Property and Equipment, net - Property and Equipment, net (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Buildings	$ 1,616	$ 1,602
Data processing equipment	85,698	77,588
Furniture and equipment	8,602	7,540
Leasehold improvements	3,156	2,964
Property and equipment	99,072	89,694
Less-accumulated depreciation and amortization	(68,878)	(61,580)
Depreciable assets, net	30,194	28,114
Land	1,433	1,421
Property and equipment, net	$ 31,627	$ 29,535
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	30 years
Data Processing Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years
Data Processing Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	5 years
Furniture and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years
Furniture and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	20 years
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	5 years
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	10 years