XML 45 R32.htm IDEA: XBRL DOCUMENT
v3.19.2

Collaboration and Other Agreements - NIAID Contract (Details) |  | 3 Months Ended | 6 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | ---
Sep. 15, 2015 USD ($) Molecule | Jun. 30, 2019 USD ($) | Jun. 30, 2018 USD ($) | Sep. 30, 2017 USD ($) | Jun. 30, 2019 USD ($) | Jun. 30, 2018 USD ($) | Sep. 30, 2018 USD ($) | Sep. 30, 2017 USD ($) | Dec. 31, 2017 USD ($)
Collaboration And Other Agreements [Line Items] |  |  |  |  |  |  |  |  |
Revenues |  | $ 10,593,000 | $ 18,834,000 |  | $ 20,255,000 | $ 23,529,000 |  |  |
NIAID |  |  |  |  |  |  |  |  |
Collaboration And Other Agreements [Line Items] |  |  |  |  |  |  |  |  |
Commercialization of molecules | Molecule | 2 |  |  |  |  |  |  |  |
Base period | $ 7,500,000 |  |  |  |  |  |  |  |
Additional development funding options under agreement | 17,000,000.0 |  |  |  |  |  |  |  |
Total potential value | $ 24,500,000 |  |  |  |  |  |  |  |
Proceeds from additional development funding options under agreement |  |  |  |  |  |  |  |  | $ 10,800,000
Revenues From Grants | NIAID |  |  |  |  |  |  |  |  |
Collaboration And Other Agreements [Line Items] |  |  |  |  |  |  |  |  |
Revenues |  |  |  | $ 200,000 | $ 600,000 | $ 600,000 | $ 800,000 | $ 400,000 |

X
- References No definition available. + Details
Name: | mgnx_AdditionalDevelopmentFundingOptionsUnderAgreement
Namespace Prefix: | mgnx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | mgnx_ExercisedAdditionalDevelopmentFundingOptionsUnderAgreement
Namespace Prefix: | mgnx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | mgnx_FundedValueOfBasePeriod
Namespace Prefix: | mgnx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | mgnx_NumberOfMoleculesToBeDevelopedAndCommercializedUnderAgreement
Namespace Prefix: | mgnx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | mgnx_TotalPotentialValueUnderAgreement
Namespace Prefix: | mgnx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 + Details
Name: | us-gaap_Revenues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | srt_CounterpartyNameAxis=mgnx_NationalInstituteOfAllergyAndInfectiousDiseasesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=mgnx_RevenuesFromGrantsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |