5. Investments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Loss on sale of investment	$ (1,642)	$ 0	$ (7,232)	$ 0
Net realized and unrealized gain (loss) on investment	6,980	11,347	13,888	(29,750)
Investments - Warrants [Member]
Change in fair value of investment	3,091	2,865	2,394	(4,782)
Investments - Common Stock [Member]
Change in fair value of investment	3,889	8,482	11,494	(24,968)
Loss on sale of investment	$ (1,642)	$ 0	$ (7,232)	$ 0