2.2.0.7 true Fair Value (Reconciliation of Assets Measured at Fair Value on a Recurring Basis Using Level 3 Inputs) (Details) (USD $) 40303 - Disclosure - Fair Value (Reconciliation of Assets Measured at Fair Value on a Recurring Basis Using Level 3 Inputs) (Details) true false In Millions false false 1 USD false false Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Unit14 Standard http://www.xbrl.org/2003/instance pure xbrli 0 Unit1 Standard http://www.xbrl.org/2003/instance shares xbrli 0 Unit13 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 $ false 2 USD false false Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Unit14 Standard http://www.xbrl.org/2003/instance pure xbrli 0 Unit1 Standard http://www.xbrl.org/2003/instance shares xbrli 0 Unit13 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 $ false 3 USD false false Unit13 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Unit14 Standard http://www.xbrl.org/2003/instance pure xbrli 0 Unit1 Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 4 USD false false Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Unit14 Standard http://www.xbrl.org/2003/instance pure xbrli 0 Unit1 Standard http://www.xbrl.org/2003/instance shares xbrli 0 Unit13 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 $ 2 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue us-gaap true debit instant No definition available. false false false false false false false false true false false periodstartlabel false 1 true true false false 293000000 293 false false false 2 true true false false 369000000 369 false false false 3 true true false false 432000000 432 false false false 4 true true false false 366000000 366 false false false xbrli:monetaryItemType monetary This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c false 3 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlements us-gaap true debit duration No definition available. false false false false false false false false false false false false 1 false true false false 54000000 54 false false false 2 false true false false 1000000 1 false false false 3 false true false false -102000000 -102 false false false 4 false true false false 4000000 4 false false false xbrli:monetaryItemType monetary This element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) false 4 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncome us-gaap true debit duration No definition available. false false false false false false false false false false false false 1 false true false false 3000000 3 false false false 2 false true false false 7000000 7 false false false 3 false true false false 9000000 9 false false false 4 false true false false 12000000 12 false false false xbrli:monetaryItemType monetary This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) false 5 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false -1000000 -1 false false false 2 false true false false -14000000 -14 false false false 3 false true false false 10000000 10 false false false 4 false true false false -19000000 -19 false false false xbrli:monetaryItemType monetary This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) false 6 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue us-gaap true debit instant No definition available. false false false false false false false false false true false periodendlabel false 1 false true false false 349000000 349 false false false 2 false true false false 363000000 363 false false false 3 false true false false 349000000 349 false false false 4 false true false false 363000000 363 false false false xbrli:monetaryItemType monetary This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c false 7 0 na true na na No definition available. false true false false false false false false false false false http://www.unitedhealthgroup.com/taxonomy/role/disclosurereconciliationofassetsmeasuredatfairvalueonarecurringbasisusinglevel3inputs false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false false 5 USD true false false false Debt Securities us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_DebtSecuritiesMember us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis explicitMember Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 6 USD true false false false Debt Securities us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_DebtSecuritiesMember us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis explicitMember Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 7 USD true false false false Debt Securities us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_DebtSecuritiesMember us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis explicitMember Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 8 USD true false false false Debt Securities us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_DebtSecuritiesMember us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis explicitMember Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 8 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue us-gaap true debit instant No definition available. false false false false false false false false true false false periodstartlabel false 1 false true false false 107000000 107 false false false 2 false true false false 60000000 60 false false false 3 false true false false 120000000 120 false false false 4 false true false false 62000000 62 false false false xbrli:monetaryItemType monetary This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c false 9 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlements us-gaap true debit duration No definition available. false false false false false false false false false false false false 1 false true false false 39000000 39 false false false 2 false true false false -3000000 -3 false false false 3 false true false false 25000000 25 false false false 4 false true false false -5000000 -5 false false false xbrli:monetaryItemType monetary This element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) false 10 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncome us-gaap true debit duration No definition available. false false false false false false false false false false false false 1 false true false false 0 0 false false false 2 false true false false 1000000 1 false false false 3 false true false false 0 0 false false false 4 false true false false 1000000 1 false false false xbrli:monetaryItemType monetary This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) false 11 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 0 0 false false false 2 false true false false -4000000 -4 false false false 3 false true false false 1000000 1 false false false 4 false true false false -4000000 -4 false false false xbrli:monetaryItemType monetary This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) false 12 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue us-gaap true debit instant No definition available. false false false false false false false false false true false periodendlabel false 1 false true false false 146000000 146 false false false 2 false true false false 54000000 54 false false false 3 false true false false 146000000 146 false false false 4 false true false false 54000000 54 false false false xbrli:monetaryItemType monetary This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c false 13 0 na true na na No definition available. false true false false false false false false false false false http://www.unitedhealthgroup.com/taxonomy/role/disclosurereconciliationofassetsmeasuredatfairvalueonarecurringbasisusinglevel3inputs false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false false 9 USD true false false false Equity Securities us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_EquitySecuritiesMember us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis explicitMember Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 10 USD true false false false Equity Securities us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_EquitySecuritiesMember us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis explicitMember Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 11 USD true false false false Equity Securities us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_EquitySecuritiesMember us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis explicitMember Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 12 USD true false false false Equity Securities us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_EquitySecuritiesMember us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetTypeAxis explicitMember Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 14 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue us-gaap true debit instant No definition available. false false false false false false false false true false false periodstartlabel false 1 false true false false 186000000 186 false false false 2 false true false false 309000000 309 false false false 3 false true false false 312000000 312 false false false 4 false true false false 304000000 304 false false false xbrli:monetaryItemType monetary This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c false 15 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlements us-gaap true debit duration No definition available. false false false false false false false false false false false false 1 false true false false 15000000 15 false false false 2 false true false false 4000000 4 false false false 3 false true false false -127000000 -127 false false false 4 false true false false 9000000 9 false false false xbrli:monetaryItemType monetary This element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(2) false 16 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncome us-gaap true debit duration No definition available. false false false false false false false false false false false false 1 false true false false 3000000 3 false false false 2 false true false false 6000000 6 false false false 3 false true false false 9000000 9 false false false 4 false true false false 11000000 11 false false false xbrli:monetaryItemType monetary This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) false 17 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false -1000000 -1 false false false 2 false true false false -10000000 -10 false false false 3 false true false false 9000000 9 false false false 4 false true false false -15000000 -15 false false false xbrli:monetaryItemType monetary This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c(1) false 18 2 us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue us-gaap true debit instant No definition available. false false false false false false false false false true false periodendlabel false 1 true true false false 203000000 203 false false false 2 true true false false 309000000 309 false false false 3 true true false false 203000000 203 false false false 4 true true false false 309000000 309 false false false xbrli:monetaryItemType monetary This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c false 4 17 false Millions UnKnown UnKnown false true