2.2.0.25truefalse41603 - Disclosure - Schedule I (Condensed Statements of Cash Flows) (Details)truefalseIn Millionsfalse1falsefalseUSDfalsefalse1/1/2010 - 12/31/2010 USD ($) USD ($) / shares $Duration_1_1_2010_To_12_31_2010http://www.sec.gov/CIK0000731766duration2010-01-01T00:00:002010-12-31T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit13Standardhttp://www.xbrl.org/2003/instancepurexbrli0Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit14Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2falsefalseUSDfalsefalse1/1/2009 - 12/31/2009 USD ($) USD ($) / shares $Duration_1_1_2009_To_12_31_20092http://www.sec.gov/CIK0000731766duration2009-01-01T00:00:002009-12-31T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit13Standardhttp://www.xbrl.org/2003/instancepurexbrli0Unit14Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0USDUSD$3falsefalseUSDfalsefalse1/1/2008 - 12/31/2008 USD ($) USD ($) / shares $Duration_1_1_2008_To_12_31_20082http://www.sec.gov/CIK0000731766duration2008-01-01T00:00:002008-12-31T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit14Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit13Standardhttp://www.xbrl.org/2003/instancepurexbrli0Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2false0us-gaap_NetCashProvidedByUsedInOperatingActivitiesus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse62730000006273falsetruefalsefalsefalse2truefalsefalse56250000005625falsetruefalsefalsefalse3truefalsefalse42380000004238falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net cash from (used in) all of the entity's operating activities, including those of discontinued operations, of the reporting entity. Operating activities generally involve producing and delivering goods and providing services. Operating activity cash flows include transactions, adjustments, and changes in value that are not defined as investing or financing activities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 truefalse3false0us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquiredus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-2323000000-2323falsefalsefalsefalsefalse2truefalsefalse-486000000-486falsefalsefalsefalsefalse3truefalsefalse-4012000000-4012falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15, 17 falsefalse4false0us-gaap_NetCashProvidedByUsedInInvestingActivitiesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse-5339000000-5339falsefalsefalsefalsefalse2truefalsefalse-976000000-976falsefalsefalsefalsefalse3truefalsefalse-5072000000-5072falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net cash inflow (outflow) from investing activity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 truefalse5false0unh_ProceedsFromRepaymentsofCommercialPaperunhfalsedebitdurationThe net cash inflow (outflow) associated with commercial paper.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse930000000930falsefalsefalsefalsefalse2truefalsefalse-99000000-99falsefalsefalsefalsefalse3truefalsefalse-1346000000-1346falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net cash inflow (outflow) associated with commercial paper.No authoritative reference available.falsefalse6false0us-gaap_ProceedsFromIssuanceOfLongTermDebtus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse747000000747falsefalsefalsefalsefalse2truefalsefalse00falsefalsefalsefalsefalse3truefalsefalse29810000002981falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b falsefalse7false0us-gaap_RepaymentsOfLongTermDebtus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-1583000000-1583falsefalsefalsefalsefalse2truefalsefalse-1350000000-1350falsefalsefalsefalsefalse3truefalsefalse-500000000-500falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph b falsefalse8false0us-gaap_PaymentsForProceedsFromHedgeFinancingActivitiesus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse00falsefalsefalsefalsefalse2truefalsefalse513000000513falsefalsefalsefalsefalse3truefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net cash outflow (inflow) for a financial contract that meets the hedge criteria as either cash flow hedge, fair value hedge or hedge of net investment in foreign operations.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 14 -Subparagraph FN4 falsefalse9false0us-gaap_PaymentsForRepurchaseOfCommonStockus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-2517000000-2517falsefalsefalsefalsefalse2truefalsefalse-1801000000-1801falsefalsefalsefalsefalse3truefalsefalse-2684000000-2684falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cash outflow to reacquire common stock during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph a falsefalse10false0us-gaap_ProceedsFromIssuanceOfCommonStockus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse272000000272falsefalsefalsefalsefalse2truefalsefalse282000000282falsefalsefalsefalsefalse3truefalsefalse299000000299falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cash inflow from the additional capital contribution to the entity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph a falsefalse11false0us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivitiesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse2700000027falsefalsefalsefalsefalse2truefalsefalse3800000038falsefalsefalsefalsefalse3truefalsefalse6200000062falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryReductions in the entity's income taxes that arise when compensation cost (from non-qualified share-based compensation) recognized on the entity's tax return exceeds compensation cost from share-based compensation recognized in financial statements. This element represents the cash inflow reported in the enterprise's financing activities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph A240 -Subparagraph i Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 00-15 -Paragraph 3 falsefalse12false0us-gaap_PaymentsOfDividendsus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-449000000-449falsefalsefalsefalsefalse2truefalsefalse-36000000-36falsefalsefalsefalsefalse3truefalsefalse-37000000-37falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cash outflow from the entity's earnings to the shareholders.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph a falsefalse13false0us-gaap_ProceedsFromPaymentsForOtherFinancingActivitiesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse-7000000-7falsefalsefalsefalsefalse2truefalsefalse-48000000-48falsefalsefalsefalsefalse3truefalsefalse-143000000-143falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net cash inflow (outflow) from other financing activities. This element is used when there is not a more specific and appropriate element in the taxonomy.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18, 19, 20 falsefalse14false0us-gaap_NetCashProvidedByUsedInFinancingActivitiesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse-1611000000-1611falsefalsefalsefalsefalse2truefalsefalse-2275000000-2275falsefalsefalsefalsefalse3truefalsefalse-605000000-605falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net cash inflow (outflow) from financing activity for the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 truefalse15false0us-gaap_CashAndCashEquivalentsPeriodIncreaseDecreaseus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse-677000000-677falsefalsefalsefalsefalse2truefalsefalse23740000002374falsefalsefalsefalsefalse3truefalsefalse-1439000000-1439falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net change between the beginning and ending balance of cash and cash equivalents.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 truefalse16false0us-gaap_CashAndCashEquivalentsAtCarryingValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse98000000009800falsefalsefalsefalsefalse2truefalsefalse74260000007426falsefalsefalsefalsefalse3truefalsefalse88650000008865falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncludes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 falsefalse17false0us-gaap_CashAndCashEquivalentsAtCarryingValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse91230000009123falsefalsefalsefalsefalse2truefalsefalse98000000009800falsefalsefalsefalsefalse3truefalsefalse74260000007426falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncludes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 falsefalse18false0us-gaap_InterestPaidus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse509000000509falsefalsefalsefalsefalse2truefalsefalse527000000527falsefalsefalsefalsefalse3truefalsefalse621000000621falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of cash paid during the current period for interest owed on money borrowed; includes amount of interest capitalizedReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 29 falsefalse19false0us-gaap_IncomeTaxesPaidNetus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse27250000002725falsefalsefalsefalsefalse2truefalsefalse20480000002048falsefalsefalsefalsefalse3truefalsefalse18820000001882falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 29 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 27 -Subparagraph f falsefalse20false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.unitedhealthgroup.com/taxonomy/role/disclosurescheduleicondensedstatementsofcashflowsdetails1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalseUSDtruefalse{dei_LegalEntityAxis} : Parent Company [Member] 1/1/2010 - 12/31/2010 USD ($) $Duration_1_1_2010_To_12_31_20102http://www.sec.gov/CIK0000731766duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseParent Company [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ParentCompanyMemberdei_LegalEntityAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit14Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$5falsefalseUSDtruefalse{dei_LegalEntityAxis} : Parent Company [Member] 1/1/2009 - 12/31/2009 USD ($) $Duration_1_1_2009_To_12_31_2009http://www.sec.gov/CIK0000731766duration2009-01-01T00:00:002009-12-31T00:00:00falsefalseParent Company [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ParentCompanyMemberdei_LegalEntityAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit14Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$6falsefalseUSDtruefalse{dei_LegalEntityAxis} : Parent Company [Member] 1/1/2008 - 12/31/2008 USD ($) $Duration_1_1_2008_To_12_31_2008http://www.sec.gov/CIK0000731766duration2008-01-01T00:00:002008-12-31T00:00:00falsefalseParent Company [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ParentCompanyMemberdei_LegalEntityAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse21false0us-gaap_NetCashProvidedByUsedInOperatingActivitiesus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse37310000003731falsefalsefalsefalsefalse2truefalsefalse50650000005065falsefalsefalsefalsefalse3truefalsefalse39620000003962falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net cash from (used in) all of the entity's operating activities, including those of discontinued operations, of the reporting entity. Operating activities generally involve producing and delivering goods and providing services. Operating activity cash flows include transactions, adjustments, and changes in value that are not defined as investing or financing activities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 truefalse22false0unh_CapitalContributionsToSubsidiariesunhfalsecreditdurationCapital contributions to subsidiariesfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse-104000000-104falsefalsefalsefalsefalse2truefalsefalse-90000000-90falsefalsefalsefalsefalse3truefalsefalse-7000000-7falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCapital contributions to subsidiariesNo authoritative reference available.falsefalse23false0us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquiredus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-2470000000-2470falsefalsefalsefalsefalse2truefalsefalse-1045000000-1045falsefalsefalsefalsefalse3truefalsefalse-4419000000-4419falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15, 17 falsefalse24false0us-gaap_ProceedsFromSaleOfOtherInvestmentsus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse00falsefalsefalsefalsefalse2truefalsefalse00falsefalsefalsefalsefalse3truefalsefalse185000000185falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cash inflow associated with the sale of other investments not otherwise defined in the taxonomy.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 31 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 18 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 falsefalse25false0us-gaap_NetCashProvidedByUsedInInvestingActivitiesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse-2574000000-2574falsefalsefalsefalsefalse2truefalsefalse-1135000000-1135falsefalsefalsefalsefalse3truefalsefalse-4241000000-4241falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net cash inflow (outflow) from investing activity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 truefalse26false0unh_ProceedsFromRepaymentsofCommercialPaperunhfalsedebitdurationThe net cash inflow (outflow) associated with commercial paper.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse930000000930falsefalsefalsefalsefalse2truefalsefalse-99000000-99falsefalsefalsefalsefalse3truefalsefalse-1346000000-1346falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net cash inflow (outflow) associated with commercial paper.No authoritative reference available.falsefalse27false0us-gaap_ProceedsFromIssuanceOfLongTermDebtus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse747000000747falsefalsefalsefalsefalse2truefalsefalse00falsefalsefalsefalsefalse3truefalsefalse29810000002981falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b falsefalse28false0us-gaap_RepaymentsOfLongTermDebtus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-1583000000-1583falsefalsefalsefalsefalse2truefalsefalse-1350000000-1350falsefalsefalsefalsefalse3truefalsefalse-500000000-500falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph b falsefalse29false0us-gaap_PaymentsForProceedsFromHedgeFinancingActivitiesus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse00falsefalsefalsefalsefalse2truefalsefalse513000000513falsefalsefalsefalsefalse3truefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net cash outflow (inflow) for a financial contract that meets the hedge criteria as either cash flow hedge, fair value hedge or hedge of net investment in foreign operations.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 14 -Subparagraph FN4 falsefalse30false0unh_ProceedsFromIssuanceOfNoteToSubsidiaryunhfalsedebitdurationProceeds from issuance of note to subsidiaryfalsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse3000000030falsefalsefalsefalsefalse2truefalsefalse00falsefalsefalsefalsefalse3truefalsefalse100000000100falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryProceeds from issuance of note to subsidiaryNo authoritative reference available.falsefalse31false0us-gaap_PaymentsForRepurchaseOfCommonStockus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-2517000000-2517falsefalsefalsefalsefalse2truefalsefalse-1801000000-1801falsefalsefalsefalsefalse3truefalsefalse-2684000000-2684falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cash outflow to reacquire common stock during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph a falsefalse32false0us-gaap_ProceedsFromIssuanceOfCommonStockus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse272000000272falsefalsefalsefalsefalse2truefalsefalse282000000282falsefalsefalsefalsefalse3truefalsefalse299000000299falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cash inflow from the additional capital contribution to the entity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph a falsefalse33false0us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivitiesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse2700000027falsefalsefalsefalsefalse2truefalsefalse3800000038falsefalsefalsefalsefalse3truefalsefalse6200000062falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryReductions in the entity's income taxes that arise when compensation cost (from non-qualified share-based compensation) recognized on the entity's tax return exceeds compensation cost from share-based compensation recognized in financial statements. This element represents the cash inflow reported in the enterprise's financing activities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph A240 -Subparagraph i Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 00-15 -Paragraph 3 falsefalse34false0us-gaap_PaymentsOfDividendsus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-449000000-449falsefalsefalsefalsefalse2truefalsefalse-36000000-36falsefalsefalsefalsefalse3truefalsefalse-37000000-37falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cash outflow from the entity's earnings to the shareholders.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph a falsefalse35false0us-gaap_ProceedsFromPaymentsForOtherFinancingActivitiesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse-7000000-7falsefalsefalsefalsefalse2truefalsefalse-48000000-48falsefalsefalsefalsefalse3truefalsefalse-143000000-143falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net cash inflow (outflow) from other financing activities. This element is used when there is not a more specific and appropriate element in the taxonomy.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18, 19, 20 falsefalse36false0us-gaap_NetCashProvidedByUsedInFinancingActivitiesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse-2550000000-2550falsefalsefalsefalsefalse2truefalsefalse-2501000000-2501falsefalsefalsefalsefalse3truefalsefalse-1268000000-1268falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net cash inflow (outflow) from financing activity for the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 truefalse37false0us-gaap_CashAndCashEquivalentsPeriodIncreaseDecreaseus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse-1393000000-1393falsefalsefalsefalsefalse2truefalsefalse14290000001429falsefalsefalsefalsefalse3truefalsefalse-1547000000-1547falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net change between the beginning and ending balance of cash and cash equivalents.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 truefalse38false0us-gaap_CashAndCashEquivalentsAtCarryingValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsetruefalsefalseperiodstartlabel1truefalsefalse23090000002309falsefalsefalsefalsefalse2truefalsefalse880000000880falsefalsefalsefalsefalse3truefalsefalse24270000002427falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncludes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 falsefalse39false0us-gaap_CashAndCashEquivalentsAtCarryingValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsetruefalseperiodendlabel1truefalsefalse916000000916falsefalsefalsefalsefalse2truefalsefalse23090000002309falsefalsefalsefalsefalse3truefalsefalse880000000880falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncludes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 falsefalse40false0us-gaap_InterestPaidus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse459000000459falsefalsefalsefalsefalse2truefalsefalse485000000485falsefalsefalsefalsefalse3truefalsefalse547000000547falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of cash paid during the current period for interest owed on money borrowed; includes amount of interest capitalizedReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 29 falsefalse41false0us-gaap_IncomeTaxesPaidNetus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse27250000002725falsetruefalsefalsefalse2truefalsefalse20480000002048falsetruefalsefalsefalse3truefalsefalse18820000001882falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 29 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 27 -Subparagraph f falsefalse340Schedule I (Condensed Statements of Cash Flows) (Details) (USD $)MillionsUnKnownUnKnownUnKnownfalsetrue