Note 1 - Schedules of Investments (Unaudited) - Investments (Details) $ in Thousands	Jun. 30, 2016 USD ($) oz	Mar. 31, 2016 USD ($) oz	Dec. 31, 2015 USD ($) oz	Jun. 30, 2015 USD ($) oz	Mar. 31, 2015 USD ($) oz	Dec. 31, 2014 USD ($) oz
Silver bullion ounces | oz	333,544,900	332,578,500	317,934,900	325,342,600	321,975,600	329,564,200
Silver bullion cost	$ 6,140,793	$ 6,159,729	$ 5,979,252	$ 6,217,768	$ 6,212,172	$ 6,386,750
Silver bullion fair value	6,123,884		4,393,861
Less Liabilities	(2,361)		(1,917)
Net Assets	$ 6,121,523		$ 4,391,944			$ 5,260,802