Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating activities:
Net loss	$ (3,298)	$ (5,528)
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization of intangible assets	2,531	2,531
Depreciation and amortization of property and equipment	1,365	1,569
Gain on disposal of property and equipment	(35)	(5)
Income tax benefit related to marketable securities	0	(200)
Stock-based compensation	3,861	3,759
Changes in operating assets and liabilities:
Restricted cash, current	(883)	0
Accounts receivable, net	(4,636)	(9,738)
Inventories	(84)	717
Prepaid expenses and other assets, current	(18)	163
Other assets	38	29
Accounts payable	(1,046)	(3,606)
Accrued compensation	(307)	(393)
Other accrued liabilities	60	(523)
Long term lease incentive	(319)	(319)
Deferred revenues	(4,252)	3,955
Net cash used in operating activities	(7,023)	(7,589)
Investing activities:
Purchase of property and equipment	(787)	(288)
Proceeds from disposal of property and equipment	35	5
Decrease (increase) in restricted cash	4	(75)
Net cash used in investing activities	(748)	(358)
Financing activities:
Proceeds from exercises of options	939	235
Taxes paid related to net share settlement of equity awards	(1,523)	(1,812)
Net cash used in financing activities	(584)	(1,577)
Net decrease in cash and cash equivalents	(8,355)	(9,524)
Cash and cash equivalents at the beginning of the period	23,273	26,487
Cash and cash equivalents at the end of the period	$ 14,918	$ 16,963