Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities
Net loss	$ (2,127)	$ (44,394)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Amortization of patent portfolio	1,062	4,872
Change in fair value of warrant liabilities	(1,031)
Stock-based compensation	299	134
Depreciation expenses	1	1
Realized loss on marketable securities	57	61
Unrealized gain on marketable securities	(29)	(45)
Impairment of goodwill and intangible assets		37,212
Changes in assets and liabilities:
Prepaid expenses and other assets	231	34
Accounts payable and accrued expenses	(124)	(217)
Accrued salaries and benefits	(571)	(64)
Deferred revenue	4,126
Accrued lease liabilities	(90)	(86)
Net cash provided by (used in) operating activities	1,804	(2,492)
Cash flows from investing activities
Purchase of marketable securities	(10,193)	(3,774)
Purchase of property and equipment	(3)
Sale of marketable securities	7,886	6,483
Net cash (used in) provided by investing activities	(2,310)	2,709
Cash flows from financing activities
Cash paid for cancellation of common stocks	(4)
Proceeds from exercise of warrants	760
Redemption of Series I redeemable convertible preferred stock		(935)
Net cash provided by (used in) financing activities	756	(935)
Net increase (decrease) in cash and cash equivalents	250	(718)
Cash and cash equivalents, beginning of period	142	805
Cash and cash equivalents, end of period	392	87
Cash paid for interest and taxes
Non-cash investing and financing activities
Extinguishment of Series H Convertible Preferred Stock in connection with license agreement	31,480
Recognition of deferred revenue in connection with license agreement	$ 414