Investment in Marketable Securities - Schedule of Net Loss on Marketable Securities Comprising of Realized and Unrealized Gains (Losses) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Realized gain (loss) on marketable securities, net	$ 1,845,000	$ (1,113,000)	$ 911,000	$ (1,190,000)
Realized loss on marketable securities related to Comstock	(1,578,000)		(1,578,000)
Unrealized gain (loss) on marketable securities, net	501,000	(1,254,000)	4,683,000	(1,375,000)
Unrealized gain (loss) on marketable securities related to Comstock	4,870,000	(26,000)	4,921,000	(396,000)
Net gain (loss) on marketable securities	$ 5,638,000	$ (2,393,000)	$ 8,937,000	$ (2,961,000)