2.4.0.84021 - Disclosure - Summary of Significant Accounting Policies (Details 2)truefalseIn Thousands, unless otherwise specifiedfalse1false USDfalsefalse$D2013Q2YTDhttp://www.sec.gov/CIK0001235010duration2013-01-01T00:00:002013-06-30T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDtruefalse$I2013Q2_EstimateOfFairValueFairValueDisclosureMember_FairValueMeasurementsRecurringMemberhttp://www.sec.gov/CIK0001235010instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseFair valueus-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EstimateOfFairValueFairValueDisclosureMemberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3false USDtruefalse$I2012_EstimateOfFairValueFairValueDisclosureMember_FairValueMeasurementsRecurringMemberhttp://www.sec.gov/CIK0001235010instant2012-12-31T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseFair valueus-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EstimateOfFairValueFairValueDisclosureMemberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$4false USDtruefalse$I2013Q2_EstimateOfFairValueFairValueDisclosureMember_FairValueMeasurementsRecurringMember_CashEquivalentsMemberhttp://www.sec.gov/CIK0001235010instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseFair valueus-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EstimateOfFairValueFairValueDisclosureMemberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseCash equivalentsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashEquivalentsMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$5false USDtruefalse$I2012_EstimateOfFairValueFairValueDisclosureMember_FairValueMeasurementsRecurringMember_CashEquivalentsMemberhttp://www.sec.gov/CIK0001235010instant2012-12-31T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseFair valueus-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EstimateOfFairValueFairValueDisclosureMemberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseCash equivalentsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashEquivalentsMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$6false USDtruefalse$I2013Q2_EstimateOfFairValueFairValueDisclosureMember_FairValueMeasurementsRecurringMember_USGovernmentSponsoredEnterprisesDebtSecuritiesMemberhttp://www.sec.gov/CIK0001235010instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseFair valueus-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EstimateOfFairValueFairValueDisclosureMemberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseU.S. Government-sponsored enterprise obligationsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$7false USDtruefalse$I2012_EstimateOfFairValueFairValueDisclosureMember_FairValueMeasurementsRecurringMember_USGovernmentSponsoredEnterprisesDebtSecuritiesMemberhttp://www.sec.gov/CIK0001235010instant2012-12-31T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseFair valueus-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EstimateOfFairValueFairValueDisclosureMemberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseU.S. Government-sponsored enterprise obligationsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$8false USDtruefalse$I2013Q2_EstimateOfFairValueFairValueDisclosureMember_FairValueMeasurementsRecurringMember_CorporateDebtSecuritiesMemberhttp://www.sec.gov/CIK0001235010instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseFair valueus-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EstimateOfFairValueFairValueDisclosureMemberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseCorporate debt securitiesus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CorporateDebtSecuritiesMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$9false USDtruefalse$I2012_EstimateOfFairValueFairValueDisclosureMember_FairValueMeasurementsRecurringMember_CorporateDebtSecuritiesMemberhttp://www.sec.gov/CIK0001235010instant2012-12-31T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseFair valueus-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EstimateOfFairValueFairValueDisclosureMemberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseCorporate debt securitiesus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CorporateDebtSecuritiesMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$10false USDtruefalse$I2013Q2_EstimateOfFairValueFairValueDisclosureMember_FairValueMeasurementsRecurringMember_CommercialPaperNotIncludedWithCashAndCashEquivalentsMemberhttp://www.sec.gov/CIK0001235010instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseFair valueus-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EstimateOfFairValueFairValueDisclosureMemberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseCommercial paper obligationsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CommercialPaperNotIncludedWithCashAndCashEquivalentsMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$11false USDtruefalse$I2012_EstimateOfFairValueFairValueDisclosureMember_FairValueMeasurementsRecurringMember_CommercialPaperNotIncludedWithCashAndCashEquivalentsMemberhttp://www.sec.gov/CIK0001235010instant2012-12-31T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseFair valueus-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EstimateOfFairValueFairValueDisclosureMemberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseCommercial paper obligationsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CommercialPaperNotIncludedWithCashAndCashEquivalentsMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$12false USDtruefalse$I2013Q2_EstimateOfFairValueFairValueDisclosureMember_FairValueMeasurementsRecurringMember_ForeignGovernmentDebtMemberhttp://www.sec.gov/CIK0001235010instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseFair valueus-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EstimateOfFairValueFairValueDisclosureMemberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseForeign government bondsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignGovernmentDebtMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$13false USDtruefalse$I2012_EstimateOfFairValueFairValueDisclosureMember_FairValueMeasurementsRecurringMember_ForeignGovernmentDebtMemberhttp://www.sec.gov/CIK0001235010instant2012-12-31T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseFair valueus-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EstimateOfFairValueFairValueDisclosureMemberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseForeign government bondsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignGovernmentDebtMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$14false USDtruefalse$I2013Q2_FairValueInputsLevel1Member_FairValueMeasurementsRecurringMemberhttp://www.sec.gov/CIK0001235010instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseQuoted Prices in Active Markets (Level 1)us-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$15false USDtruefalse$I2012_FairValueInputsLevel1Member_FairValueMeasurementsRecurringMemberhttp://www.sec.gov/CIK0001235010instant2012-12-31T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseQuoted Prices in Active Markets (Level 1)us-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$16false USDtruefalse$I2013Q2_FairValueInputsLevel1Member_FairValueMeasurementsRecurringMember_CashEquivalentsMemberhttp://www.sec.gov/CIK0001235010instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseQuoted Prices in Active Markets (Level 1)us-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseCash equivalentsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashEquivalentsMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$17false USDtruefalse$I2012_FairValueInputsLevel1Member_FairValueMeasurementsRecurringMember_CashEquivalentsMemberhttp://www.sec.gov/CIK0001235010instant2012-12-31T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseQuoted Prices in Active Markets (Level 1)us-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseCash equivalentsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashEquivalentsMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$18false USDtruefalse$I2013Q2_FairValueInputsLevel2Member_FairValueMeasurementsRecurringMemberhttp://www.sec.gov/CIK0001235010instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$19false USDtruefalse$I2012_FairValueInputsLevel2Member_FairValueMeasurementsRecurringMemberhttp://www.sec.gov/CIK0001235010instant2012-12-31T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$20false USDtruefalse$I2013Q2_FairValueInputsLevel2Member_FairValueMeasurementsRecurringMember_USGovernmentSponsoredEnterprisesDebtSecuritiesMemberhttp://www.sec.gov/CIK0001235010instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseU.S. Government-sponsored enterprise obligationsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$21false USDtruefalse$I2012_FairValueInputsLevel2Member_FairValueMeasurementsRecurringMember_USGovernmentSponsoredEnterprisesDebtSecuritiesMemberhttp://www.sec.gov/CIK0001235010instant2012-12-31T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseU.S. Government-sponsored enterprise obligationsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$22false USDtruefalse$I2013Q2_FairValueInputsLevel2Member_FairValueMeasurementsRecurringMember_CorporateDebtSecuritiesMemberhttp://www.sec.gov/CIK0001235010instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseCorporate debt securitiesus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CorporateDebtSecuritiesMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$23false USDtruefalse$I2012_FairValueInputsLevel2Member_FairValueMeasurementsRecurringMember_CorporateDebtSecuritiesMemberhttp://www.sec.gov/CIK0001235010instant2012-12-31T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseCorporate debt securitiesus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CorporateDebtSecuritiesMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$24false USDtruefalse$I2013Q2_FairValueInputsLevel2Member_FairValueMeasurementsRecurringMember_CommercialPaperNotIncludedWithCashAndCashEquivalentsMemberhttp://www.sec.gov/CIK0001235010instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseCommercial paper obligationsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CommercialPaperNotIncludedWithCashAndCashEquivalentsMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$25false USDtruefalse$I2012_FairValueInputsLevel2Member_FairValueMeasurementsRecurringMember_CommercialPaperNotIncludedWithCashAndCashEquivalentsMemberhttp://www.sec.gov/CIK0001235010instant2012-12-31T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseCommercial paper obligationsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CommercialPaperNotIncludedWithCashAndCashEquivalentsMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$26false USDtruefalse$I2013Q2_FairValueInputsLevel2Member_FairValueMeasurementsRecurringMember_ForeignGovernmentDebtMemberhttp://www.sec.gov/CIK0001235010instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseForeign government bondsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignGovernmentDebtMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$27false USDtruefalse$I2012_FairValueInputsLevel2Member_FairValueMeasurementsRecurringMember_ForeignGovernmentDebtMemberhttp://www.sec.gov/CIK0001235010instant2012-12-31T00:00:000001-01-01T00:00:00falsefalseRecurringus-gaap_FairValueByMeasurementFrequencyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueMeasurementsRecurringMemberus-gaap_FairValueByMeasurementFrequencyAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_FairValueByFairValueHierarchyLevelAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_FairValueByFairValueHierarchyLevelAxisexplicitMemberfalsefalseForeign government bondsus-gaap_InvestmentTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignGovernmentDebtMemberus-gaap_InvestmentTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 3us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse6falsefalsefalse00falsefalsefalse7falsefalsefalse00falsefalsefalse8falsefalsefalse00falsefalsefalse9falsefalsefalse00falsefalsefalse10falsefalsefalse00falsefalsefalse11falsefalsefalse00falsefalsefalse12falsefalsefalse00falsefalsefalse13falsefalsefalse00falsefalsefalse14falsefalsefalse00falsefalsefalse15falsefalsefalse00falsefalsefalse16falsefalsefalse00falsefalsefalse17falsefalsefalse00falsefalsefalse18falsefalsefalse00falsefalsefalse19falsefalsefalse00falsefalsefalse20falsefalsefalse00falsefalsefalse21falsefalsefalse00falsefalsefalse22falsefalsefalse00falsefalsefalse23falsefalsefalse00falsefalsefalse24falsefalsefalse00falsefalsefalse25falsefalsefalse00falsefalsefalse26falsefalsefalse00falsefalsefalse27falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Fair Value Measurements2false 4us-gaap_AssetsFairValueDisclosureus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truefalsefalse296007000296007USD$falsetruefalse3truefalsefalse335553000335553USD$falsetruefalse4truefalsefalse2236100022361USD$falsetruefalse5truefalsefalse4794000047940USD$falsetruefalse6truefalsefalse5379300053793USD$falsetruefalse7truefalsefalse5122500051225USD$falsetruefalse8truefalsefalse119801000119801USD$falsetruefalse9truefalsefalse158913000158913USD$falsetruefalse10truefalsefalse6663400066634USD$falsetruefalse11truefalsefalse6513800065138USD$falsetruefalse12truefalsefalse3341800033418USD$falsetruefalse13truefalsefalse1233700012337USD$falsetruefalse14truefalsefalse2236100022361USD$falsetruefalse15truefalsefalse4794000047940USD$falsetruefalse16truefalsefalse2236100022361USD$falsetruefalse17truefalsefalse4794000047940USD$falsetruefalse18truefalsefalse273646000273646USD$falsetruefalse19truefalsefalse287613000287613USD$falsetruefalse20truefalsefalse5379300053793USD$falsetruefalse21truefalsefalse5122500051225USD$falsetruefalse22truefalsefalse119801000119801USD$falsetruefalse23truefalsefalse158913000158913USD$falsetruefalse24truefalsefalse6663400066634USD$falsetruefalse25truefalsefalse6513800065138USD$falsetruefalse26truefalsefalse3341800033418USD$falsetruefalse27truefalsefalse1233700012337USD$falsetruefalsexbrli:monetaryItemTypemonetaryThis element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 false2Assets fair value3false 4us-gaap_FairValueAssetsLevel1ToLevel2TransfersAmountus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse6falsefalsefalse00falsefalsefalse7falsefalsefalse00falsefalsefalse8falsefalsefalse00falsefalsefalse9falsefalsefalse00falsefalsefalse10falsefalsefalse00falsefalsefalse11falsefalsefalse00falsefalsefalse12falsefalsefalse00falsefalsefalse13falsefalsefalse00falsefalsefalse14falsefalsefalse00falsefalsefalse15falsefalsefalse00falsefalsefalse16falsefalsefalse00falsefalsefalse17falsefalsefalse00falsefalsefalse18falsefalsefalse00falsefalsefalse19falsefalsefalse00falsefalsefalse20falsefalsefalse00falsefalsefalse21falsefalsefalse00falsefalsefalse22falsefalsefalse00falsefalsefalse23falsefalsefalse00falsefalsefalse24falsefalsefalse00falsefalsefalse25falsefalsefalse00falsefalsefalse26falsefalsefalse00falsefalsefalse27falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of transfers of assets measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 false2Transfer from Level 1 to Level 2, assets4false 4us-gaap_FairValueAssetsLevel2ToLevel1TransfersAmountus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse6falsefalsefalse00falsefalsefalse7falsefalsefalse00falsefalsefalse8falsefalsefalse00falsefalsefalse9falsefalsefalse00falsefalsefalse10falsefalsefalse00falsefalsefalse11falsefalsefalse00falsefalsefalse12falsefalsefalse00falsefalsefalse13falsefalsefalse00falsefalsefalse14falsefalsefalse00falsefalsefalse15falsefalsefalse00falsefalsefalse16falsefalsefalse00falsefalsefalse17falsefalsefalse00falsefalsefalse18falsefalsefalse00falsefalsefalse19falsefalsefalse00falsefalsefalse20falsefalsefalse00falsefalsefalse21falsefalsefalse00falsefalsefalse22falsefalsefalse00falsefalsefalse23falsefalsefalse00falsefalsefalse24falsefalsefalse00falsefalsefalse25falsefalsefalse00falsefalsefalse26falsefalsefalse00falsefalsefalse27falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 false2Transfer from Level 2 to Level 1, assets5false 4us-gaap_ImpairmentOfInvestmentsus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse00USD$falsetruefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse6falsefalsefalse00falsefalsefalse7falsefalsefalse00falsefalsefalse8falsefalsefalse00falsefalsefalse9falsefalsefalse00falsefalsefalse10falsefalsefalse00falsefalsefalse11falsefalsefalse00falsefalsefalse12falsefalsefalse00falsefalsefalse13falsefalsefalse00falsefalsefalse14falsefalsefalse00falsefalsefalse15falsefalsefalse00falsefalsefalse16falsefalsefalse00falsefalsefalse17falsefalsefalse00falsefalsefalse18falsefalsefalse00falsefalsefalse19falsefalsefalse00falsefalsefalse20falsefalsefalse00falsefalsefalse21falsefalsefalse00falsefalsefalse22falsefalsefalse00falsefalsefalse23falsefalsefalse00falsefalsefalse24falsefalsefalse00falsefalsefalse25falsefalsefalse00falsefalsefalse26falsefalsefalse00falsefalsefalse27falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 16 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 15D -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 15C -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 35 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=16383099&loc=d3e25351-111560 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 16B -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-2/124-2 -Paragraph 22 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Other-than-temporary impairmentfalseSummary of Significant Accounting Policies (Details 2) (USD $)ThousandsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.momentapharma.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails2275