Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating activities:
Net loss	$ (8,558)	$ (7,581)	$ (19,071)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Amortization of intangible assets	2,812	3,374	3,374
Depreciation and amortization of property and equipment	1,734	2,035	3,311
Stock-based compensation	5,673	5,126	4,620
Accretion of premium on marketable securities	0	0	2
Loss (gain) on disposal of property and equipment	(42)	32	24
Impairment of property and equipment	0	0	1,841
Gain on sale of Hungarian subsidiary	0	0	(760)
Loss on disposal and exchange of assets held for sale, net	0	0	87
Change in fair value of assets held for sale	0	0	698
Income tax benefit related to marketable securities	0	(314)	0
Changes in operating assets and liabilities:
Accounts receivable	1,405	(3,459)	1,587
Inventories	167	403	92
Prepaid expenses and other current assets	7	10	(339)
Restricted cash	(841)	0	0
Other assets	52	(16)	(78)
Accounts payable	942	(1,274)	713
Accrued compensation	983	385	(530)
Other accrued liabilities	(593)	(1,062)	555
Deferred revenues	(6,442)	1,908	4,195
Net cash (used in) provided by operating activities	(2,701)	(433)	321
Investing activities:
Purchase of property and equipment	(888)	(1,199)	(302)
Proceeds from disposal of property and equipment	42	18	167
Proceeds from sale of Hungarian subsidiary	0	0	1,500
Proceeds from sale of assets held for sale	0	0	282
Proceeds from sale of marketable securities	0	0	3,000
Change in restricted cash	4	(76)	0
Net cash (used in) provided by investing activities	(842)	(1,257)	4,647
Financing activities:
Proceeds from exercises of stock options	1,034	289	195
Proceeds from issuance of common stock, net of issuance costs	0	0	9
Taxes paid related to net share settlement of equity awards	(1,524)	(1,813)	(815)
Net cash used in financing activities	(490)	(1,524)	(611)
Net increase (decrease) in cash and cash equivalents	(4,033)	(3,214)	4,357
Cash and cash equivalents at the beginning of the year	23,273	26,487	22,130
Cash and cash equivalents at the end of the year	19,240	23,273	26,487
Supplemental cash flow disclosures:
Cash paid for income taxes	5	8	15
Equipment in property and equipment transferred from assets held for sale	$ 0	$ 0	$ (333)