2.2.0.25truefalse41901 - Disclosure - Subsequent Events (Details)truefalsefalse1falsefalseUSDfalsefalse1/1/2010 - 1/31/2010 USD ($) $Duration_1_1_2010_To_1_31_2010http://www.sec.gov/CIK0000882095duration2010-01-01T00:00:002010-01-31T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2falsefalseUSDtruefalse{us-gaap_StatementClassOfStockAxis} : Stock Repurchase Program; $5B, 3-Year [Member] 1/1/2011 - 1/31/2011 USD ($) $Duration_1_1_2011_To_1_31_2011http://www.sec.gov/CIK0000882095duration2011-01-01T00:00:002011-01-31T00:00:00falsefalseStock Repurchase Program; $5B, 3-Year [Member]us-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldigild_StockRepurchaseProgram5b3YearMemberus-gaap_StatementClassOfStockAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3falsefalseUSDtruefalse{us-gaap_StatementClassOfStockAxis} : Stock Repurchase Program; $5B, 3-Year [Member] 5/1/2010 - 5/31/2010 USD ($) $Duration_5_1_2010_To_5_31_2010http://www.sec.gov/CIK0000882095duration2010-05-01T00:00:002010-05-31T00:00:00falsefalseStock Repurchase Program; $5B, 3-Year [Member]us-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldigild_StockRepurchaseProgram5b3YearMemberus-gaap_StatementClassOfStockAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$4falsefalseUSDtruefalse{us-gaap_BusinessAcquisitionAxis} : Arresto Biosciences, Inc. [Member] 1/14/2011 USD ($) $As_Of_1_14_2011http://www.sec.gov/CIK0000882095instant2011-01-14T00:00:000001-01-01T00:00:00falsefalseArresto Biosciences, Inc. [Member]us-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldigild_ArrestoBiosciencesIncMemberus-gaap_BusinessAcquisitionAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$5falsefalseUSDtruefalse{us-gaap_BusinessAcquisitionAxis} : Calistoga Pharmaceuticals, Inc. [Member] 2/1/2011 - 2/28/2011 USD ($) $Duration_2_1_2011_To_2_28_2011http://www.sec.gov/CIK0000882095duration2011-02-01T00:00:002011-02-28T00:00:00falsefalseCalistoga Pharmaceuticals, Inc. [Member]us-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldigild_CalistogaPharmaceuticalsIncMemberus-gaap_BusinessAcquisitionAxisexplicitMemberUnit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false0gild_MaximumRepurchaseAmountOfCommonStockThroughRepurchaseProgramgildfalsedebitdurationMaximum Repurchase Amount Of Common Stock Through Repurchase Programfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse10000000001000000000falsetruefalsefalsefalse2truefalsefalse50000000005000000000falsetruefalsetruefalse3truefalsefalse50000000005000000000falsetruefalsetruefalse4falsefalsefalse00falsefalsefalsetruefalse5falsefalsefalse00falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryMaximum Repurchase Amount Of Common Stock Through Repurchase ProgramNo authoritative reference available.falsefalse3false0gild_PotentialCashPaymentAtAcquisitionRelatedToAcquisitionTenderOffergildfalsedebitdurationPotential cash payment at acquisition related to acquisition tender offer.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsetruefalse5truefalsefalse375000000375000000falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryPotential cash payment at acquisition related to acquisition tender offer.No authoritative reference available.falsefalse4false0us-gaap_BusinessAcquisitionCostOfAcquiredEntityCashPaidus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalse4truefalsefalse225000000225000000falsefalsefalsetruefalse5falsefalsefalse00falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryAmount of cash paid to acquire the entity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 68 -Subparagraph f(1) Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph d falsefalse5false0gild_PotentialFuturePaymentsRelatedToAcquisitionTenderOffergildfalsecreditdurationPotential future payments related to acquisition tender offer.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsetruefalse5truefalsefalse225000000225000000falsetruefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryPotential future payments related to acquisition tender offer.No authoritative reference available.falsefalse54Subsequent Events (Details) (USD $)NoRoundingUnKnownUnKnownUnKnownfalsetrue