Furniture, Equipment, Software and Leasehold Improvements - Furniture, Equipment, Software and Leasehold Improvements Summarized by Major Classification (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Furniture, equipment, software and leasehold improvements	$ 34,301	$ 35,419
Less: Accumulated depreciation and amortization	(19,230)	(20,031)
Furniture, equipment, software, and leasehold improvements, net of accumulated depreciation and amortization	15,071	15,388
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, software and leasehold improvements	16,250	17,340
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, software and leasehold improvements	11,206	10,776
Software [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, software and leasehold improvements	$ 6,845	$ 7,303