Document and Entity Information Document - shares	9 Months Ended
	Sep. 30, 2021	Oct. 29, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	1-10864
Entitiy Registrant Name	UnitedHealth Group Incorporated
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	41-1321939
Entity Address, Address Line One	UnitedHealth Group Center
Entity Address, Address Line Two	9900 Bren Road East
Entity Address, City or Town	Minnetonka,
Entity Address, State or Province	MN
Entity Address, Postal Zip Code	55343
City Area Code	952
Local Phone Number	936-1300
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Title of 12(b) Security	Common Stock, $.01 par value
Trading Symbol	UNH
Security Exchange Name	NYSE
Entitiy Central Index Key	0000731766
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		941,851,250