2.2.0.25truefalse41001 - Disclosure - Shareholders' Equity (Narrative) (Details)truefalseShare data in Millions, except Per Share datafalse1falsefalseUSDfalsefalse1/1/2010 - 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$4falsefalsefalsefalse2/28/2010
As_Of_2_28_2010http://www.sec.gov/CIK0000731766instant2010-02-28T00:00:000001-01-01T00:00:00Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli02false0us-gaap_CashDividendsPaidToParentCompanyByConsolidatedSubsidiariesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse43000000004300000000falsetruefalsefalsefalse2truefalsefalse54000000005400000000falsetruefalsefalsefalse3truefalsefalse18000000001800000000falsetruefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents disclosure of the aggregate cash dividends paid to the entity by consolidated subsidiaries.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph b
-Article 12
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 06
-Article 9
falsefalse3false0us-gaap_StatutoryAccountingPracticesStatutoryAmountAvailableForDividendPaymentsus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse32000000003200000000falsefalsefalsefalsefalse2truefalsefalse31000000003100000000falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAmount available as of the balance sheet date for dividend payments after computation of statutory restrictions on capital surplus.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 60
-Paragraph 60
-Subparagraph h
falsefalse4false0unh_CashDividendsPaidToParentCompanyByConsolidatedSubsidiariesExtraordinaryDividendsunhfalsecreditdurationCash dividends paid to parent Company by consolidated subsidiaries, extraordinary dividends.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse686000000686000000falsefalsefalsefalsefalse2truefalsefalse25000000002500000000falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCash dividends paid to parent Company by consolidated subsidiaries, extraordinary dividends.No authoritative reference available.falsefalse5false0unh_AdditionalSharesAuthorizedForRepurchaseunhfalsenainstantAdditional shares authorized for repurchasefalsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse4800000048falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4truefalsefalse120000000120falsefalsefalsefalsefalseSharesxbrli:sharesItemTypesharesAdditional shares authorized for repurchaseNo authoritative reference available.falsefalse6false0unh_CashAndInvestmentHeldByNonRegulatedEntitiesunhfalsedebitdurationCash and investment held by non-regulated entities.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse974000000974000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCash and investment held by non-regulated entities.No authoritative reference available.falsefalse7false0us-gaap_InvestmentsAndCashus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse2590000000025900000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetarySum of investments and unrestricted cash as of the balance sheet dateNo authoritative reference available.falsefalse8false0us-gaap_StatutoryAccountingPracticesStatutoryCapitalAndSurplusBalanceus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse1100000000011000000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of statutory capital and surplus (stockholders' equity) as of the balance sheet date using prescribed or permitted statutory accounting practices (rather than GAAP, if different) of the state or country.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 60
-Paragraph 60
-Subparagraph h
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 94-5
-Paragraph 8, 9
Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 24
-Subparagraph c
-Article 7
falsefalse9false0us-gaap_PaymentsForRepurchaseOfCommonStockus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse25170000002517000000falsefalsefalsefalsefalse2truefalsefalse18010000001801000000falsefalsefalsefalsefalse3truefalsefalse26840000002684000000falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli: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_StockRepurchasedDuringPeriodSharesus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse7600000076falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseSharesxbrli:sharesItemTypesharesNumber of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30
-Article 5
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 12
-Paragraph 10
Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3
Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 43
-Chapter 1
-Section B
-Paragraph 11A
falsefalse11false0us-gaap_TreasuryStockAcquiredAverageCostPerShareus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse3333falsetruefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseEPSus-types:perShareItemTypedecimalTotal cost of shares repurchased divided by the total number of shares repurchased.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 43
-Chapter 1
-Section B
-Paragraph 7
-Subparagraph b
falsetrue12false0us-gaap_StockRepurchasedDuringPeriodValueus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse25170000002517000000falsefalsefalsefalsefalse2truefalsefalse18010000001801000000falsefalsefalsefalsefalse3truefalsefalse26840000002684000000falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30, 31
-Article 5
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 12
-Paragraph 10
Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3
Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 43
-Chapter 1
-Section B
-Paragraph 11A
falsefalse13false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.unitedhealthgroup.com/taxonomy/role/disclosureshareholdersequitynarrativedetails1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalse5falsefalseUSDtruefalse{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/iso4217USDiso42170USDUSD$6falsefalseUSDtruefalse{dei_LegalEntityAxis} : Parent Company [Member]
1/1/2009 - 12/31/2009
USD ($)
$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/iso4217USDiso42170USDUSD$7falsefalseUSDtruefalse{dei_LegalEntityAxis} : Parent Company [Member]
1/1/2008 - 12/31/2008
USD ($)
$Duration_1_1_2008_To_12_31_2008http://www.sec.gov/CIK0000731766duration2008-01-01T00:00:002008-12-31T00:00:00falsefalseParent Company [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ParentCompanyMemberdei_LegalEntityAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalse14false0us-gaap_CashDividendsPaidToParentCompanyByConsolidatedSubsidiariesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse32000000003200000000falsefalsefalsefalsefalse2truefalsefalse42000000004200000000falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents disclosure of the aggregate cash dividends paid to the entity by consolidated subsidiaries.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph b
-Article 12
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 06
-Article 9
falsefalse15false0us-gaap_PaymentsForRepurchaseOfCommonStockus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse25170000002517000000falsetruefalsefalsefalse2truefalsefalse18010000001801000000falsetruefalsefalsefalse3truefalsefalse26840000002684000000falsetruefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli: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
falsefalse414Shareholders' Equity (Narrative) (Details) (USD $)NoRoundingMillionsNoRoundingUnKnownfalsetrue
