Share Based Compensation Arrangement By Share-Based Payment Award, Non-Option Equity Instruments, Exercisable

No definition available.

Name:	bgsf_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisable
Namespace Prefix:	bgsf_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Intrinsic Value [Roll Forward]

+ References

No definition available.

+ Details

Name:	bgsf_SharebasedCompensationArrangementbySharebasedPaymentAwardNonOptionEquityInstrumentsIntrinsicValueRollForward
Namespace Prefix:	bgsf_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Intrinsic Value

+ References

No definition available.

+ Details

Name:	bgsf_SharebasedCompensationArrangementbySharebasedPaymentAwardNonOptionEquityInstrumentsOutstandingIntrinsicValue
Namespace Prefix:	bgsf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Weighted Average Exercise Price

+ References

No definition available.

+ Details

Name:	bgsf_SharebasedCompensationArrangementbySharebasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageExercisePrice
Namespace Prefix:	bgsf_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Weighted Average Remaining Contractual Life

+ References

No definition available.

+ Details

Name:	bgsf_SharebasedCompensationArrangementbySharebasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageRemainingContractualLife
Namespace Prefix:	bgsf_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Vested and Expected to Vest, Exercisable, Intrinsic Value

+ References

No definition available.

+ Details

Name:	bgsf_SharebasedCompensationArrangementbySharebasedPaymentAwardNonOptionEquityInstrumentsVestedandExpectedtoVestExercisableIntrinsicValue
Namespace Prefix:	bgsf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Vested and Expected to Vest, Exercisable, Weighted Average Exercise Price

+ References

No definition available.

+ Details

Name:	bgsf_SharebasedCompensationArrangementbySharebasedPaymentAwardNonOptionEquityInstrumentsVestedandExpectedtoVestExercisableWeightedAverageExercisePrice
Namespace Prefix:	bgsf_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Vested and Expected to Vest, Exercisable, Weighted Average Remaining Contractual Life

+ References

No definition available.

+ Details

Name:	bgsf_SharebasedCompensationArrangementbySharebasedPaymentAwardNonOptionEquityInstrumentsVestedandExpectedtoVestExercisableWeightedAverageRemainingContractualLife
Namespace Prefix:	bgsf_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Weighted Average Exercise Price [Roll Forward]

+ References

No definition available.

+ Details

Name:	bgsf_SharebasedCompensationArrangementbySharebasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageExercisePriceRollForward
Namespace Prefix:	bgsf_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

+ Details

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

- Definition

Per share or unit weighted-average intrinsic value of award forfeited under share-based payment arrangement. Excludes share and unit options.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresIntrinsicValue
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of share options (or share units) exercised during the current period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 3: 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(28))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 4: 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(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21463-112644

+ Details

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

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_WarrantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

SHARE-BASED COMPENSATION - Summary of Warrant Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	9 Months Ended
	Jun. 27, 2021	Sep. 26, 2021	Dec. 27, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Number of warrants, exercisable			25,862
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Weighted Average Exercise Price [Roll Forward]
Forfeited, weighted average exercise price, (in dollars per share)		$ 16.80
Exercisable warrants, weighted average exercise price (in dollars per share)			$ 16.80
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Intrinsic Value [Roll Forward]
Options converted		600
Warrant
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Number of warrants, outstanding, beginning balance (in shares)	25,862	25,862
Forfeited (in shares)		(25,862)
Number of warrants, outstanding, ending balance (in shares)		0
Number of warrants, exercisable		0
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Weighted Average Exercise Price [Roll Forward]
Outstanding warrants, weighted average exercise price, beginning balance (in dollars per share)	$ 16.80	$ 16.80
Outstanding warrants, weighted average exercise price, ending balance (in dollars per share)		0
Exercisable warrants, weighted average exercise price (in dollars per share)		$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Warrants outstanding, weighted average remaining contractual life	4 months 24 days	0 years
Exercisable warrants, weighted average remaining contractual life	4 months 24 days	0 years
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Intrinsic Value [Roll Forward]
Outstanding warrants, intrinsic value, beginning balance	$ 0	$ 0
Outstanding warrants, intrinsic value, ending balance		0
Exercisable warrants, intrinsic price		$ 0	$ 0