2.2.0.7 true Medicare Part D Pharmacy Benefits Contract (Condensed Consolidated Balance Sheets Amounts of Medicare Part D Program) (Details) (USD $) 40401 - Disclosure - Medicare Part D Pharmacy Benefits Contract (Condensed Consolidated Balance Sheets Amounts of Medicare Part D Program) (Details) true false In Millions false false 1 USD false false Unit1 Standard 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 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 Unit13 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Unit1 Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ 2 2 us-gaap_OtherReceivables us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 true true false false 1708000000 1708 false false false 2 true true false false 1838000000 1838 false false false xbrli:monetaryItemType monetary Carrying amounts due as of the balance sheet date from parties or arising from transactions not otherwise specified in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 3 2 us-gaap_OtherPolicyholderFunds us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 4074000000 4074 false false false 2 false true false false 3137000000 3137 false false false xbrli:monetaryItemType monetary Liability as of the balance sheet date to the policyholders for funds held that are returnable under the terms of insurance contracts that were not separately reported. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 14 -Article 7 false 4 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/disclosurecondensedconsolidatedbalancesheetsamountsofmedicarepartdprogram false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false false 3 USD true false false false CMS Subsidies us-gaap_SupplementaryInsuranceInformationSegmentNameAxis xbrldi http://xbrl.org/2006/xbrldi unh_CMSSubsidiesMember us-gaap_SupplementaryInsuranceInformationSegmentNameAxis explicitMember Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 4 USD true false false false CMS Subsidies us-gaap_SupplementaryInsuranceInformationSegmentNameAxis xbrldi http://xbrl.org/2006/xbrldi unh_CMSSubsidiesMember us-gaap_SupplementaryInsuranceInformationSegmentNameAxis explicitMember Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 5 2 us-gaap_OtherReceivables us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 0 0 [1] false false false 2 false true false false 271000000 271 [1] false false false xbrli:monetaryItemType monetary Carrying amounts due as of the balance sheet date from parties or arising from transactions not otherwise specified in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 6 2 us-gaap_OtherPolicyholderFunds us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 544000000 544 [1] false false false 2 false true false false 0 0 [1] false false false xbrli:monetaryItemType monetary Liability as of the balance sheet date to the policyholders for funds held that are returnable under the terms of insurance contracts that were not separately reported. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 14 -Article 7 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/disclosurecondensedconsolidatedbalancesheetsamountsofmedicarepartdprogram false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false false 5 USD true false false false Risk-share us-gaap_SupplementaryInsuranceInformationSegmentNameAxis xbrldi http://xbrl.org/2006/xbrldi unh_RiskShareMember us-gaap_SupplementaryInsuranceInformationSegmentNameAxis explicitMember Unit12 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 6 USD true false false false Risk-share us-gaap_SupplementaryInsuranceInformationSegmentNameAxis xbrldi http://xbrl.org/2006/xbrldi unh_RiskShareMember us-gaap_SupplementaryInsuranceInformationSegmentNameAxis 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_OtherReceivables us-gaap true debit instant 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 0 0 false false false xbrli:monetaryItemType monetary Carrying amounts due as of the balance sheet date from parties or arising from transactions not otherwise specified in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 9 2 us-gaap_OtherPolicyholderFunds us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 true true false false 353000000 353 false false false 2 true true false false 268000000 268 false false false xbrli:monetaryItemType monetary Liability as of the balance sheet date to the policyholders for funds held that are returnable under the terms of insurance contracts that were not separately reported. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 14 -Article 7 false 1 Includes the Catastrophic Reinsurance Subsidy and the Low-Income Member Cost Sharing Subsidy. 2 8 false Millions UnKnown UnKnown false true