2.2.0.25falsefalse41302 - Disclosure - Commitments and Contingencies (Future Minimum Annual Lease Payments, Net of Sublease Income, Under all Noncancelable Operating Leases) (Details)truefalseIn Millionsfalse1falsefalseUSDfalsefalse12/31/2010
USD ($)
USD ($) / shares
$As_Of_12_31_20103http://www.sec.gov/CIK0000731766instant2010-12-31T00:00:000001-01-01T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit14Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit13Standardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$2true0unh_CommitmentsAndContingenciesAbstractunhfalsenadurationCommitments And Contingenciesfalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringCommitments And Contingenciesfalsefalse3false0us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse259000000259falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within one year of the balance sheet date relating to leases defined as operating.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 122
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 16
-Subparagraph b(i)
falsefalse4false0us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYearsus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse240000000240falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the second year of the balance sheet date relating to leases defined as operating.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 122
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 16
-Subparagraph b(i)
falsefalse5false0us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYearsus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse191000000191falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the third year of the balance sheet date relating to leases defined as operating.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 122
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 16
-Subparagraph b(i)
falsefalse6false0us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYearsus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse156000000156falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the fourth year of the balance sheet date relating to leases defined as operating.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 122
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 16
-Subparagraph b(i)
falsefalse7false0us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYearsus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse129000000129falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the fifth year of the balance sheet date relating to leases defined as operating.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 122
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 16
-Subparagraph b(i)
falsefalse8false0us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafterus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse579000000579falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due after the fifth year from the balance sheet date on leases defined as operating.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 122
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 16
-Subparagraph b(i)
falsefalse17Commitments and Contingencies (Future Minimum Annual Lease Payments, Net of Sublease Income, Under all Noncancelable Operating Leases) (Details) (USD $)MillionsUnKnownUnKnownUnKnownfalsetrue