Regulatory Capital Requirements - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
FBRCM [Member]
Securities Financing Transaction [Line Items]
Net capital	$ 40,869	$ 60,761
Net capital, excess of minimum required capital	38,793	56,994
Minimum net capital required	2,076	$ 3,767
MLV [Member]
Securities Financing Transaction [Line Items]
Net capital	663
Net capital, excess of minimum required capital	413
Minimum net capital required	$ 250