Condensed Consolidated Statements of Operations (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Cost of Revenue [Member]
Recognized stock-based compensation expense	$ 582	$ 382	$ 1,114	$ 851
Research and Development [Member]
Recognized stock-based compensation expense	1,931	1,671	4,166	3,538
Sales and Marketing [Member]
Recognized stock-based compensation expense	1,172	947	2,583	1,835
General and Administrative [Member]
Recognized stock-based compensation expense	$ 3,968	$ 2,798	$ 8,254	$ 6,218