Furniture, Equipment and Leasehold Improvements, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Furniture and office equipment	$ 5,933	$ 5,840
Computer equipment and software	7,330	6,600
Leasehold improvements	11,334	11,071
Furniture, equipment and leasehold improvements, gross	24,597	23,511
Accumulated depreciation and amortization	(16,869)	(14,395)
Furniture, equipment and leasehold improvements, net	$ 7,728	$ 9,116