CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating Activities:
Net income (loss)	$ 1,443	$ (766)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	75	159
Amortization of premiums and discounts on investments	37	18
Stock-based compensation	52	376
Changes in assets and liabilities:
Accounts receivable, net	(2,579)	236
Prepaid expenses and other current assets	50	(157)
Operating lease, right-of-use assets	(230)	0
Other long-term assets	72	150
Accounts payable	(11)	(193)
Accrued compensation	(1,028)	(718)
Accrued expense and other current liabilities	37	27
Operating lease liabilities	188	0
Other long-term liabilities	0	(143)
Deferred revenue	180	(338)
Net cash used in operating activities	(1,672)	(1,349)
Investing Activities:
Purchases of property and equipment	(9)	(174)
Purchases of investments	(3,570)	(2,481)
Maturities of investments	9,645	5,694
Net cash (used in) provided by investing activities	6,066	3,039
Effect of exchange rate changes on cash and cash equivalents	8	(65)
Net (decrease) increase in cash and cash equivalents	4,402	1,625
Cash and cash equivalents at beginning of period	25,182	18,050
Cash and cash equivalents at end of period	29,584	19,675
Supplemental schedule of cash flow information:
Income taxes paid	$ 0	$ 47