Segment Financial Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement [Line Items]
Premiums, revenues - unaffiliated customers	$ 257,157	$ 226,233	$ 201,478
Investment and other income	2,030	2,324	1,502
Total revenues	324,162	287,597	257,141
Earnings from operations	28,435	23,970	22,405
Interest expense	(2,092)	(1,660)	(1,663)
Earnings before income taxes	26,343	22,310	20,742
Total assets	245,705	212,206	197,289
Purchases of property, equipment and capitalized software	2,802	2,454	2,051
Depreciation and amortization	3,400	3,103	2,891
Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	37,424	34,437	34,145
Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	27,551	24,603	20,016
Optum
Statement [Line Items]
Investment and other income	1,107	1,467	770
Total revenues	182,768	155,565	136,308
Earnings from operations	14,056	11,995	10,046
Interest expense	0	0	0
Earnings before income taxes	14,056	11,995	10,046
Total assets	147,516	117,523	106,778
Purchases of property, equipment and capitalized software	2,003	1,659	1,364
Depreciation and amortization	2,427	2,099	1,971
Unaffiliated Customers
Statement [Line Items]
Premiums, revenues - unaffiliated customers	257,157	226,233	201,478
Total revenues	322,132	285,273	255,639
Unaffiliated Customers | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	37,424	34,437	34,145
Unaffiliated Customers | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	27,551	24,603	20,016
Unaffiliated Customers | Optum
Statement [Line Items]
Premiums, revenues - unaffiliated customers	18,374	13,852	9,799
Total revenues	73,314	63,231	55,496
Unaffiliated Customers | Optum | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	37,424	34,437	34,145
Unaffiliated Customers | Optum | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	17,516	14,942	11,552
Affiliated Customers
Statement [Line Items]
Total revenues	0	0	0
Affiliated Customers | Optum
Statement [Line Items]
Total revenues	108,347	90,867	80,042
Operating Segments | UnitedHealthcare
Statement [Line Items]
Investment and other income	923	857	732
Total revenues	249,741	222,899	200,875
Earnings from operations	14,379	11,975	12,359
Interest expense	0	0	0
Earnings before income taxes	14,379	11,975	12,359
Total assets	107,094	102,967	98,229
Purchases of property, equipment and capitalized software	799	795	687
Depreciation and amortization	973	1,004	920
Operating Segments | Optum Health
Statement [Line Items]
Investment and other income	928	1,053	680
Total revenues	71,174	54,065	39,808
Earnings from operations	6,032	4,462	3,434
Interest expense	0	0	0
Earnings before income taxes	6,032	4,462	3,434
Total assets	68,950	60,474	52,073
Purchases of property, equipment and capitalized software	997	791	715
Depreciation and amortization	943	818	703
Operating Segments | Optum Insight
Statement [Line Items]
Investment and other income	117	237	39
Total revenues	14,581	12,199	10,802
Earnings from operations	3,588	3,398	2,725
Interest expense	0	0	0
Earnings before income taxes	3,588	3,398	2,725
Total assets	31,090	16,868	15,425
Purchases of property, equipment and capitalized software	698	567	461
Depreciation and amortization	841	684	670
Operating Segments | Optum Rx
Statement [Line Items]
Investment and other income	62	177	51
Total revenues	99,773	91,314	87,498
Earnings from operations	4,436	4,135	3,887
Interest expense	0	0	0
Earnings before income taxes	4,436	4,135	3,887
Total assets	47,476	40,181	39,280
Purchases of property, equipment and capitalized software	308	301	188
Depreciation and amortization	643	597	598
Operating Segments | Unaffiliated Customers | UnitedHealthcare
Statement [Line Items]
Premiums, revenues - unaffiliated customers	238,783	212,381	191,679
Total revenues	248,818	222,042	200,143
Operating Segments | Unaffiliated Customers | UnitedHealthcare | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	0	0	0
Operating Segments | Unaffiliated Customers | UnitedHealthcare | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	10,035	9,661	8,464
Operating Segments | Unaffiliated Customers | Optum Health
Statement [Line Items]
Premiums, revenues - unaffiliated customers	18,374	13,852	9,799
Total revenues	29,363	23,778	16,647
Operating Segments | Unaffiliated Customers | Optum Health | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	72	32	33
Operating Segments | Unaffiliated Customers | Optum Health | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	10,917	9,894	6,815
Operating Segments | Unaffiliated Customers | Optum Insight
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0
Total revenues	5,176	4,095	3,822
Operating Segments | Unaffiliated Customers | Optum Insight | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	180	159	135
Operating Segments | Unaffiliated Customers | Optum Insight | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	4,996	3,936	3,687
Operating Segments | Unaffiliated Customers | Optum Rx
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0
Total revenues	38,775	35,358	35,027
Operating Segments | Unaffiliated Customers | Optum Rx | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	37,172	34,246	33,977
Operating Segments | Unaffiliated Customers | Optum Rx | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	1,603	1,112	1,050
Operating Segments | Affiliated Customers | UnitedHealthcare
Statement [Line Items]
Total revenues	0	0	0
Operating Segments | Affiliated Customers | Optum Health
Statement [Line Items]
Total revenues	40,883	29,234	22,481
Operating Segments | Affiliated Customers | Optum Insight
Statement [Line Items]
Total revenues	9,288	7,867	6,941
Operating Segments | Affiliated Customers | Optum Rx
Statement [Line Items]
Total revenues	60,936	55,779	52,420
Optum Eliminations
Statement [Line Items]
Investment and other income	0	0	0
Total revenues	(2,760)	(2,013)	(1,800)
Earnings from operations	0	0	0
Interest expense	0	0	0
Earnings before income taxes	0	0	0
Total assets	0	0	0
Purchases of property, equipment and capitalized software	0	0	0
Depreciation and amortization	0	0	0
Optum Eliminations | Unaffiliated Customers
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0
Total revenues	0	0	0
Optum Eliminations | Unaffiliated Customers | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	0	0	0
Optum Eliminations | Unaffiliated Customers | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	0	0	0
Optum Eliminations | Affiliated Customers
Statement [Line Items]
Total revenues	(2,760)	(2,013)	(1,800)
Corporate and Eliminations
Statement [Line Items]
Investment and other income	0	0	0
Total revenues	(108,347)	(90,867)	(80,042)
Earnings from operations	0	0	0
Interest expense	(2,092)	(1,660)	(1,663)
Earnings before income taxes	(2,092)	(1,660)	(1,663)
Total assets	(8,905)	(8,284)	(7,718)
Purchases of property, equipment and capitalized software	0	0	0
Depreciation and amortization	0	0	0
Corporate and Eliminations | Unaffiliated Customers
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0
Total revenues	0	0	0
Corporate and Eliminations | Unaffiliated Customers | Products
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	0	0	0
Corporate and Eliminations | Unaffiliated Customers | Services
Statement [Line Items]
Revenue from Products and Services - unaffiliated customers	0	0	0
Corporate and Eliminations | Affiliated Customers
Statement [Line Items]
Total revenues	$ (108,347)	$ (90,867)	$ (80,042)