Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities
Net loss	$ (919)	$ (49)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Amortization of patent portfolio	338	531
Change in fair value of warrant liabilities	122	(1,542)
Stock-based compensation	4	131
Depreciation expenses	1
Realized loss on marketable securities	93	66
Unrealized gain on marketable securities	(72)	(12)
Changes in assets and liabilities:
Prepaid expenses and other assets	(10)	38
Accounts payable and accrued expenses	52	(29)
Accrued salaries and benefits	(107)	(534)
Deferred revenue	(307)	(71)
Accrued lease liabilities	(40)	(45)
Net cash used in operating activities	(845)	(1,516)
Cash flows from investing activities
Purchase of marketable securities	(4,121)	(3,456)
Purchase of property and equipment		(2)
Sale of marketable securities	5,042	5,326
Net cash provided by investing activities	921	1,868
Net increase in cash and cash equivalents	76	352
Cash and cash equivalents, beginning of period	134	142
Cash and cash equivalents, end of period	210	494
Cash paid for interest and taxes	$ 1,712