Furniture, Equipment and Leasehold Improvements, Net - Furniture, Equipment and Leasehold Improvements, Net (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Furniture, equipment and leasehold improvements, gross	$ 16,936	$ 16,456
Accumulated depreciation and amortization	(9,717)	(8,668)
Furniture, equipment and leasehold improvements, net	7,219	7,788
Furniture and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment and leasehold improvements, gross	4,033	4,058
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment and leasehold improvements, gross	5,663	5,533
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment and leasehold improvements, gross	$ 7,240	$ 6,865