Note 2 - Significant Accounting Policies - Activity in Gold Bullion (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) oz		Dec. 31, 2021 USD ($) oz		Dec. 31, 2020 USD ($) oz
Beginning balance (Ounce) | oz	15,784,325		16,881,652		11,577,252
Beginning balance, average cost	$ 23,722,912,868		$ 25,014,142,586		$ 15,094,673,874
Beginning balance, fair value	$ 28,729,048,695	[1]	$ 31,924,891,396		$ 17,632,155,037
Gold bullion contributed (Ounce) | oz	1,587,029		1,010,824		6,866,938
Gold bullion contributed, average cost	$ 2,989,014,129		$ 1,853,104,516		$ 12,103,493,289
Gold bullion contributed, fair value	$ 2,989,014,129		$ 1,853,104,516		$ 12,103,493,289
Gold bullion distributed (Ounce) | oz	(2,896,772)		(2,067,597)		(1,527,240)
Gold bullion distributed, average cost	$ (4,445,139,253)		$ (3,083,787,949)		$ (2,134,454,305)
Gold bullion distributed, fair value	(5,018,182,038)		(3,649,216,540)		(2,617,761,048)
Gold bullion distributed, realized gain (loss)	$ 573,042,785		$ 565,428,591		$ 483,306,743
Gold bullion sold to pay expenses (Ounce) | oz	(40,061)		(40,554)		(35,298)
Gold bullion sold to pay expenses, average cost	$ (61,236,740)		$ (60,546,285)		$ (49,570,272)
Gold bullion sold to pay expenses, fair value	(71,964,743)		(73,370,533)		(62,451,444)
Gold bullion sold to pay expenses, realized gain (loss)	10,728,003		12,824,248		12,881,172
Net realized gain (loss), fair value	583,770,788		578,252,839		496,187,915
Net change in unrealized appreciation/depreciation, fair value	$ (1,051,283,081)		$ (1,904,612,983)		$ 4,373,267,647
Ending balance (Ounce) | oz	14,434,521		15,784,325		16,881,652
Ending balance, average cost	$ 22,205,551,004		$ 23,722,912,868		$ 25,014,142,586
Ending balance, fair value	$ 26,160,403,750	[1]	$ 28,729,048,695	[1]	$ 31,924,891,396

[1] Cost of investment in gold bullion: $22,205,551,004 and $23,722,912,868, respectively.