Equity-Based Compensation Expense Included in Interim Condensed Consolidated Statements of Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	$ 1,513	$ 1,318
Cost of revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	58	69
Research and development, net
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	601	446
Sales and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	302	296
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total equity-based compensation expense	$ 552	$ 507