Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating activities:
Net loss	$ (3,706)	$ (10)
Adjustments to reconcile net loss to net cash provided by (used by) operating activities:
Depreciation and amortization	426	495
Provision for doubtful accounts and other adjustments to accounts receivable		12
Provision for excess and obsolete inventory	3	5
Non-cash compensation related to stock options, ESPP and restricted stock	361	576
Loss on disposal of assets	2
Change in operating accounts:
Accounts receivable	2,686	606
Income tax receivable		673
Inventories	9	5
Prepaid expenses and other assets	(208)	62
Accounts payable and accrued liabilities	17	(522)
Deferred revenue	667	(1,167)
Net cash provided by operating activities	257	735
Investing activities:
Capital expenditures	(86)	(21)
Sales (purchases) of short-term investments	2,401	(919)
Net cash provided by (used in) investing activities	2,315	(940)
Financing activities:
Cash received from stock sale for employee stock purchase plan	7	8
Cash received from exercise of stock options		9
Net cash provided by financing activities	7	17
Net increase (decrease) in cash and cash equivalents	2,579	(188)
Cash and cash equivalents, beginning of period	8,819	10,165
Cash and cash equivalents, end of period	11,398	9,977
Supplemental disclosures of cash flow information:
Cash paid for income taxes	$ 21	$ 6