Equity-Based Compensation Expense Included in Interim Condensed Consolidated Statements of Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total equity-based compensation expense	$ 849	$ 1,513
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total equity-based compensation expense	35	58
Research and development, net
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total equity-based compensation expense	391	601
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total equity-based compensation expense	79	302
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total equity-based compensation expense	$ 344	$ 552