Basis of Presentation	9 Months Ended
Sep. 30, 2012
Accounting Policies [Abstract]
Basis of Presentation [Text Block]	Basis of Presentation UnitedHealth Group Incorporated (also referred to as “UnitedHealth Group” and the “Company”) is a diversified health and well-being company dedicated to helping people live healthier lives and making health care work better. We offer a broad spectrum of products and services through two distinct platforms: UnitedHealthcare, which provides health care coverage and benefits services; and Optum, which provides information and technology-enabled health services. The Company has prepared the Condensed Consolidated Financial Statements according to U.S. Generally Accepted Accounting Principles (GAAP) and has included the accounts of UnitedHealth Group and its subsidiaries. The Company has eliminated intercompany balances and transactions. The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. In accordance with the rules and regulations of the U.S. Securities and Exchange Commission (SEC), the Company has omitted certain footnote disclosures that would substantially duplicate the disclosures contained in its annual audited Consolidated Financial Statements. Therefore, these Condensed Consolidated Financial Statements should be read together with the Consolidated Financial Statements and the Notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2011 as filed with the SEC (2011 10-K). The accompanying Condensed Consolidated Financial Statements include all normal recurring adjustments necessary to present the interim financial statements fairly. Use of Estimates These Condensed Consolidated Financial Statements include certain amounts based on the Company’s best estimates and judgments. The Company’s most significant estimates relate to medical costs payable and medical costs, premium rebates and risk-adjustment and risk-sharing provisions related to revenues, valuation and impairment analysis of goodwill and other intangible assets, estimates of other policy liabilities and other current receivables, valuations of investments, income taxes and contingent liabilities. These estimates require the application of complex assumptions and judgments, often because they involve matters that are inherently uncertain and will likely change in subsequent periods. The impact of any changes in estimates is included in earnings in the period in which the estimate is adjusted. Accounting Policies Following is an expanded portion of the Company's revenue policy related to premium rebates. All other accounting policies disclosed in Note 2 of Notes to the Consolidated Financial Statements in the 2011 10-K remain unchanged. The Company's fully insured commercial premium revenues are generally subject to the minimum medical loss ratio requirements of the Patient Protection and Affordable Care Act and the associated reconciliation measure, the Health Care and Education Reconciliation Act of 2010 (Health Reform Legislation). Premium revenues are recognized based on the estimated premiums earned net of projected rebates because the Company is able to reasonably estimate the ultimate premiums of these contracts. Each period, the Company estimates premium rebates based on the expected financial performance of the applicable contracts within each defined aggregation set (e.g., by state, group size and licensed subsidiary). The most significant factors in estimating the financial performance are current and future premiums and medical claim experience, effective tax rates and expected changes in business mix. The estimated ultimate premium is revised each period to reflect current and projected experience. Recently Adopted Accounting Standards In May 2011, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2011-04, “Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRSs” (ASU 2011-04). This update provides guidance on how fair value measurement should be applied where existing GAAP already requires or permits fair value measurements. In addition, ASU 2011-04 requires expanded disclosures regarding fair value measurements. ASU 2011-04 became effective for the Company's fiscal year 2012. The adoption of the measurement guidance of ASU 2011-04 did not have a material impact on the Condensed Consolidated Financial Statements. The new disclosures have been included with the Company's fair value disclosures in Note 3 of Notes to the Condensed Consolidated Financial Statements. In June 2011, the FASB issued ASU No. 2011-05, “Comprehensive Income (Topic 220) - Presentation of Comprehensive Income” (ASU 2011-05). ASU 2011-05 requires entities to present the total of comprehensive income, the components of net income, and the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements and eliminates the option to present the components of other comprehensive income as a part of the statement of equity. ASU 2011-05 became effective for the Company's fiscal year 2012. The Company presented separate Condensed Consolidated Statements of Comprehensive Income, which appear consecutive to the Condensed Consolidated Statements of Operations. The Company has determined that there have been no other recently adopted or issued accounting standards that had or will have a material impact on its Condensed Consolidated Financial Statements.

Basis of Presentation

UnitedHealth Group Incorporated (also referred to as “UnitedHealth Group” and the “Company”) is a diversified health and well-being company dedicated to helping people live healthier lives and making health care work better. We offer a broad spectrum of products and services through two distinct platforms: UnitedHealthcare, which provides health care coverage and benefits services; and Optum, which provides information and technology-enabled health services.

The Company has prepared the Condensed Consolidated Financial Statements according to U.S. Generally Accepted Accounting Principles (GAAP) and has included the accounts of UnitedHealth Group and its subsidiaries. The Company has eliminated intercompany balances and transactions. The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. In accordance with the rules and regulations of the U.S. Securities and Exchange Commission (SEC), the Company has omitted certain footnote disclosures that would substantially duplicate the disclosures contained in its annual audited Consolidated Financial Statements. Therefore, these Condensed Consolidated Financial Statements should be read together with the Consolidated Financial Statements and the Notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2011 as filed with the SEC (2011 10-K). The accompanying Condensed Consolidated Financial Statements include all normal recurring adjustments necessary to present the interim financial statements fairly.

Use of Estimates

These Condensed Consolidated Financial Statements include certain amounts based on the Company’s best estimates and judgments. The Company’s most significant estimates relate to medical costs payable and medical costs, premium rebates and risk-adjustment and risk-sharing provisions related to revenues, valuation and impairment analysis of goodwill and other intangible assets, estimates of other policy liabilities and other current receivables, valuations of investments, income taxes and contingent liabilities. These estimates require the application of complex assumptions and judgments, often because they involve matters that are inherently uncertain and will likely change in subsequent periods. The impact of any changes in estimates is included in earnings in the period in which the estimate is adjusted.

Accounting Policies

Following is an expanded portion of the Company's revenue policy related to premium rebates. All other accounting policies disclosed in Note 2 of Notes to the Consolidated Financial Statements in the 2011 10-K remain unchanged.

The Company's fully insured commercial premium revenues are generally subject to the minimum medical loss ratio requirements of the Patient Protection and Affordable Care Act and the associated reconciliation measure, the Health Care and Education Reconciliation Act of 2010 (Health Reform Legislation). Premium revenues are recognized based on the estimated premiums earned net of projected rebates because the Company is able to reasonably estimate the ultimate premiums of these contracts. Each period, the Company estimates premium rebates based on the expected financial performance of the applicable contracts within each defined aggregation set (e.g., by state, group size and licensed subsidiary). The most significant factors in estimating the financial performance are current and future premiums and medical claim experience, effective tax rates and expected changes in business mix. The estimated ultimate premium is revised each period to reflect current and projected experience.

Recently Adopted Accounting Standards

In May 2011, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2011-04, “Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRSs” (ASU 2011-04). This update provides guidance on how fair value measurement should be applied where existing GAAP already requires or permits fair value measurements. In addition, ASU 2011-04 requires expanded disclosures regarding fair value measurements. ASU 2011-04 became effective for the Company's fiscal year 2012. The adoption of the measurement guidance of ASU 2011-04 did not have a material impact on the Condensed Consolidated Financial Statements. The new disclosures have been included with the Company's fair value disclosures in Note 3 of Notes to the Condensed Consolidated Financial Statements.

In June 2011, the FASB issued ASU No. 2011-05, “Comprehensive Income (Topic 220) - Presentation of Comprehensive Income” (ASU 2011-05). ASU 2011-05 requires entities to present the total of comprehensive income, the components of net income, and the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements and eliminates the option to present the components of other comprehensive income as a part of the statement of equity. ASU 2011-05 became effective for the Company's fiscal year 2012. The Company presented separate Condensed Consolidated Statements of Comprehensive Income, which appear consecutive to the Condensed Consolidated Statements of Operations.

The Company has determined that there have been no other recently adopted or issued accounting standards that had or will have a material impact on its Condensed Consolidated Financial Statements.