedHealthcare
Statement [Line Items]
Total revenues	0	0	0	0
Operating Segments | Affiliated Customers | Optum Health
Statement [Line Items]
Total revenues	14,227	10,302	42,947	30,355
Operating Segments | Affiliated Customers | Optum Insight
Statement [Line Items]
Total revenues	2,964	2,566	8,089	6,885
Operating Segments | Affiliated Customers | Optum Rx
Statement [Line Items]
Total revenues	17,999	15,592	52,174	44,921
Optum Eliminations
Statement [Line Items]
Investment and other income	0	0	0	0
Total revenues	(961)	(800)	(2,713)	(1,941)
Earnings from operations	0	0	0	0
Interest expense	0	0	0	0
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	0	0	0	0
Optum Eliminations | Unaffiliated Customers
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0	0
Total revenues	0	0	0	0
Optum Eliminations | Unaffiliated Customers | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	0	0	0	0
Optum Eliminations | Unaffiliated Customers | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	0	0	0	0
Optum Eliminations | Affiliated Customers
Statement [Line Items]
Total revenues	(961)	(800)	(2,713)	(1,941)
Corporate and Eliminations
Statement [Line Items]
Investment and other income	0	0	0	0
Total revenues	(34,229)	(27,660)	(100,497)	(80,220)
Earnings from operations	0	0	0	0
Interest expense	(834)	(516)	(2,416)	(1,416)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	(834)	(516)	(2,416)	(1,416)
Corporate and Eliminations | Unaffiliated Customers
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0	0
Total revenues	0	0	0	0
Corporate and Eliminations | Unaffiliated Customers | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	0	0	0	0
Corporate and Eliminations | Unaffiliated Customers | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	0	0	0	0
Corporate and Eliminations | Affiliated Customers
Statement [Line Items]
Total revenues	$ (34,229)	$ (27,660)	$ (100,497)	$ (80,220)