Noncash Share-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 20,466	$ 27,864	$ 22,665
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$ 33,778
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition	2 years 2 months 10 days
Cost of revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 2,267	3,719	3,469
Selling and Marketing Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	3,824	8,536	6,514
General and Administrative Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	9,040	10,293	8,003
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	5,335	5,316	4,679
Stock compensation in operating expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 18,199	$ 24,145	$ 19,196