XML 52 R46.htm IDEA: XBRL DOCUMENT v3.24.3

Variable Interest Entities - Consolidated Variable Interest Entity - Additional Information (Detail) - USD ($) $ in Millions		3 Months Ended
	May 05, 2023	Mar. 31, 2024	Sep. 30, 2024
Third Party Shareholders [Member] | Nonredeemable NCI [Member]
Business Acquisition [Line Items]
Ownership percentage	100.00%		100.00%
Other Investors [Member] | Nonredeemable NCI [Member]
Business Acquisition [Line Items]
Ownership percentage	98.00%		98.00%
Series A Preferred Shares [Member] | Nonredeemable NCI [Member]
Business Acquisition [Line Items]
Ownership percentage	2.00%		2.00%
Fortis Therapeutics [Member]
Business Acquisition [Line Items]
Payment to options exercised	$ 80.0
Contingent payment associated with business acquisition	200.0
Product development obligations	$ 5.4	$ 1.7

X

- Definition

Payment to options exercised

+ References

No definition available.

+ Details

Name:	fgen_PaymentToOptionsExercised
Namespace Prefix:	fgen_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Product Development Costs

+ References

No definition available.

+ Details

Name:	fgen_ProductDevelopmentCosts
Namespace Prefix:	fgen_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-5

+ Details

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

X

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481687/323-10-50-3

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Amount of cash outflow, made soon after acquisition date of business combination, to settle contingent consideration liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 13
-Subparagraph (d)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-13

+ Details

Name:	us-gaap_PaymentForContingentConsiderationLiabilityInvestingActivities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	srt_OwnershipAxis=fgen_ThirdPartyShareholdersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=us-gaap_OtherInvesteesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_OwnershipAxis=fgen_OtherInvestorsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_SeriesAPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_BusinessAcquisitionAxis=fgen_FortisTherapeuticsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: