Note 2 - Significant Accounting Policies - Activity in Gold Bullion (Details)	3 Months Ended						6 Months Ended
	Jun. 30, 2022 USD ($) oz		Mar. 31, 2022 USD ($) oz		Jun. 30, 2021 USD ($) oz	Mar. 31, 2021 USD ($) oz	Jun. 30, 2022 USD ($) oz		Jun. 30, 2021 USD ($) oz
Beginning balance (Ounce) | oz	16,608,310		15,784,325		16,202,345	16,881,652	15,784,325		16,881,652
Beginning balance, average cost	$ 25,367,951,331		$ 23,722,912,868		$ 24,106,918,759	$ 25,014,142,586	$ 23,722,912,868		$ 25,014,142,586
Beginning balance, fair value	$ 32,255,828,173		28,729,048,695	[1]	$ 27,398,975,237	31,924,891,396	$ 28,729,048,695	[1]	$ 31,924,891,396
Gold bullion contributed (Ounce) | oz	413,312				330,473		1,429,491		620,692
Gold bullion contributed, average cost	$ 782,395,238				$ 614,040,347		$ 2,716,902,584		$ 1,147,897,249
Gold bullion contributed, fair value	$ 782,395,238				$ 614,040,347		$ 2,716,902,584		$ 1,147,897,249
Gold bullion distributed (Ounce) | oz	(608,940)				(291,980)		(791,486)		(1,251,119)
Gold bullion distributed, average cost	$ (934,514,898)				$ (434,459,047)		$ (1,209,438,348)		$ (1,860,113,808)
Gold bullion distributed, fair value	(1,127,722,686)				(514,385,668)		(1,461,644,030)		(2,194,412,656)
Gold bullion distributed, realized gain (loss)	$ 193,207,788				$ 79,926,621		$ 252,205,682		$ 334,298,848
Gold bullion sold to pay expenses (Ounce) | oz	(10,618)				(9,980)		(20,266)		(20,367)
Gold bullion sold to pay expenses, average cost	$ (16,267,696)				$ (14,867,311)		$ (30,813,129)		$ (30,293,279)
Gold bullion sold to pay expenses, fair value	(19,974,426)				(18,028,234)		(37,736,285)		(37,218,922)
Gold bullion sold to pay expenses, realized gain (loss)	3,706,730				3,160,923		6,923,156		6,925,643
Net realized gain (loss), fair value	196,914,518		62,214,320		83,087,544	258,136,947	259,128,838		341,224,491
Net change in unrealized appreciation/depreciation, fair value	$ (2,284,892,586)		$ 1,881,741,015		$ 1,053,747,875	$ (3,618,692,332)	$ (403,151,571)		$ (2,564,944,457)
Ending balance (Ounce) | oz	16,402,064		16,608,310		16,230,858	16,202,345	16,402,064		16,230,858
Ending balance, average cost	$ 25,199,563,975		$ 25,367,951,331		$ 24,271,632,748	$ 24,106,918,759	$ 25,199,563,975		$ 24,271,632,748
Ending balance, fair value	$ 29,802,548,231	[1]	$ 32,255,828,173		$ 28,617,437,101	$ 27,398,975,237	$ 29,802,548,231	[1]	$ 28,617,437,101

[1] Cost of investment in gold bullion: $25,199,563,975 and $23,722,912,868, respectively.