CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash Flows from Operating Activities:
Net cash used in operating activities	$ (18,543)	$ (18,649)
Cash Flows from Investing Activities:
Proceeds from sales of and distributions from companies	101,190	69,912
Acquisitions of ownership interest in companies	(9,500)	(3,250)
Advances and loans to companies	(4,954)	(12,098)
Repayment of advances and loans to companies	0	10,652
Purchases of marketable securities	(57,243)	(24,858)
Proceeds from sales and maturities in marketable securities	95,189	4,211
Proceeds from sales of property and equipment	0	1
Net cash provided by investing activities	124,682	44,570
Cash Flows from Financing Activities:
Repayments on credit facility	(68,568)	0
Proceeds from credit facility	0	35,000
Issuance costs of credit facility	0	(2,252)
Repurchase of convertible senior debentures	0	(41,000)
Tax withholdings related to equity-based awards	(210)	(234)
Net cash used in financing activities	(68,778)	(8,486)
Net change in cash, cash equivalents and restricted cash	37,361	17,435
Cash, cash equivalents and restricted cash at beginning of period	8,203	27,087
Cash, cash equivalents and restricted cash at end of period	$ 45,564	$ 44,522