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USD ($)
USD ($) / shares
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USD ($)
USD ($) / shares
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 11
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43, 289
falsefalse5false0us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsReturnsAndAllowancesus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse233000000233falsefalsefalsefalsefalse2truefalsefalse201000000201falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe tax effect as of the balance sheet date of the amount of the estimated future tax deductions arising from estimated returns and allowances, which can only be deducted for tax purposes when actual returns occur and allowances are granted, and which can only be realized if sufficient tax-basis income is generated in future periods to enable the deductions to be taken.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 11
-Subparagraph b
falsefalse6false0unh_DeferredTaxAssetsLongTermLiabilitiesunhfalsedebitinstantDeferred Tax Assets Long Term Liabilitiesfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse147000000147falsefalsefalsefalsefalse2truefalsefalse164000000164falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryDeferred Tax Assets Long Term LiabilitiesNo authoritative reference available.falsefalse7false0us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsPolicyholderLiabilitiesus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse102000000102falsefalsefalsefalsefalse2truefalsefalse218000000218falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe tax effect as of the balance sheet date of the amount of the estimated future tax deductions arising from estimated policyholder reserves, which will be deductible from future taxable income when actual costs are incurred, and which can only be realized if sufficient tax-basis income is generated in future periods to enable the tax deduction to be taken.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 11
-Subparagraph b
Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 17
-Subparagraph c, d
falsefalse8false0us-gaap_DeferredTaxAssetsDeferredIncomeus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse7800000078falsefalsefalsefalsefalse2truefalsefalse5800000058falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe tax effect as of the balance sheet date of the amount of the estimated future tax deductions attributable to income recognized only for tax purposes and which will reverse when recognized under generally accepted accounting principles.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 11
-Subparagraph c
falsefalse9false0unh_DeferredTaxAssetsUnrecognizedTaxBenefitsunhfalsedebitinstantDeferred tax assets, unrecognized tax benefits.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse6200000062falsefalsefalsefalsefalse2truefalsefalse5500000055falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryDeferred tax assets, unrecognized tax benefits.No authoritative reference available.falsefalse10false0us-gaap_DeferredTaxAssetsOtherus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse215000000215falsefalsefalsefalsefalse2truefalsefalse190000000190falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe tax effect as of the balance sheet date of the amount of estimated future tax deductions arising from other temporary differences not otherwise specified in the taxonomy.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43
falsefalse11false0us-gaap_DeferredTaxAssetsGrossus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse15070000001507falsefalsefalsefalsefalse2truefalsefalse15110000001511falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe sum of the tax effects as of the balance sheet date of the amounts of all future tax deductions arising from temporary differences between tax basis and generally accepted accounting principles basis recognition of assets, liabilities, revenues and expenses, which can only be deducted for tax purposes when permitted under enacted tax laws ( before the valuation allowance, if any, to reduce such sum amount to net realizable value). Includes any tax benefit realized in deferred tax assets for significant impacts of tax planning strategies.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43, 289
truefalse12false0us-gaap_DeferredTaxAssetsValuationAllowanceus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-247000000-247falsefalsefalsefalsefalse2truefalsefalse-198000000-198falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe sum of the portions of deferred tax assets as of the balance sheet date for which, based on the weight of available evidence, it is more likely than not will not be realized through future reductions of tax-based income.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 17
-Subparagraph e
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43-49
falsefalse13false0us-gaap_DeferredTaxAssetsNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse12600000001260falsefalsefalsefalsefalse2truefalsefalse13130000001313falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe aggregate tax effects as of the balance sheet date of all future tax deductions arising from temporary differences between tax basis and generally accepted accounting principles basis recognition of assets, liabilities, revenues and expenses, which can only be deducted for tax purposes when permitted under enacted tax laws; net of deducting the allocated valuation allowance, if any, to reduce such amount to net realizable value.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43
truefalse14false0us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssetsus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-1104000000-1104falsefalsefalsefalsefalse2truefalsefalse-890000000-890falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cumulative amount of the estimated future tax effects attributable to the difference between the tax basis of intangible assets and the basis of intangible assets computed in accordance with generally accepted accounting principles. The difference in basis, whether due to amortization or other reasons, will increase future taxable income when such difference reverses. Intangible assets include, but are not limited to, assets such as patents, trademarks and customer lists.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 11
-Subparagraph d
falsefalse15false0us-gaap_DeferredTaxLiabilitiesDeferredExpenseCapitalizedSoftwareus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-450000000-450falsefalsefalsefalsefalse2truefalsefalse-449000000-449falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount as of the balance sheet date of the estimated future tax effects attributable to the difference between the methods used to account for capitalized software for tax purposes and under generally accepted accounting principles.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 11
-Subparagraph d
falsefalse16false0us-gaap_DeferredTaxLiabilitiesOtherComprehensiveIncomeus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-161000000-161falsefalsefalsefalsefalse2truefalsefalse-163000000-163falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount as of the balance sheet date of the estimated future tax effects arising from unrealized gain on items included in other comprehensive income which will increase future taxable income when such gain is realized.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 36
-Subparagraph b
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 11
-Subparagraph a
falsefalse17false0us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipmentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-140000000-140falsefalsefalsefalsefalse2truefalsefalse-80000000-80falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount as of the balance sheet date of the estimated future tax effects attributable to the difference between the tax basis of capital assets and the basis of capital assets computed in accordance with generally accepted accounting principles. The difference in basis, attributable to different capitalization of costs, depreciation, or amortization methodologies, will increase future taxable income when such basis difference is realized. Capital assets include but are not limited to assets such as land, real estate, leasehold improvements, machinery and equipment and furniture and fixtures.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 11
-Subparagraph d, e, f
falsefalse18false0us-gaap_DeferredTaxLiabilitiesOtherus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-92000000-92falsefalsefalsefalsefalse2truefalsefalse-90000000-90falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cumulative amount of the estimated future tax effects attributable to other temporary differences not otherwise specified in this taxonomy that were expensed for tax purposes but capitalized in conformity with generally accepted accounting principles, or which were recognized as revenue under GAAP but not for tax purposes, which will reverse in future periods.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43
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-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 11
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falsefalse19false0us-gaap_DeferredTaxLiabilitiesus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegatedtotal1truefalsefalse-1947000000-1947falsefalsefalsefalsefalse2truefalsefalse-1672000000-1672falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cumulative amount of all deferred tax liabilities, which result from applying the applicable tax rate to net taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax. A taxable temporary difference is a difference between the tax basis and the carrying amount of an asset or liability in the financial statements prepared in accordance with generally accepted accounting principles that will result in taxable amounts in one or more future periods.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 42, 43
truefalse20false0us-gaap_DeferredTaxAssetsLiabilitiesNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse-687000000-687falsetruefalsefalsefalse2truefalsefalse-359000000-359falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor entities that net deferred tax assets and tax liabilities, represents the unclassified net amount of deferred tax assets and liabilities as of the balance sheet date, which result from applying the applicable enacted tax rate to net temporary differences and carryforwards pertaining to assets or liabilities. A temporary difference is a difference between the tax basis of an asset or liability and its carrying amount in the financial statements prepared in accordance with generally accepted accounting principles that will reverse in ensuing periods.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 42, 43
truefalse219Income Taxes (Components of deferred income tax assets and liabilities) (Details) (USD $)MillionsUnKnownUnKnownUnKnownfalsetrue
