XML 49 R38.htm IDEA: XBRL DOCUMENT
v3.20.2

Summary of significant accounting policies - Government grants (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019
Summary of significant accounting policies |  |  |  |
Proceeds from government grants | $ 2.8 |  | $ 2.8 |
Reduction of research and development | $ 0.1 | $ 0.2 | $ 0.3 | $ 0.5

X
- Definition Amount of reduction of research and development expense related to government grant arrangements. + References No definition available. + Details
Name: | bcyc_ReductionOfResearchAndDevelopmentExpenseRelatedToGovernmentGrantArrangements
Namespace Prefix: | bcyc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Carrying amount as of the balance sheet date of amounts due under the terms of governmental, corporate, or foundation grants. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.8) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_GrantsReceivable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant