Assets and Liabilities, at Fair Value - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Parenthetical) (Details)

v3.20.4

Assets and Liabilities, at Fair Value - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Parenthetical) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Commemorative coin inventory, held at lower of cost or net realizable value	$ 9	$ 17