Basis of Presentation (Notes)	9 Months Ended
Sep. 30, 2017
Basis of Presentation and Significant Accounting Policies [Text Block]	Basis of Presentation and Significant Accounting Policies UnitedHealth Group Incorporated (individually and together with its subsidiaries, “UnitedHealth Group” and “the Company”) is a diversified health and well-being company dedicated to helping people live healthier lives and helping make the health system work better for everyone. Through its diversified family of businesses, the Company leverages core competencies in advanced, enabling technology; health care data, information and intelligence; and clinical care management and coordination to help meet the demands of the health system. These core competencies are deployed within the Company’s two distinct, but strategically aligned, business platforms: health benefits operating under UnitedHealthcare and health services operating under Optum. 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 year-end condensed consolidated balance sheet 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 Part II, Item 8, “Financial Statements” in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 as filed with the SEC (2016 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 estimates and judgments for medical costs payable and revenues, valuation and impairment analysis of goodwill and other intangible assets and valuations of certain investments. Certain of 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 change in estimates is included in earnings in the period in which the estimate is adjusted. Revenues The Company’s revenues include premium, product, and service revenues. Service revenues include net patient service revenues that are recorded based upon established billing rates, less allowances for contractual adjustments, and are recognized as services are provided. For more information about the Company’s revenues, see Notes 2 and 13 of Notes to the Consolidated Financial Statements in Part II, Item 8, “Financial Statements” in the 2016 10-K. See Note 9 for disaggregation of revenue by segment and type. As of September 30, 2017, accounts receivables related to products and services were $3.5 billion. For the three and nine months ended September 30, 2017, the Company had no material bad-debt expense and there were no material contract assets, contract liabilities or deferred contract costs recorded on the Condensed Consolidated Balance Sheet as of September 30, 2017. For the three and nine months ended September 30, 2017, revenue recognized from performance obligations related to prior periods (for example, due to changes in transaction price), was not material. Revenue expected to be recognized in any future year related to remaining performance obligations, excluding revenue pertaining to contracts that have an original expected duration of one year or less, contracts where revenue is recognized as invoiced and contracts with variable consideration related to undelivered performance obligations, is not material. Health Insurance Industry Tax The Patient Protection and Affordable Care Act (ACA) included an annual, nondeductible insurance industry tax (Health Insurance Industry Tax) to be levied proportionally across the insurance industry for risk-based health insurance products. A provision in the 2016 Federal Budget imposed a one year moratorium for 2017 on the collection of the Health Insurance Industry Tax. The Company has experienced a lower effective income tax rate in 2017 as compared to 2016 primarily due to the moratorium. The remainder of the accounting policies disclosed in Note 2 of Notes to the Consolidated Financial Statements in Part II, Item 8, “Financial Statements” in the 2016 10-K remain unchanged. Recently Issued Accounting Standards In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) No. 2016-02, “Leases (Topic 842)” (ASU 2016-02). Under ASU 2016-02, an entity will be required to recognize assets and liabilities for the rights and obligations created by leases on the entity’s balance sheet for both finance and operating leases. For leases with a term of 12 months or less, an entity can elect to not recognize lease assets and lease liabilities and expense the lease over a straight-line basis for the term of the lease. ASU 2016-02 will require new disclosures that depict the amount, timing and uncertainty of cash flows pertaining to an entity’s leases. Companies are required to adopt the new standard using a modified retrospective approach for annual and interim periods beginning after December 15, 2018. Early adoption of ASU 2016-02 is permitted. When adopted, the Company does not expect ASU 2016-02 to have a material impact on its results of operations, equity or cash flows. The impact of ASU 2016-02 on the Company’s consolidated financial position will be based on leases outstanding at the time of adoption. In January 2016, the FASB issued ASU 2016-01, “Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities” (ASU 2016-01). The new guidance changes the current accounting related to (i) the classification and measurement of certain equity investments, (ii) the presentation of changes in the fair value of financial liabilities measured under the fair value option that are due to instrument-specific credit risk, and (iii) certain disclosures associated with the fair value of financial instruments. Most notably, ASU 2016-01 requires that equity investments, with certain exemptions, be measured at fair value with changes in fair value recognized in net income as opposed to other comprehensive income. The new guidance is effective for annual and interim reporting periods beginning after December 15, 2017. As of September 30, 2017, based on equity securities held, the Company does not expect ASU 2016-01 to have a material impact on its consolidated financial position, results of operations, equity or cash flows. The Company will continue to evaluate any changes in its mix of investments or market conditions and the related impact of ASU 2016-01. Recently Adopted Accounting Standards In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” as modified by subsequently issued ASUs 2015-14, 2016-08, 2016-10, 2016-12 and 2016-20 (collectively ASU 2014-09). ASU 2014-09 superseded existing revenue recognition standards with a single model unless those contracts are within the scope of other standards (e.g., an insurance entity’s insurance contracts). The revenue recognition principle in ASU 2014-09 is that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company early adopted the new standard effective January 1, 2017, as allowed, using the modified retrospective approach. A significant majority of the Company’s revenues are not subject to the new guidance. The adoption of ASU 2014-09 did not have a material impact on the Company’s consolidated financial position, results of operations, equity or cash flows as of the adoption date or for the nine months ended September 30, 2017. The Company has included the disclosures required by ASU 2014-09 above. 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 and Significant Accounting Policies

UnitedHealth Group Incorporated (individually and together with its subsidiaries, “UnitedHealth Group” and “the Company”) is a diversified health and well-being company dedicated to helping people live healthier lives and helping make the health system work better for everyone. Through its diversified family of businesses, the Company leverages core competencies in advanced, enabling technology; health care data, information and intelligence; and clinical care management and coordination to help meet the demands of the health system. These core competencies are deployed within the Company’s two distinct, but strategically aligned, business platforms: health benefits operating under UnitedHealthcare and health services operating under Optum.

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 year-end condensed consolidated balance sheet 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 Part II, Item 8, “Financial Statements” in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 as filed with the SEC (2016 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 estimates and judgments for medical costs payable and revenues, valuation and impairment analysis of goodwill and other intangible assets and valuations of certain investments. Certain of 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 change in estimates is included in earnings in the period in which the estimate is adjusted.

Revenues

The Company’s revenues include premium, product, and service revenues. Service revenues include net patient service revenues that are recorded based upon established billing rates, less allowances for contractual adjustments, and are recognized as services are provided. For more information about the Company’s revenues, see Notes 2 and 13 of Notes to the Consolidated Financial Statements in Part II, Item 8, “Financial Statements” in the 2016 10-K. See Note 9 for disaggregation of revenue by segment and type.

As of September 30, 2017, accounts receivables related to products and services were $3.5 billion. For the three and nine months ended September 30, 2017, the Company had no material bad-debt expense and there were no material contract assets, contract liabilities or deferred contract costs recorded on the Condensed Consolidated Balance Sheet as of September 30, 2017.

For the three and nine months ended September 30, 2017, revenue recognized from performance obligations related to prior periods (for example, due to changes in transaction price), was not material.

Revenue expected to be recognized in any future year related to remaining performance obligations, excluding revenue pertaining to contracts that have an original expected duration of one year or less, contracts where revenue is recognized as invoiced and contracts with variable consideration related to undelivered performance obligations, is not material.

Health Insurance Industry Tax

The Patient Protection and Affordable Care Act (ACA) included an annual, nondeductible insurance industry tax (Health Insurance Industry Tax) to be levied proportionally across the insurance industry for risk-based health insurance products. A provision in the 2016 Federal Budget imposed a one year moratorium for 2017 on the collection of the Health Insurance Industry Tax. The Company has experienced a lower effective income tax rate in 2017 as compared to 2016 primarily due to the moratorium.

The remainder of the accounting policies disclosed in Note 2 of Notes to the Consolidated Financial Statements in Part II, Item 8, “Financial Statements” in the 2016 10-K remain unchanged.

Recently Issued Accounting Standards

In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) No. 2016-02, “Leases (Topic 842)” (ASU 2016-02). Under ASU 2016-02, an entity will be required to recognize assets and liabilities for the rights and obligations created by leases on the entity’s balance sheet for both finance and operating leases. For leases with a term of 12 months or less, an entity can elect to not recognize lease assets and lease liabilities and expense the lease over a straight-line basis for the term of the lease. ASU 2016-02 will require new disclosures that depict the amount, timing and uncertainty of cash flows pertaining to an entity’s leases. Companies are required to adopt the new standard using a modified retrospective approach for annual and interim periods beginning after December 15, 2018. Early adoption of ASU 2016-02 is permitted. When adopted, the Company does not expect ASU 2016-02 to have a material impact on its results of operations, equity or cash flows. The impact of ASU 2016-02 on the Company’s consolidated financial position will be based on leases outstanding at the time of adoption.

In January 2016, the FASB issued ASU 2016-01, “Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities” (ASU 2016-01). The new guidance changes the current accounting related to (i) the classification and measurement of certain equity investments, (ii) the presentation of changes in the fair value of financial liabilities measured under the fair value option that are due to instrument-specific credit risk, and (iii) certain disclosures associated with the fair value of financial instruments. Most notably, ASU 2016-01 requires that equity investments, with certain exemptions, be measured at fair value with changes in fair value recognized in net income as opposed to other comprehensive income. The new guidance is effective for annual and interim reporting periods beginning after December 15, 2017. As of September 30, 2017, based on equity securities held, the Company does not expect ASU 2016-01 to have a material impact on its consolidated financial position, results of operations, equity or cash flows. The Company will continue to evaluate any changes in its mix of investments or market conditions and the related impact of ASU 2016-01.

Recently Adopted Accounting Standards

In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” as modified by subsequently issued ASUs 2015-14, 2016-08, 2016-10, 2016-12 and 2016-20 (collectively ASU 2014-09). ASU 2014-09 superseded existing revenue recognition standards with a single model unless those contracts are within the scope of other standards (e.g., an insurance entity’s insurance contracts). The revenue recognition principle in ASU 2014-09 is that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company early adopted the new standard effective January 1, 2017, as allowed, using the modified retrospective approach. A significant majority of the Company’s revenues are not subject to the new guidance. The adoption of ASU 2014-09 did not have a material impact on the Company’s consolidated financial position, results of operations, equity or cash flows as of the adoption date or for the nine months ended September 30, 2017. The Company has included the disclosures required by ASU 2014-09 above.

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.