XML 91 R61.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Commitments and Contingencies - Additional Information (Detail) $ in Thousands | 1 Months Ended | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Feb. 28, 2013 USD ($) ft² | Sep. 30, 2006 USD ($) ft² $ / ft² | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Jun. 30, 2012 USD ($)
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |
Restricted time deposits |  |  | $ 4,145 | $ 5,181 |  | $ 4,145 | $ 5,181 |  |
FibroGen, Inc. [Member] |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |
Land subject to leases | ft² |  | 234,249 |  |  |  |  |  |  |
Initial term of lease contract |  | 15 years |  |  |  |  |  |  |
Restricted time deposits |  | $ 7,300 |  |  |  |  |  |  |
Percentage of letter of credit released |  |  |  |  | 0.125% |  |  |  |
Description of lessee leasing arrangements, operating leases |  |  |  |  |  | The agreement included an expansion option to occupy part of an adjacent building within 31 months of the lease commencement date of November 20, 2008. |  |  |
Lease incentive receivable from land lord through expansion option not used |  |  |  |  |  |  |  |  | $ 5,000
Percentage of construction costs for tenant improvement |  | 60.00% |  |  |  |  |  |  |
Tenant improvement price per square foot of rental space | $ / ft² |  | 140.50 |  |  |  |  |  |  |
Tenant improvements allowance of rental space |  | $ 32,500 |  |  |  |  |  |  |
Cost of construction capitalized |  | 50,800 |  |  |  |  |  |  |
Reimbursements from landlord for tenant improvements |  | $ 32,500 |  |  |  |  |  |  |
FibroGen, Inc. [Member] | Reclassified from Restricted Cash to Short-term Investments [Member] |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |
Prior period reclassification adjustment |  |  | $ 1,000 | $ 1,000 | $ 1,000 |  |  |  |
FibroGen China [Member] |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |
Land subject to leases | ft² | 4,820 |  |  |  |  |  |  |  |
Initial term of lease contract | 8 years |  |  |  |  |  |  |  |
Percentage of construction costs for tenant improvement | 100.00% |  |  |  |  |  |  |  |
Cost of construction capitalized | $ 3,100 |  |  |  |  |  |  |  |
Reimbursements from landlord for tenant improvements | $ 500 |  |  |  |  |  |  |  |
Lease starting date | Feb. 01, 2013 |  |  |  |  |  |  |  |
Rent expenses for leased facilities |  |  |  |  |  | $ 3,100 | 3,000 | $ 2,800 |
FibroGen China [Member] | Research and Development Expenses and General and Administrative Expenses [Member] |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |
Sublease income received |  |  |  |  |  | $ 3,500 | $ 3,900 | $ 3,800 |

X
- Definition Commitments and contingencies. + References No definition available. + Details
Name: | fgen_CommitmentsAndContingenciesLineItems
Namespace Prefix: | fgen_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Lease commencement date. + References No definition available. + Details
Name: | fgen_LeaseCommencementDate
Namespace Prefix: | fgen_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of letter of credit released. + References No definition available. + Details
Name: | fgen_PercentageOfLetterOfCreditReleased
Namespace Prefix: | fgen_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage responsibility of construction costs for tenant improvements. + References No definition available. + Details
Name: | fgen_PercentageResponsibilityOfConstructionCostsForTenantImprovements
Namespace Prefix: | fgen_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Reimbursements for tenant improvements. + References No definition available. + Details
Name: | fgen_ReimbursementsForTenantImprovements
Namespace Prefix: | fgen_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Restricted time deposits noncurrent. + References No definition available. + Details
Name: | fgen_RestrictedTimeDepositsNoncurrent
Namespace Prefix: | fgen_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Tenant Improvement Allowance Per Square Foot Of Rentable Space. + References No definition available. + Details
Name: | fgen_TenantImprovementAllowancePerSquareFootOfRentableSpace
Namespace Prefix: | fgen_
Data Type: | us-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition The expense charged against earnings for the periodic recognition of capitalized leases. This element may apply to energy companies that lease mineral producing properties and to other enterprises that capitalize property, plant, or equipment obtained through capital leases. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=84164758&loc=d3e45031-112735 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 + Details
Name: | us-gaap_AmortizationOfLeasedAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition A general description of the nature of the existing leasing arrangements of a lessee for all operating leases including, but not limited to: (1) rental escalation clauses; (2) renewal or purchase options; (3) guarantees or indemnities, if any, (4) restrictions imposed by lease arrangements; (5) unusual provisions or conditions; (6) contingent rentals, if any; and (7) lease expiration dates. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=84164451&loc=d3e36991-112694 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 10 -Section 55 -Paragraph 40 -Subparagraph (Note 1) -URI http://asc.fasb.org/extlink&oid=82846649&loc=d3e38371-112697 + Details
Name: | us-gaap_DescriptionOfLesseeLeasingArrangementsOperatingLeases
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Area of land subject to a ground lease. + References No definition available. + Details
Name: | us-gaap_LandSubjectToGroundLeases
Namespace Prefix: | us-gaap_
Data Type: | num:areaItemType
Balance Type: | na
Period Type: | instant

X
- Definition This item represents a receivable for an incentive or inducement contractually stipulated between parties to a lease whereby the lessor has committed to provide the entity (lessee) with a cash payment as inducement to enter the lease. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 25 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=77902458&loc=d3e40019-112707 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 25 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=77902458&loc=d3e40010-112707 + Details
Name: | us-gaap_LeaseIncentiveReceivable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount before accumulated depreciation of additions or improvements to assets held under a lease arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 4 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=82887183&loc=d3e6812-107765 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 + Details
Name: | us-gaap_LeaseholdImprovementsGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980 + Details
Name: | us-gaap_LesseeOperatingLeaseTermOfContract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Definition The amount of revenue recognized for the period under subleasing arrangements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 55 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=77891322&loc=d3e41620-112719 + Details
Name: | us-gaap_OperatingLeasesIncomeStatementSubleaseRevenue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=77902758&loc=d3e41499-112717 + Details
Name: | us-gaap_OperatingLeasesRentExpenseNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of a reclassification adjustment made to prior period financial statement amounts. + References No definition available. + Details
Name: | us-gaap_PriorPeriodReclassificationAdjustment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=fgen_FibroGenIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis=fgen_ReclassificationFromRestrictedCashToShortTermInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=fgen_FibroGenChinaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=fgen_ResearchAndDevelopmentAndGeneralAndAdministrativeExpensesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |