Condensed Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Recognized stock-based compensation expense	$ 7,613	$ 7,105	$ 17,893	$ 18,390
Cost of Revenue [Member]
Recognized stock-based compensation expense	665	534	1,499	1,231
Research and Development [Member]
Recognized stock-based compensation expense	2,346	1,886	5,916	4,926
Sales and Marketing [Member]
Recognized stock-based compensation expense	1,773	1,550	4,068	3,899
General and Administrative [Member]
Recognized stock-based compensation expense	$ 2,829	$ 3,135	$ 6,410	$ 8,334