Name:	BSFC_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentExercisedInPeriodWeightedAverageExercisePrice
Namespace Prefix:	BSFC_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

The number of shares into which fully or partially vested non-option equity outstanding as of the balance sheet date can be currently converted under the non-option equity plan.

No definition available.

Name:	BSFC_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableNumber
Namespace Prefix:	BSFC_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of non-option equity outstanding and currently exercisable under the non-option equity plan.

No definition available.

Name:	BSFC_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageExercisePrice
Namespace Prefix:	BSFC_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Share based compensation arrangement by share based payment award non option equity instruments forfeited expired in period weighted average exercise price.

No definition available.

Name:	BSFC_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitedExpiredInPeriodWeightedAverageExercisePrice
Namespace Prefix:	BSFC_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Weighted average per share amount at which grantees can acquire shares of common stock by exercise of non-option equity.

No definition available.

Name:	BSFC_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGrantsInPeriodWeightedAverageExercisePrice
Namespace Prefix:	BSFC_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Share based compensation arrangement by share based payment award non option equity instruments outstanding exercisable weighted average remaining contractual term.

No definition available.

Name:	BSFC_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingExercisableWeightedAverageRemainingContractualTerm
Namespace Prefix:	BSFC_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Weighted average price at which grantees can acquire the shares reserved for issuance under the stock non-option equity plan.

No definition available.

Name:	BSFC_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageExercisePrice
Namespace Prefix:	BSFC_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Share based compensation arrangement by share based payment award non option equity instruments outstanding weighted average remaining contractual term.

No definition available.

Name:	BSFC_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageRemainingContractualTerm
Namespace Prefix:	BSFC_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Sharebased compensation arrangement by sharebased payment award non options exercisable intrinsic value.

No definition available.

Name:	BSFC_SharebasedCompensationArrangementBySharebasedPaymentAwardNonOptionsExercisableIntrinsicValue1
Namespace Prefix:	BSFC_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Number of non-option equity instruments exercised by participants.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(02)
-SubTopic 10
-Topic 718
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Number of shares under non-option equity instrument agreements that were either cancelled or expired.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(03)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Net number of non-option equity instruments granted to participants.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(01)
-SubTopic 10
-Topic 718
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2