Note 2 - Significant Accounting Policies (Details) - Activity in Silver Bullion $ in Thousands	3 Months Ended				9 Months Ended				12 Months Ended
	Sep. 30, 2015 USD ($) oz		Sep. 30, 2014 USD ($) oz		Sep. 30, 2015 USD ($) oz		Sep. 30, 2014 USD ($) oz		Dec. 31, 2014 USD ($) oz
Activity in Silver Bullion [Abstract]
Beginning balance (in Ounces) | oz	325,342,600		322,872,900		329,564,200		320,177,800		320,177,800
Beginning balance, average cost	$ 6,217,768		$ 6,310,696		$ 6,386,750	[1]	$ 6,243,467		$ 6,243,467
Beginning balance, fair value	$ 5,107,880		$ 6,738,358		$ 5,263,140	[1],[2]	$ 6,243,467		6,243,467
Silver bullion contributed (in Ounces) | oz	5,728,500		30,743,400		41,154,000		60,841,000
Silver bullion contributed, average cost	$ 85,929		$ 581,957		$ 664,967		$ 1,184,514
Silver bullion contributed, fair value	$ 85,929		$ 581,957		$ 664,967		$ 1,184,514
Silver bullion distributed (in Ounces) | oz	(12,120,900)		(3,118,600)		(50,950,400)		(29,693,000)
Silver bullion distributed, average cost	$ (231,025)		$ (60,967)		$ (963,268)		$ (580,118)
Silver bullion distributed, fair value	(179,177)		(62,616)		(825,652)		(597,071)
Silver bullion distributed, realized gain (loss)	$ (51,848)		$ 1,649		$ (137,616)		$ 16,953
Silver bullion sold to pay expenses (in Ounces) | oz	(420,600)		(411,300)		(1,238,200)		(1,239,400)
Silver bullion sold to pay expenses, average cost	$ (8,025)		$ (8,041)		$ (23,802)		$ (24,218)
Silver bullion sold to pay expenses, fair value	(6,312)		(8,297)		(19,777)		(24,582)
Silver bullion sold to pay expenses, realized gain (loss)	(1,713)		256	[3]	(4,025)		364	[3]
Net realized gain (loss)	(53,561)		1,905	[3]	(141,641)		17,317	[3]	(78,450)	[4]
Net change in unrealized appreciation/depreciation	$ (288,300)		$ (1,261,329)	[3]	$ (274,578)		$ (833,667)	[3]	$ (1,123,610)	[4]
Ending balance (in Ounces) | oz	318,529,600		350,086,400		318,529,600		350,086,400		329,564,200
Ending balance, average cost	$ 6,064,647		$ 6,823,645		$ 6,064,647		$ 6,823,645		$ 6,386,750	[1]
Ending balance, fair value	4,666,459	[2]	5,989,978		4,666,459	[2]	5,989,978		5,263,140	[1],[2]
Ending balance, realized gain (loss)	$ (53,561)		$ 1,905	[3]	$ (141,641)		$ 17,317	[3]	$ (78,450)	[4]

[1] Previously reported as "Balance Sheets." Please refer to Note 2A.

[2] Cost of investment in silver bullion: $6,064,647 and $6,386,750, respectively.

[3] Previously reported as "Income Statements." Please refer to Note 2A.

[4] Previously reported as "Statements of Changes in Shareholders' Equity (Deficit)." Please refer to Note 2A.