CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues, net	$ 20,333	$ 27,188
Cost of revenues	8,324	9,190
Gross profit	12,009	17,998
Operating expenses
Sales and marketing	6,676	9,107
Research and development	7,138	8,009
General and administrative	4,177	4,969
Total operating expenses	17,991	22,085
Loss from operations	(5,982)	(4,087)
Interest expense, net	(37)	(18)
Other income, net	299	33
Loss before provision for income taxes	(5,720)	(4,072)
Provision for income taxes	(406)	(341)
Net loss	(6,126)	(4,413)
Foreign currency translation adjustments	219	425
Comprehensive loss	$ (5,907)	$ (3,988)
Net loss per share available to common stockholders, basic and diluted	$ (0.16)	$ (0.12)
Weighted-average shares used to compute net loss per share available to common stockholders, basic and diluted	39,081	37,767
Amortization of intangible assets is allocated as follows (Note 3):
Amortization of intangible assets	$ 730	$ 826
Cost of Revenues [Member]
Stock-based compensation expense is allocated as follows (Note 7):
Allocation of stock-based compensation	311	421
Amortization of intangible assets is allocated as follows (Note 3):
Amortization of intangible assets	247	271
Sales and Marketing [Member]
Stock-based compensation expense is allocated as follows (Note 7):
Allocation of stock-based compensation	212	499
Amortization of intangible assets is allocated as follows (Note 3):
Amortization of intangible assets	223	248
Research and Development [Member]
Stock-based compensation expense is allocated as follows (Note 7):
Allocation of stock-based compensation	996	2,022
Amortization of intangible assets is allocated as follows (Note 3):
Amortization of intangible assets	247	271
General and Administrative [Member]
Stock-based compensation expense is allocated as follows (Note 7):
Allocation of stock-based compensation	323	880
Amortization of intangible assets is allocated as follows (Note 3):
Amortization of intangible assets	$ 13	$ 36