Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Revenue	$ 29,886	$ 24,847
Cost of revenue	8,151	7,190
Gross profit	21,735	17,657
Operating expenses:
Research and development expenses	5,609	4,001
Selling, general and administrative expenses	21,270	21,581
Total operating expenses	26,879	25,582
Loss from operations	(5,144)	(7,925)
Other income (expense):
Interest expense	(18)	(237)
Interest income	43	14
Other	(141)	466
Loss before income tax expense	(5,260)	(7,682)
Income tax expense	6	27
Net loss	(5,266)	(7,709)
Basic and diluted net loss per share	$ (0.19)	$ (0.31)
Weighted average shares outstanding-basic and diluted	27,069	24,766
Comprehensive loss:
Unrealized gains (losses) on investments	37	(2)
Foreign currency translation adjustment	(487)	2
Other comprehensive loss	(450)
Net loss	(5,266)	(7,709)
Comprehensive loss	$ (5,716)	$ (7,709)