Note 2 - Significant Accounting Policies - Activity in Gold Bullion (Details)	3 Months Ended
	Mar. 31, 2024 USD ($) oz		Mar. 31, 2023 USD ($) oz
Beginning balance (Ounce) | oz	12,815,382		14,434,521
Beginning balance, average cost	$ 20,091,705,096		$ 22,205,551,004
Beginning balance, fair value	$ 26,430,443,509	[1]	$ 26,160,403,750
Gold bullion contributed (Ounce) | oz	93,652		354,645
Gold bullion contributed, average cost	$ 190,497,624		$ 683,354,142
Gold bullion contributed, fair value	$ 190,497,624		$ 683,354,142
Gold bullion distributed (Ounce) | oz	(455,023)		(494,033)
Gold bullion distributed, average cost	$ (714,120,151)		$ (762,172,378)
Gold bullion distributed, fair value	(931,768,113)		(915,659,307)
Gold bullion distributed, realized gain (loss)	$ 217,647,962		$ 153,486,929
Gold bullion sold to pay expenses (Ounce) | oz	(7,815)		(8,799)
Gold bullion sold to pay expenses, average cost	$ (12,265,120)		$ (13,561,480)
Gold bullion sold to pay expenses, fair value	(16,055,292)		(16,462,647)
Gold bullion sold to pay expenses, realized gain (loss)	3,790,172		2,901,167
Net realized gain (loss), fair value	221,438,134		156,388,096
Net change in unrealized appreciation/depreciation, fair value	$ 1,665,679,232		$ 2,214,631,754
Ending balance (Ounce) | oz	12,446,196		14,286,334
Ending balance, average cost	$ 19,555,817,449		$ 22,113,171,288
Ending balance, fair value	27,560,235,094	[1]	28,282,655,788
Ending balance, realized gain (loss)	$ 221,438,134		$ 156,388,096

[1] Cost of investment in gold bullion: $19,555,817,449 and $20,091,705,096, respectively.