Components of 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	$ 34,417	$ 34,089
Accumulated amortization and depreciation	(18,414)	(16,993)
Property and equipment, net	16,003	17,096
Computer equipment
Property Plant And Equipment [Line Items]
Property and equipment	12,114	9,739
Furniture and fixtures
Property Plant And Equipment [Line Items]
Property and equipment	1,876	2,176
Developed software
Property Plant And Equipment [Line Items]
Property and equipment	12,378	13,930
Purchased software
Property Plant And Equipment [Line Items]
Property and equipment	2,149	2,124
Leasehold improvements
Property Plant And Equipment [Line Items]
Property and equipment	$ 5,900	$ 6,120