Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net loss	$ (19,228)	$ (21,232)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation	1,970	1,610
Stock-based compensation	14,445	9,455
Capital gain from disposal of fixed assets	(14)	(2)
Changes in assets and liabilities:
Trade receivables	9,181	17,311
Prepaid expenses and other current assets	(838)	(930)
Trade payables	78	(1,668)
Accrued expenses and other short term liabilities	4,167	(502)
Severance pay	41	28
Deferred revenues	1,390	402
Other long term liabilities	(346)	64
Net cash provided by operating activities	10,846	4,536
Cash flows from investing activities:
Increase in short-term investments	(9,473)	(13,250)
Increase in long-term deposits	(209)	(27)
Increase in restricted cash	(43)	(41)
Proceeds on sales of property and equipment	14	2
Purchase of property and equipment	(3,572)	(2,576)
Net cash used in investing activities	(13,283)	(15,892)
Cash flows from financing activities:
Proceeds from employee stock plans, net	7,600	3,803
Net cash provided by financing activities	7,600	3,803
Increase (decrease) in cash and cash equivalents	5,163	(7,553)
Cash and cash equivalents at beginning of period	48,315	49,241
Cash and cash equivalents at end of period	53,478	41,688
Supplemental disclosure of non-cash flow information:
Deferred rent fixed asset additions		37
Cash paid for income taxes	$ 278	$ 133