Collaboration Agreements - AG-881 Agreements (Details) - AG-881 program licenses - USD ($)	Apr. 27, 2015	Dec. 31, 2017
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Initial payment received	$ 10,000,000
Milestone-based receivable payments, eligible to be received	70,000,000
Milestone payment for filing of first NDA	15,000,000	$ 15,000,000
Milestone payments upon achievement of specified regulatory milestone events	$ 55,000,000

Portion of potential milestone payment receivable for filing of new drug application.

No definition available.

Name:	agio_PortionOfPotentialMilestonePaymentReceivableForFilingOfNewDrugApplication
Namespace Prefix:	agio_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Portion of potential milestone payment receivable for specified regulatory milestone events program.

+ References

No definition available.

+ Details

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Namespace Prefix:	agio_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Revenue Recognition, Milestone Method, Eligible Receivable

+ References

No definition available.

+ Details

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Namespace Prefix:	agio_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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Period Type:	duration

- Definition

Amount of deferred revenue recognized for transactions arising during the current reporting period. Deferred revenue is a liability as of the balance sheet date related to a revenue producing activity for which revenue has not yet been recognized. Generally, an Entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 13.A.4(a).Q1)
-URI http://asc.fasb.org/extlink&oid=65893310&loc=d3e214044-122780

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 13.A.3)
-URI http://asc.fasb.org/extlink&oid=65893310&loc=d3e214044-122780

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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Namespace Prefix:
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Balance Type:
Period Type: