Fixed Assets - Major Classifications of Fixed Assets and Related Useful Lives (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 73,025	$ 66,235
Less accumulated depreciation and amortization	(29,880)	(28,759)
Fixed assets, net	43,145	37,476
Land
Property, Plant and Equipment [Line Items]
Fixed assets, gross	5,892	5,892
Building and Improvements
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 25,701	25,516
Building and Improvements | Minimum
Property, Plant and Equipment [Line Items]
Fixed assets, useful life	5 years
Building and Improvements | Maximum
Property, Plant and Equipment [Line Items]
Fixed assets, useful life	40 years
Furniture and Equipment
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 17,084	11,802
Furniture and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Fixed assets, useful life	5 years
Furniture and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Fixed assets, useful life	20 years
Computer Equipment
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 11,003	11,393
Computer Equipment | Minimum
Property, Plant and Equipment [Line Items]
Fixed assets, useful life	3 years
Computer Equipment | Maximum
Property, Plant and Equipment [Line Items]
Fixed assets, useful life	5 years
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 13,345	$ 11,632
Leasehold Improvements | Minimum
Property, Plant and Equipment [Line Items]
Fixed assets, useful life	3 years
Leasehold Improvements | Maximum
Property, Plant and Equipment [Line Items]
Fixed assets, useful life	5 years