Derivative Financial Instruments (Details Textual) $ in Millions	Dec. 31, 2018 USD ($)
Interest Rate Cap [Member]
Amount Of Debt Covered By Derivatives	$ 415.2

The total amount of variable debt covered by the derivatives.

No definition available.

Name:	brg_AmountOfDebtCoveredByDerivatives
Namespace Prefix:	brg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant