CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash Flows from Operating Activities:
Net loss	$ (22,262)	$ (59,524)	$ (5,149)
Adjustments to reconcile to net cash used in operating activities:
Depreciation	328	190	74
Amortization of debt discount	1,604	1,472	1,349
Equity (income) loss	(671)	39,599	15,335
Other (income) loss, net	1,682	(217)	(31,657)
Stock-based compensation expense	2,394	1,611	1,935
Changes in assets and liabilities:
Accounts receivable, net	(1,521)	(923)	(369)
Accounts payable, accrued expenses, and other	(215)	43	(1,707)
Net cash used in operating activities	(18,661)	(17,749)	(20,189)
Cash Flows from Investing Activities:
Acquisitions of ownership interests in companies	(52,431)	(70,186)	(59,476)
Proceeds from sales of and distributions from companies	73,965	25,058	82,822
Advances and loans to companies	(27,967)	(15,208)	(10,968)
Repayment of advances and loans to companies	1,741	1,318	4,684
Increase in marketable securities	(21,194)	(29,755)	(55,594)
Decrease in marketable securities	46,315	33,640	55,410
Capital expenditures	(432)	(1,856)	(59)
Other, net	64	0	137
Net cash provided by (used in) investing activities	20,061	(56,989)	16,956
Cash Flows from Financing Activities:
Repurchase of convertible senior debentures	0	0	(441)
Payments Related to Tax Withholding for Share-based Compensation	(460)	0	0
Issuance of Company common stock, net	5	676	1,289
Repurchase of Company common stock	(5,389)	(4,997)	(25,036)
Net cash used in financing activities	(5,844)	(4,321)	(24,188)
Net change in cash, cash equivalents and restricted cash equivalents	(4,444)	(79,059)	(27,421)
Cash, cash equivalents and restricted cash equivalents at beginning of period	32,838	111,897	139,318
Cash, cash equivalents and restricted cash equivalents at end of period	$ 28,394	$ 32,838	$ 111,897