2.2.0.25falsefalse40305 - Disclosure - Available-For-Sale Securities (Summary of Gross Realized Gains and Losses Related to Sales of Marketable Securities) (Details)truefalseIn Thousandsfalse1falsefalseUSDfalsefalse1/1/2011 - 3/31/2011
USD ($)
USD ($) / shares
$Duration_1_1_2011_To_3_31_2011http://www.sec.gov/CIK0000882095duration2011-01-01T00:00:002011-03-31T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit14Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit13Standardhttp://www.xbrl.org/2003/instancepurexbrli0Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit15Standardhttp://www.gilead.com/2011-03-31yearsgild0USDUSD$2falsefalseUSDfalsefalse1/1/2010 - 3/31/2010
USD ($)
USD ($) / shares
$Duration_1_1_2010_To_3_31_2010http://www.sec.gov/CIK0000882095duration2010-01-01T00:00:002010-03-31T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit14Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2true0us-gaap_AvailableForSaleSecuritiesAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalse3false0us-gaap_AvailableForSaleSecuritiesGrossRealizedGainsus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse36970003697falsetruefalsefalsefalse2truefalsefalse18340001834falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 21
-Subparagraph a
falsefalse4false0us-gaap_AvailableForSaleSecuritiesGrossRealizedLossesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-1362000-1362falsetruefalsefalsefalse2truefalsefalse-274000-274falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 21
-Subparagraph a
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