Financial Highlights Per Share Performance - Summary of per share data (Detail) - $ / shares	3 Months Ended		6 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021
Per Share Data:
Net asset value, beginning of period	$ 4.80	$ 13.86	$ 4.61	$ 13.03
Net increase (decrease) in net assets from investment operations
Net investment loss	(0.04)	(0.11)	(0.07)	(0.20)
Net realized and unrealized gain (loss)	1.47	(0.66)	1.69	0.26
Net increase (decrease) in net assets resulting from operations	1.43	(0.77)	1.62	0.06
Net asset value, end of period	$ 6.23	$ 13.09	$ 6.23	$ 13.09
Total return	29.79%	(5.56%)	35.14%	0.46%
Ratios to average net assets:
Net investment loss	(2.50%)	(2.50%)	(2.50%)	(2.50%)
Expenses	(2.50%)	(2.50%)	(2.50%)	(2.50%)