Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
Balance Sheets
Silver bullion inventory, fair value	$ 10,737,494	$ 10,755,319
Redeemable capital shares, par value	$ 0	$ 0
Redeemable capital shares, issued	314,400,000	359,200,000
Redeemable capital shares, outstanding	314,400,000	359,200,000