Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash Flows from Operating Activities:
Net cash used in operating activities	$ (5,775)	$ (12,181)
Cash Flows from Investing Activities:
Proceeds from sales of and distributions from ownership interests	1,024	99,324
Acquisitions of ownership interests	(5,010)	(6,000)
Advances and loans to ownership interests	(1,638)	(4,618)
Purchases of marketable securities		(57,243)
Proceeds from sales and maturities in marketable securities		70,189
Net cash (used in) provided by investing activities	(5,624)	101,652
Cash Flows from Financing Activities:
Repayments on credit facility		(24,024)
Tax withholdings related to equity-based awards	(22)	(180)
Net cash used in financing activities	(22)	(24,204)
Net change in cash, cash equivalents and restricted cash	(11,421)	65,267
Cash, cash equivalents and restricted cash at beginning of period	25,053	8,203
Cash, cash equivalents and restricted cash at end of period	$ 13,632	$ 73,470