Note 14 - Segment Reporting and Geographic Information (Details Textual) - Seed [Member]	Dec. 13, 2025	Dec. 13, 2024
Minimum [Member]
Defined Benefit Plan, Plan Assets, Divestiture, Percentage	90.00%	90.00%
Maximum [Member]
Defined Benefit Plan, Plan Assets, Divestiture, Percentage	100.00%	100.00%

Represents the percentage of investment owned to be disposed.

No definition available.

Name:	bysi_InvestmentOwnedDisposalPercentage
Namespace Prefix:	bysi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant