Note 2 - Significant Accounting Policies - Activity in Gold Bullion (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) oz		Dec. 31, 2022 USD ($) oz		Dec. 31, 2021 USD ($) oz
Beginning balance (Ounce) | oz	14,434,521		15,784,325		16,881,652
Beginning balance, average cost	$ 22,205,551,004		$ 23,722,912,868		$ 25,014,142,586
Beginning balance, fair value	$ 26,160,403,750	[1]	$ 28,729,048,695		$ 31,924,891,396
Gold bullion contributed (Ounce) | oz	1,012,197		1,587,029		1,010,824
Gold bullion contributed, average cost	$ 1,988,659,596		$ 2,989,014,129		$ 1,853,104,516
Gold bullion contributed, fair value	$ 1,988,659,596		$ 2,989,014,129		$ 1,853,104,516
Gold bullion distributed (Ounce) | oz	(2,596,342)		(2,896,772)		(2,067,597)
Gold bullion distributed, average cost	$ (4,048,057,747)		$ (4,445,139,253)		$ (3,083,787,949)
Gold bullion distributed, fair value	(4,970,554,906)		(5,018,182,038)		(3,649,216,540)
Gold bullion distributed, realized gain (loss)	$ 922,497,159		$ 573,042,785		$ 565,428,591
Gold bullion sold to pay expenses (Ounce) | oz	(34,994)		(40,061)		(40,554)
Gold bullion sold to pay expenses, average cost	$ (54,447,757)		$ (61,236,740)		$ (60,546,285)
Gold bullion sold to pay expenses, fair value	(67,745,940)		(71,964,743)		(73,370,533)
Gold bullion sold to pay expenses, realized gain (loss)	13,298,183		10,728,003		12,824,248
Net realized gain (loss), fair value	935,795,342		583,770,788		578,252,839
Net change in unrealized appreciation/depreciation, fair value	$ 2,383,885,667		$ (1,051,283,081)		$ (1,904,612,983)
Ending balance (Ounce) | oz	12,815,382		14,434,521		15,784,325
Ending balance, average cost	$ 20,091,705,096		$ 22,205,551,004		$ 23,722,912,868
Ending balance, fair value	26,430,443,509	[1]	26,160,403,750	[1]	28,729,048,695
Ending balance, realized gain (loss)	$ 935,795,342		$ 583,770,788		$ 578,252,839

[1] Cost of investment in gold bullion: $20,091,705,096 and $22,205,551,004, respectively.