XML 57 R50.htm IDEA: XBRL DOCUMENT v3.21.4

Note 14 - Contingently Redeemable Noncontrolling Interests (Details Textual) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021 USD ($) $ / shares	Sep. 30, 2021 USD ($) $ / shares
Temporary Equity, Accretion to Redemption Value		$ 158
Series A-2 Preferred Shares [Member] | Research Collaboration and License Agreement with Eli Lilly [Member] | SEED Therapeutics Inc. [Member]
Temporary Equity, Stock Issued During Period, Value, New Issues		$ 0
Share Price (in dollars per share) | $ / shares	$ 0.50	$ 0.50
Convertible Instrument, Conversion Price (in dollars per share) | $ / shares	$ 2.5125	$ 2.5125
Temporary Equity, Accretion to Redemption Value	$ 96	$ 158

X

- Definition

The price per share of the conversion feature embedded in the convertible instrument.

+ References

No definition available.

+ Details

Name:	bysi_ConvertibleInstrumentConversionPrice
Namespace Prefix:	bysi_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

Name:	us-gaap_SharePrice
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Value of accretion of temporary equity to its redemption value during the period.

+ References

No definition available.

+ Details

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

X

- Definition

Value of new stock classified as temporary equity issued during the period.

+ References

No definition available.

+ Details

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

X

- Details

Name:	us-gaap_StatementClassOfStockAxis=bysi_SeriesA2PreferredSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

Name:	dei_LegalEntityAxis=bysi_SEEDTherapeuticsIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: