Name:	bysi_PercentageOfFullyDilutedEquityCapitalizationRequiredToBeIssuedAsSharesInLieuOfRoyaltyPayments
Namespace Prefix:	bysi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The requirement to issue shares in lieu of royalty payments if the Company offers an IPO within this time frame.

No definition available.

Name:	bysi_PeriodFollowingRoyaltyTerminationAgreementRequirementToIssueShares
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Data Type:	xbrli:durationItemType
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The percent of gross proceeds from the sale of product that is required to be paid out as royalties on a quarterly basis.

No definition available.

Name:	bysi_QuarterlyRoyaltyPaymentsRequiredAsAPercentageOfGrossProceedsOnSaleOfProduct
Namespace Prefix:	bysi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the amount of research and development expense related to patent acquired settled by shares issuance.

No definition available.

Name:	bysi_ResearchAndDevelopmentExpensesSettledBySharesIssuance
Namespace Prefix:	bysi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The number of shares issued in lieu of royalty payments.

No definition available.

Name:	bysi_StockIssuedInLieuOfRoyaltyPayments
Namespace Prefix:	bysi_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

The term in which royalty payments are due.

No definition available.

Name:	bysi_TermOfRoyaltyPayments
Namespace Prefix:	bysi_
Data Type:	xbrli:durationItemType
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Period Type:	duration

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-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

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Per share or per unit amount of equity securities issued.

No definition available.

Name:	us-gaap_SharesIssuedPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_PrivatePlacementMember
Namespace Prefix:
Data Type:	na
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Period Type:

Name:	us-gaap_CounterpartyNameAxis=bysi_NereusTrustMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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Namespace Prefix:
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