Property and Equipment (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 29,748 [1] $ 28,614 [1]
Less: accumulated depreciation and amortization (24,318) [1] (23,174) [1]
Property and equipment, net 5,430 [1] 5,440 [1]
Computer and Other Related Equipment    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross 18,662 [1] 17,794 [1]
Purchased and Internally Developed Software    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross 7,836 [1] 7,672 [1]
Furniture and Fixtures    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross 1,416 [1] 1,319 [1]
Leasehold Improvements    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 1,834 [1] $ 1,829 [1]
[1] Includes the original cost and accumulated depreciation of fully-depreciated fixed assets which were $17.4 million and $18.9 million at December 31, 2013 and 2014, respectively.