General General (Details) (Southern Trust Mortgage [Member], USD $) In Millions, unless otherwise specified	5 Months Ended
Sep. 30, 2014
Southern Trust Mortgage [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Warehouse participation agreement, maximum lending capacity	$ 17.00

Warehouse Participation Agreement, Maximum Lending Capacity

No definition available.

Name:	mbrg_WarehouseParticipationAgreementMaximumLendingCapacity
Namespace Prefix:	mbrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration