Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net Loss	$ (15,247)	$ (9,715)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	694	491
Deferred tax benefit	(23)	0
Stock-based compensation	2,659	1,611
Non-cash investment income	(1)	(18)
Non-cash patent write-off	19	0
Non-cash loss on disposal of assets	1	0
Changes in assets and liabilities, net of effects of acquisition:
Accounts receivable	(19)	0
Prepaids and other current assets	(8)	(32)
Other assets	(1)	0
Accounts payable	56	295
Accrued expenses	(34)	(86)
Accrued salaries and payroll related expenses	980	79
Deferred revenue	299	0
Deferred rent	(34)	(36)
Net cash used in operating activities	(10,659)	(7,411)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(400)	(415)
Expenditures for patents and domain names	(177)	(342)
Payment for acquisition of business assets, net of acquired cash	(513)	0
Purchase of restricted cash investment		(100)
Redemption of investments held-to-maturity	10,509	15,000
Purchase of investments held-to-maturity	(12,249)	(9,989)
Net cash provided by (used in) investing activities	(2,830)	4,154
CASH FLOWS FROM FINANCING ACTIVITIES
Net proceeds from the sale of common stock from private placement offering	5,177	0
Net proceeds from the sale of common stock from underwritten public offering	10,621	0
Proceeds from exercise of warrants	280	0
Payment of withholding tax on net exercise of stock-based awards	0	(45)
Net cash (used in) provided by financing activities	16,078	(45)
Effects of currency translation on cash and cash equivalents	(6)	0
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	2,583	(3,302)
CASH AND CASH EQUIVALENTS — Beginning of year	2,501	5,803
CASH AND CASH EQUIVALENTS — End of year	5,084	2,501
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Interest	0	0
Taxes	1	1
SUPPLEMENTAL DISCLOSURE OF NON-CASH ACTIVITIES
Issuance of common stock in settlement of liability	110	0
Issuance of common stock in the acquisition of business assets	545	0
Property and equipment included in accounts payable	191	0
Patents included in accounts payable	$ 117	$ 0