2.2.0.25falsefalse40502 - Disclosure - Property, Equipment and Capitalized Software (Summary of Property, Equipment and Capitalized Software) (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$2falsefalseUSDfalsefalse12/31/2009
USD ($)
USD ($) / shares
$As_Of_12_31_20093http://www.sec.gov/CIK0000731766instant2009-12-31T00:00:000001-01-01T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit14Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit13Standardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$2true0us-gaap_PropertyPlantAndEquipmentAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalse3false0us-gaap_Landus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse3800000038falsetruefalsefalsefalse2truefalsefalse3200000032falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount as of the balance sheet date of real estate held for productive use. This excludes land held for sale.No authoritative reference available.falsefalse4false0us-gaap_BuildingsAndImprovementsGrossus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse764000000764falsefalsefalsefalsefalse2truefalsefalse662000000662falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount as of the balance sheet date of long-lived, depreciable assets that include building structures held for productive use including any addition, improvement, or renovation to the structure, such as interior masonry, interior flooring, electrical, and plumbing.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 12
-Paragraph 5
falsefalse5false0unh_ComputerEquipmentGrossunhfalsedebitinstantComputer equipment, gross.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse14180000001418falsefalsefalsefalsefalse2truefalsefalse15040000001504falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryComputer equipment, gross.No authoritative reference available.falsefalse6false0us-gaap_FurnitureAndFixturesGrossus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse224000000224falsefalsefalsefalsefalse2truefalsefalse235000000235falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying amount at the balance sheet date for long-lived, depreciable asset commonly used in offices and stores. Examples include desks, chairs, and store fixtures.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 12
-Paragraph 5
falsefalse7false0unh_AccumulatedDepreciationPropertyPlantAndEquipmentunhfalsecreditinstantAccumulated Depreciation Property Plant And Equipmentfalsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-1417000000-1417falsefalsefalsefalsefalse2truefalsefalse-1487000000-1487falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAccumulated Depreciation Property Plant And EquipmentNo authoritative reference available.falsefalse8false0us-gaap_PropertyPlantAndEquipmentNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse10270000001027falsefalsefalsefalsefalse2truefalsefalse946000000946falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, and production equipment.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 13
-Subparagraph a
-Article 5
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 12
-Paragraph 5
-Subparagraph b, c
Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 8
-Article 7
truefalse9false0us-gaap_CapitalizedComputerSoftwareGrossus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse25350000002535falsefalsefalsefalsefalse2truefalsefalse24450000002445falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe carrying amount of gross capitalized computer software costs as of the balance sheet date.No authoritative reference available.falsefalse10false0us-gaap_CapitalizedComputerSoftwareAccumulatedAmortizationus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-1362000000-1362falsefalsefalsefalsefalse2truefalsefalse-1251000000-1251falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor each balance sheet presented, the amount of accumulated amortization for capitalized computer software costs.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Implementation Guide (Q and A)
-Number FAS86
-Paragraph 21
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 142
-Paragraph 45
falsefalse11false0us-gaap_CapitalizedComputerSoftwareNetus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse11730000001173falsefalsefalsefalsefalse2truefalsefalse11940000001194falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe carrying amount of capitalized computer software costs net of accumulated amortization as of the balance sheet date.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Implementation Guide (Q and A)
-Number FAS86
-Paragraph 18
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 86
-Paragraph 11
-Subparagraph a
truefalse12false0unh_PropertyPlantAndEquipmentNetIncludingCapitalizedComputerSoftwareNetunhfalsedebitinstantProperty plant and equipment net including capitalized computer software, netfalsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse22000000002200falsetruefalsefalsefalse2truefalsefalse21400000002140falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryProperty plant and equipment net including capitalized computer software, netNo authoritative reference available.truefalse211Property, Equipment and Capitalized Software (Summary of Property, Equipment and Capitalized Software) (Details) (USD $)MillionsUnKnownUnKnownUnKnownfalsetrue
