Investment in Marketable Securities - Schedule of Net Loss on Marketable Securities Comprising of Realized and Unrealized Gains (Losses) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Realized loss on marketable securities, net	$ (672,000)	$ (3,000)	$ (934,000)	$ (77,000)
Unrealized gain (loss) on marketable securities, net	4,173,000	(50,000)	4,182,000	(121,000)
Unrealized gain (loss) on marketable securities related to Comstock	(44,000)	(66,000)	51,000	(370,000)
Net gain (loss) on marketable securities	$ 3,457,000	$ (119,000)	$ 3,299,000	$ (568,000)