Note 2 - Significant Accounting Policies - Activity in Gold Bullion (Details)	12 Months Ended
	Dec. 31, 2016 USD ($) oz		Dec. 31, 2015 USD ($) oz		Dec. 31, 2014 USD ($) oz
Beginning balance (Ounce) | oz	4,905,568		5,182,164		5,220,493
Beginning balance, average cost	$ 5,910,175,908		$ 6,254,868,124		$ 6,272,422,250
Beginning balance, fair value	$ 5,210,940,144	[1]	$ 6,214,710,412		$ 6,272,422,250
Gold bullion contributed (Ounce) | oz	3,036,655		696,554		466,018
Gold bullion contributed, average cost	$ 3,784,339,342		$ 830,130,993		$ 590,756,513
Gold bullion contributed, fair value	$ 3,784,339,342		$ 830,130,993		$ 590,756,513
Gold bullion distributed (Ounce) | oz	(1,618,237)		(959,873)		(491,071)
Gold bullion distributed, average cost	$ (1,968,318,439)		$ (1,158,780,335)		$ (592,311,684)
Gold bullion distributed, fair value	(1,992,755,088)		(1,071,599,347)		(605,981,738)
Gold bullion distributed, realized gain (loss)	$ 24,436,649		$ (87,180,988)		$ 13,670,054
Gold bullion sold to pay expenses (Ounce) | oz	(15,924)		(13,277)		(13,276)
Gold bullion sold to pay expenses, average cost	$ (19,273,468)		$ (16,042,874)		$ (15,998,955)
Gold bullion sold to pay expenses, fair value	(19,905,623)		(15,431,681)		(16,697,643)
Gold bullion sold to pay expenses, realized gain (loss)	632,155		(611,193)		698,688
Net realized gain (loss), fair value	25,068,804		(87,792,181)		14,368,742
Net change in unrealized appreciation/depreciation, fair value	$ 303,987,270		$ (659,078,052)		$ (40,157,712)
Ending balance (Ounce) | oz	6,308,062		4,905,568		5,182,164
Ending balance, average cost	$ 7,706,923,343		$ 5,910,175,908		$ 6,254,868,124
Ending balance, fair value	7,311,674,849	[1]	5,210,940,144	[1]	6,214,710,412
Ending balance, realized gain (loss)	$ 25,068,804		$ (87,792,181)		$ 14,368,742

[1] Cost of investment in gold bullion: $7,706,923,343 and $5,910,175,908, respectively.