Concentrations of Credit Risk (Details) (USD $) In Millions, unless otherwise specified
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12 Months Ended |
Dec. 31, 2014
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Dec. 31, 2013
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Dec. 31, 2012
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Concentration Risk [Line Items] |
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Foreign exchange fluctuations gain (loss) |
0.5us-gaap_ForeignCurrencyTransactionGainLossBeforeTax |
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Diplomat Specialty Pharmacy [Member] | Accounts Receivable [Member] | Customer Concentration Risk [Member] |
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Concentration Risk [Line Items] |
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Concentration Risk, Percentage |
92.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_AccountsReceivableMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_MajorCustomersAxis = exel_DiplomatSpecialtyPharmacyMember |
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Diplomat Specialty Pharmacy [Member] | Sales [Member] | Customer Concentration Risk [Member] |
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Concentration Risk [Line Items] |
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Concentration Risk, Percentage |
99.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_SalesMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_MajorCustomersAxis = exel_DiplomatSpecialtyPharmacyMember |
45.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_SalesMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_MajorCustomersAxis = exel_DiplomatSpecialtyPharmacyMember |
0.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_SalesMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_MajorCustomersAxis = exel_DiplomatSpecialtyPharmacyMember |
Bristol-Myers Squibb [Member] | Revenue, Rights Granted [Member] | Customer Concentration Risk [Member] |
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Concentration Risk [Line Items] |
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Concentration Risk, Percentage |
0.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_RevenueRightsGrantedMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_MajorCustomersAxis = exel_BristolMyersSquibbMember |
52.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_RevenueRightsGrantedMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_MajorCustomersAxis = exel_BristolMyersSquibbMember |
66.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_RevenueRightsGrantedMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_MajorCustomersAxis = exel_BristolMyersSquibbMember |
Merck [Member] | Revenue, Rights Granted [Member] | Customer Concentration Risk [Member] |
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Concentration Risk [Line Items] |
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Concentration Risk, Percentage |
0.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_RevenueRightsGrantedMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_MajorCustomersAxis = exel_MerckMember |
0.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_RevenueRightsGrantedMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_MajorCustomersAxis = exel_MerckMember |
22.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_RevenueRightsGrantedMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_MajorCustomersAxis = exel_MerckMember |
Daiichi Sankyo [Member] | Revenue, Rights Granted [Member] | Customer Concentration Risk [Member] |
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Concentration Risk [Line Items] |
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Concentration Risk, Percentage |
0.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_RevenueRightsGrantedMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_MajorCustomersAxis = exel_DaiichiSankyoMember |
0.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_RevenueRightsGrantedMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_MajorCustomersAxis = exel_DaiichiSankyoMember |
12.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_RevenueRightsGrantedMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_MajorCustomersAxis = exel_DaiichiSankyoMember |
Sobi [Member] |
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Concentration Risk [Line Items] |
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Reduction to net product revenues |
2.3us-gaap_SalesDiscountsReturnsAndAllowancesGoods / us-gaap_MajorCustomersAxis = exel_SobiMember |
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United States [Member] | Sales [Member] | Geographic Concentration Risk [Member] |
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Concentration Risk [Line Items] |
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Concentration Risk, Percentage |
99.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_SalesMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_GeographicConcentrationRiskMember / us-gaap_StatementGeographicalAxis = country_US |
97.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_SalesMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_GeographicConcentrationRiskMember / us-gaap_StatementGeographicalAxis = country_US |
100.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_SalesMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_GeographicConcentrationRiskMember / us-gaap_StatementGeographicalAxis = country_US |
European Union [Member] | Sales [Member] | Geographic Concentration Risk [Member] |
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Concentration Risk [Line Items] |
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Concentration Risk, Percentage |
1.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_SalesMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_GeographicConcentrationRiskMember / us-gaap_StatementGeographicalAxis = us-gaap_EuropeanUnionMember |
3.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_SalesMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_GeographicConcentrationRiskMember / us-gaap_StatementGeographicalAxis = us-gaap_EuropeanUnionMember |
0.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByBenchmarkAxis = us-gaap_SalesMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_GeographicConcentrationRiskMember / us-gaap_StatementGeographicalAxis = us-gaap_EuropeanUnionMember |