Investment in Marketable Securities - Schedule of Net Loss on Marketable Securities Comprising of Realized and Unrealized Gains (Losses) (Details) - USD ($)	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Realized gain (loss) on marketable securities, net	$ 2,746,000	$ (641,000)
Realized loss on marketable securities related to Comstock	(1,870,000)
Unrealized gain (loss) on marketable securities, net	7,372,000	(1,272,000)
Unrealized gain (loss) on marketable securities related to Comstock	3,390,000
Net gain (loss) on marketable securities	$ 11,638,000	$ (1,193,000)