XML 66 R53.htm IDEA: XBRL DOCUMENT v2.4.1.9
Collaboration and License Agreements - Additional Information 4 (Detail) (USD $)
1 Months Ended 12 Months Ended
Oct. 31, 2010
Molecule
Dec. 31, 2014
Payments
Dec. 31, 2013
Dec. 31, 2012
License And Collaboration Agreements [Line Items]        
Deferred revenue, Current   $ 14,248,000us-gaap_DeferredRevenueCurrent $ 20,267,000us-gaap_DeferredRevenueCurrent  
Deferred revenue, Long-term liabilities   16,472,000us-gaap_DeferredRevenueNoncurrent 7,136,000us-gaap_DeferredRevenueNoncurrent  
Boehringer [Member]        
License And Collaboration Agreements [Line Items]        
Collaboration agreement date   October 2010    
Commercialization of molecules 10mgnx_NumberOfMoleculesToBeDevelopedAndCommercializedAsPerCollaborations
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
     
Nonrefundable upfront payment 15,000,000mgnx_NonRefundableUpFrontPayment
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
     
Number of annual maintenance payments received   3mgnx_NumberOfAnnualMaintenancePaymentReceived
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
   
Clinical milestone payments   41,000,000mgnx_AdditionalPotentialClinicalMilestonePaymentsUnderAgreement
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
   
Regulatory milestone payments   89,000,000mgnx_AdditionalPotentialRegulatoryMilestonePaymentsUnderAgreement
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
   
Sales milestone payments   83,000,000mgnx_AdditionalPotentialSalesMilestonePaymentsUnderAgreement
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
   
Research obligation completion date   2015-09    
Recognized revenue under agreement   13,700,000us-gaap_LicensesRevenue
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
14,400,000us-gaap_LicensesRevenue
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
11,700,000us-gaap_LicensesRevenue
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
Deferred revenue     12,800,000us-gaap_DeferredRevenue
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
 
Deferred revenue, Current   5,800,000us-gaap_DeferredRevenueCurrent
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
7,000,000us-gaap_DeferredRevenueCurrent
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
 
Deferred revenue, Long-term liabilities     5,800,000us-gaap_DeferredRevenueNoncurrent
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
 
Milestone payment   $ 2,000,000us-gaap_RevenueRecognitionMilestoneMethodRevenueRecognized
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
$ 5,000,000us-gaap_RevenueRecognitionMilestoneMethodRevenueRecognized
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember
$ 2,000,000us-gaap_RevenueRecognitionMilestoneMethodRevenueRecognized
/ us-gaap_CounterpartyNameAxis
= mgnx_BoehringerIngelheimMember