Basis of Presentation (Details)	3 Months Ended
Mar. 31, 2021
Nature of Operations	UnitedHealth Group Incorporated (individually and together with its subsidiaries, “UnitedHealth Group” and “the Company”) is a diversified health care company with a mission to help people live healthier lives and help make the health system work better for everyone. Our two complementary business platforms — Optum and UnitedHealthcare — are driven by this unified mission and vision to improve health care access, affordability, experiences and outcomes for the individuals and organizations we are privileged to serve.

The entire disclosure for the nature of an entity's business, major products or services, principal markets including location, and the relative importance of its operations in each business and the basis for the determination, including but not limited to, assets, revenues, or earnings. For an entity that has not commenced principal operations, disclosures about the risks and uncertainties related to the activities in which the entity is currently engaged and an understanding of what those activities are being directed toward.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e5967-108592

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-URI http://asc.fasb.org/topic&trid=2134479

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