Financial Instruments with Off-Balance-Sheet Risk and Credit Risk - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Risks And Uncertainties [Abstract]
Liabilities related to right	$ 0	$ 0
Significant cost related to right	$ 0	$ 0	$ 0

Liabilities related to right to charge broker-dealer subsidiaries.

No definition available.

Name:	fbrc_LiabilitiesRelatedToRightToChargeBrokerDealerSubsidiaries
Namespace Prefix:	fbrc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant