Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income (loss) including noncontrolling interests in subsidiaries	$ 113,444	$ (17,129)
Adjustments to reconcile net income (loss) including noncontrolling interests in subsidiaries to net cash provided by (used in) operating activities:
Change in fair value of investment, net (Note 6)	(5,474)	(9,899)
Loss (gain) on sale of investment (Note 6)	(8,187)	9,230
Impairment of other investment	0	8,195
Gain on disposal of other investment (Note 6)	0	(2,000)
Depreciation and amortization	4,800	3,227
Amortization of debt discount and issuance costs	2,838	0
Change in fair value of Series A redeemable convertible preferred stock embedded derivative	8,754	(3,258)
Change in fair value of Series A warrant	3,072	(1,260)
Change in fair value of Series B warrants	46,412	0
Non-cash stock compensation	1,662	1,075
Loss on foreign currency exchange	4,905	0
Change in value of trading securities and equity securities - private	(176,173)	(2,241)
Gain on sale of trading securities	(7,352)	0
Gain on sale of prepaid investment and derivative	(2,845)	0
Changes in assets and liabilities:
Accounts receivable	5	32,373
Prepaid expenses and other assets	(2,919)	(220)
Accounts payable and accrued expenses	(2,546)	109
Royalties and contingent legal fees payable	(16)	(20,510)
Net cash used in operating activities	(19,620)	(2,308)
Cash flows from investing activities:
Patent acquisition	(13,780)	(4,420)
Sale of investment at fair value (Note 6)	12,409	6,628
Sale of other investments (Note 6)	0	2,000
Purchases of trading securities	(46,492)	(147,178)
Maturities and sales of trading securities	347,332	75,090
Acquisition of LF Equity Income Fund equity securities	(280,263)	0
Distributions to noncontrolling interests in operating subsidiary	(409)	0
Purchases of property and equipment	(199)	(183)
Net cash provided by (used in) investing activities	18,598	(68,063)
Cash flows from financing activities:
Repurchase of common stock	(3,998)	0
Issuance of Senior Secured Notes, net of lender fee	110,437	0
Senior Secured Notes issuance costs paid to other parties	(496)	0
Dividend on Series A Redeemable Convertible Preferred Stock	(1,382)	0
Issuance of Series A redeemable convertible preferred stock and Series A warrants, net of issuance costs	0	33,842
Issuance of Series B warrants	4,600	0
Proceeds from exercise of stock options	48	79
Net cash provided by financing activities	109,209	33,921
Increase (decrease) in cash and cash equivalents and restricted cash	108,187	(36,450)
Cash and cash equivalents and restricted cash, beginning	92,359	128,809
Cash and cash equivalents and restricted cash, ending	$ 200,546	$ 92,359