Investment in Marketable Securities - Schedule of Net Loss on Marketable Securities Comprising of Realized and Unrealized Gains (Losses) (Details) - USD ($)	3 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Realized loss on marketable securities, net	$ (262,000)	$ (74,000)
Unrealized gain (loss) on marketable securities, net	9,000	(71,000)
Unrealized gain (loss) on marketable securities related to Comstock	95,000	(304,000)
Net loss on marketable securities	$ (158,000)	$ (449,000)