XML 35 R21.htm IDEA: XBRL DOCUMENT v3.19.1
Redeemable Capital Shares - Schedule for Redeemable Capital Shares Activity (Detail) - USD ($)
 3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Temporary Equity Disclosure [Abstract]    
Opening Balance, Shares 2,900,000 2,350,000
Shares Issued, Shares 400,000 2,400,000
Shares Redeemed, Shares (1,250,000) (1,850,000)
Ending Balance, Shares 2,050,000 2,900,000
Opening Balance, Amount $ 316,828,837 $ 271,881,278
Shares Issued, Amount 43,281,045 283,986,452
Shares Redeemed, Amount (136,069,105) (218,903,758)
Adjustment of Redeemable Capital Shares to Redemption Value, Amount (4,493,742) 5,973,995
Ending Balance, Amount $ 219,547,035 $ 342,937,967