XML 48 R39.htm IDEA: XBRL DOCUMENT v3.23.3

Collaboration Agreements, License Agreement and Revenues - Summary of Revenue Recognized Under the Collaboration Agreements - Additional Information 4 (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
Europe [Member] | Astellas Agreement [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Transaction price, variable consideration from estimated future co-development billing		$ 800,000
Changes in revenue from changes to estimated variable consideration	$ 0
U.S./RoW and China [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Transaction price, variable consideration from estimated future co-development billing		$ 2,000,000
Changes in revenue from changes to estimated variable consideration	$ 0

X

- Definition

Variable consideration payment received from estimated future co-development billing.

+ References

No definition available.

+ Details

Name:	fgen_VariableConsiderationPaymentReceivedFromEstimatedFutureCoDevelopmentBilling
Namespace Prefix:	fgen_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of revenue recognized arising from contract liability from change in timeframe for performance obligation to be satisfied.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-10

+ Details

Name:	us-gaap_ContractWithCustomerLiabilityChangeInTimeframePerformanceObligationSatisfiedRevenueRecognized
Namespace Prefix:	us-gaap_
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_RevenueRecognitionMultipleDeliverableArrangementsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	srt_StatementGeographicalAxis=srt_EuropeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_TypeOfArrangementAxis=fgen_AstellasCollaborationAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=fgen_UnitedStatesRestOfWorldAndChinaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: