Discount Factor

No definition available.

Name:	bgi_DiscountFactor
Namespace Prefix:	bgi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fee As Percentage Of Principal Amount Upon Conversion

+ References

No definition available.

+ Details

Name:	bgi_FeeAsPercentageOfPrincipalAmountUponConversion
Namespace Prefix:	bgi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Irrevocable letter of credit.

+ References

No definition available.

+ Details

Name:	bgi_IrrevocableLetterOfCredit
Namespace Prefix:	bgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Notice Of Nonrenewal Days

+ References

No definition available.

+ Details

Name:	bgi_NoticeOfNonrenewalPeriod
Namespace Prefix:	bgi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Purchase commitment percentage.

+ References

No definition available.

+ Details

Name:	bgi_PurchaseCommitmentPercentage
Namespace Prefix:	bgi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Related Party Transaction Additional Renewal Term

+ References

No definition available.

+ Details

Name:	bgi_RelatedPartyTransactionAdditionalRenewalTerm
Namespace Prefix:	bgi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Related Party Transaction Agreement Effective Date

+ References

No definition available.

+ Details

Name:	bgi_RelatedPartyTransactionAgreementEffectiveDate
Namespace Prefix:	bgi_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Related Party Transaction Payments To Related Party

+ References

No definition available.

+ Details

Name:	bgi_RelatedPartyTransactionPaymentsToRelatedParty
Namespace Prefix:	bgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Related Party Transaction Term Of Agreement

+ References

No definition available.

+ Details

Name:	bgi_RelatedPartyTransactionTermOfAgreement
Namespace Prefix:	bgi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_AccountsPayableRelatedPartiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of accounts payable to related parties, due after one year or beyond the normal operating cycle, if longer.

+ References

No definition available.

+ Details

Name:	us-gaap_AccountsPayableRelatedPartiesNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionPrice1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of the fee that accompanies borrowing money under the debt instrument.

+ References

+ Details

Name:	us-gaap_DebtInstrumentFeeAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The average effective interest rate during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeFixedInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Portion of the carrying amount as of the balance sheet date of obligations due all related parties that is payable after one year or beyond the normal operating cycle if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.23)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_DueToRelatedPartiesNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

+ Details

Name:	us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash inflow from the issuance of common stock, preferred stock, treasury stock, stock options, and other types of equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromIssuanceOrSaleOfEquity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow from a long-term borrowing made from related parties where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth. Alternate caption: Proceeds from Advances from Affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

Name:	us-gaap_ProceedsFromRelatedPartyDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Date of maturity or expiration of arrangements with a related party (for example, but not limited to, leasing and debt arrangements between related parties), in CCYY-MM-DD format.

+ References

No definition available.

+ Details

Name:	us-gaap_RelatedPartyTransactionDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

+ Details

Name:	us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

Purchases during the period (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

No definition available.

+ Details

Name:	us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash outflow for the payment of a long-term borrowing made from a related party where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth. Alternate caption: Payments for Advances from Affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3291-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

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

- Definition

Number of shares issued during the period as a result of the conversion of convertible securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-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=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29-30)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

+ Details

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

- Definition

The gross value of stock issued during the period upon the conversion of convertible securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29-31)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-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=27012166&loc=d3e187085-122770

+ Details

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

- Details

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

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=bgi_MontrovestMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=bgi_PotentialTransactionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=bgi_GestofiMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=bgi_PrimeInvestmentsSaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=bgi_RegaluxeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Related party transactions - Additional Information (Detail)			1 Months Ended														12 Months Ended
	Nov. 17, 2015	Jun. 08, 2011 EUR (€)	Jun. 30, 2016	Apr. 30, 2015	Feb. 28, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2014 CHF (SFr)	Aug. 31, 2013 USD ($) $ / shares shares	Aug. 31, 2012 USD ($)	Jun. 30, 2011 USD ($)	Apr. 30, 2011	Jun. 30, 2009 USD ($)	Jun. 30, 2009 CAD	May 31, 2009 USD ($)	Feb. 28, 2009 USD ($)	Aug. 31, 2002	Mar. 26, 2016 USD ($)	Mar. 26, 2016 EUR (€)	Mar. 28, 2015 USD ($)	Mar. 28, 2015 EUR (€)	Mar. 29, 2014 USD ($)	Mar. 29, 2014 EUR (€)	Mar. 30, 2013 USD ($)	Feb. 28, 2015 CAD
Related Party Transaction [Line Items]
Legal fees incurred					$ 60,000												$ 38,000		$ 447,000		$ 57,000			CAD 75,000
Percentage of purchase price on cost																45.00%
Purchase price of diamonds																	503,000		189,000		0
Related party expenses																	201,000		241,000		237,000
Debentures converted to voting shares, value								$ 5,000,000
Annual interest rate of debentures								6.00%
Class A Common Stock [Member]
Related Party Transaction [Line Items]
Debentures converted to voting shares \| shares								2,941,085
Voting shares conversion price \| $ / shares								$ 1.70
Scenario, Forecast [Member]
Related Party Transaction [Line Items]
Agreement additional renewal term			1 year
Montrovest BV [Member]
Related Party Transaction [Line Items]
Amount paid to related party		€ 140,000															116,000	€ 105,000	$ 178,000	€ 140,000	188,000	€ 140,000
Notice days for non renewal		60 days
Agreement additional renewal term				1 year
Irrevocable letter of credit					5,000,000
Agreement expiration date	Dec. 31, 2015
Cash received from related party														$ 3,000,000	$ 2,000,000
Annual interest rate										11.00%									16.00%	16.00%
Effective interest rate										12.20%									17.80%
Fee as a percentage of outstanding principal amount																			7.00%	7.00%
Cash received from related party										$ 5,000,000
Transaction amount										75,000
Partial repayment of cash advance									$ 3,500,000
Advances payable to related party																	1,500,000		$ 1,500,000
Debentures converted to voting shares \| shares								2,828,634
Montrovest BV [Member] \| Class A Common Stock [Member]
Related Party Transaction [Line Items]
Debentures converted to voting shares, value								$ 4,800,000
Montrovest BV [Member] \| Minimum [Member] \| Potential Transaction [Member]
Related Party Transaction [Line Items]
Net cash proceeds from an equity issuance										$ 5,000,000
Gestofi [Member]
Related Party Transaction [Line Items]
Amount paid to related party																	39,000	€ 35,000
Agreement additional renewal term						1 year	1 year					1 year	1 year
Agreement beginning date	Jan. 01, 2016											Aug. 01, 2009	Aug. 01, 2009
Related party expenses					$ 12,500	$ 13,310	SFr 13,000					$ 10,324	CAD 13,700
Prime Investments S.A. [Member]
Related Party Transaction [Line Items]
Purchase price of diamonds																	$ 500,000		200,000
Ownership percentage																	15.00%
Regaluxe [Member]
Related Party Transaction [Line Items]
Amount paid to related party																	$ 0		0		1,000
Agreement additional renewal term																	1 year	1 year
Agreement expiration date											Mar. 30, 2013
Agreement beginning date											Apr. 01, 2011
Related party expenses																	$ 201,000		$ 241,000		237,000
Related party agreement term											1 year
Discount factor											3.50%
Regaluxe [Member] \| Maximum [Member]
Related Party Transaction [Line Items]
Related party expenses																					$ 260,000		$ 250,000