Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

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

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

+ Details

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

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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

- Details

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- Details

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Balance Type:
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- Details

Name:	us-gaap_LineOfCreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
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Balance Type:
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- Details

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- Details

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- Details

Name:	us-gaap_CreditFacilityAxis=brg_EquityCreditFacilityMember
Namespace Prefix:
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Balance Type:
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- Details

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Namespace Prefix:
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- Details

Name:	us-gaap_ShortTermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=brg_SeniorCreditFacilityMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_CreditFacilityAxis=brg_TermLoanFacilityMember
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Revolving credit facility (Details Textual) - USD ($) $ in Millions				1 Months Ended	12 Months Ended
	Dec. 21, 2018	Nov. 09, 2018	Oct. 04, 2017	Mar. 20, 2018	Dec. 31, 2018	Dec. 28, 2018
Debt Instrument, Description of Variable Rate Basis		LIBOR plus 2.50%
Debt Instrument, Basis Spread on Variable Rate					1.75%
Minimum [Member]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.35%
Maximum [Member]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.40%
Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 50.0
Debt Instrument, Description of Variable Rate Basis	LIBOR plus 3.5%
Debt Instrument, Maturity Date	Dec. 21, 2019
Debt, Weighted Average Interest Rate					5.94%
Line of Credit Facility, Remaining Borrowing Capacity					$ 48.3
Revolving Credit Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Description of Variable Rate Basis	LIBOR plus 3.5%
Debt Instrument, Basis Spread on Variable Rate	3.50%
Revolving Credit Facility [Member] \| Base Rate [Member]
Debt Instrument, Description of Variable Rate Basis	base rate plus 2.5%
Debt Instrument, Basis Spread on Variable Rate	2.50%
Junior Credit Facility [Member] \| Key Bank National Association [Member]
Line of Credit Facility, Maximum Borrowing Capacity				$ 50.0
Junior Credit Facility [Member] \| Key Bank National Association [Member] \| Minimum [Member]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage				0.35%
Junior Credit Facility [Member] \| Key Bank National Association [Member] \| Maximum [Member]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage				0.40%
Junior Credit Facility [Member] \| Key Bank National Association [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Line of Credit [Member]
Debt Instrument, Description of Variable Rate Basis				LIBOR plus 4.0%
Junior Credit Facility [Member] \| Key Bank National Association [Member] \| Base Rate [Member] \| Line of Credit [Member]
Debt Instrument, Description of Variable Rate Basis				base rate plus 3.0%
Senior Credit Facility [Member] \| Key Bank National Association [Member]
Debt, Weighted Average Interest Rate					4.66%
Senior Credit Facility [Member] \| Key Bank National Association [Member] \| Minimum [Member]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage			0.20%
Senior Credit Facility [Member] \| Key Bank National Association [Member] \| Maximum [Member]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage			0.25%
Senior Credit Facility [Member] \| Key Bank National Association [Member] \| Line of Credit [Member]
Debt Instrument, Maturity Date			Oct. 04, 2020
Senior Credit Facility [Member] \| Key Bank National Association [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Line of Credit [Member]
Debt Instrument, Description of Variable Rate Basis			LIBOR plus 1.80% to 2.45%
Senior Credit Facility [Member] \| Key Bank National Association [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Line of Credit [Member] \| Minimum [Member]
Debt Instrument, Basis Spread on Variable Rate			1.80%
Senior Credit Facility [Member] \| Key Bank National Association [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Line of Credit [Member] \| Maximum [Member]
Debt Instrument, Basis Spread on Variable Rate			2.45%
Senior Credit Facility [Member] \| Key Bank National Association [Member] \| Base Rate [Member] \| Line of Credit [Member]
Debt Instrument, Description of Variable Rate Basis			base rate plus 0.80% to 1.45%
Senior Credit Facility [Member] \| Key Bank National Association [Member] \| Base Rate [Member] \| Line of Credit [Member] \| Minimum [Member]
Debt Instrument, Basis Spread on Variable Rate			0.80%
Senior Credit Facility [Member] \| Key Bank National Association [Member] \| Base Rate [Member] \| Line of Credit [Member] \| Maximum [Member]
Debt Instrument, Basis Spread on Variable Rate			1.45%
Senior Credit Facility [Member] \| Key Bank National Association [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility, Current Borrowing Capacity			$ 150.0			$ 75.0
Line of Credit Facility, Maximum Borrowing Capacity			$ 250.0			$ 175.0
Term Loan Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 25.0				$ 25.0
Debt Instrument, Description of Variable Rate Basis	base rate plus 2.5%
Debt Instrument, Maturity Date	Mar. 31, 2019