Document and Entity Information Document - USD ($)	12 Months Ended
	Dec. 31, 2018	Jan. 31, 2019	Jun. 30, 2018
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Entitiy Registrant Name	UNITEDHEALTH GROUP INC
Entitiy Central Index Key	0000731766
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Well known seasoned issuer	Yes
Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		959,538,515
Closing Share Price			$ 245.34
Public Float			$ 234,490,429,732