Statements of Changes in Shareholders' Equity and Redeemable Capital Shares (unaudited) - USD ($) | Total | Retained Earnings [Member] | Redeemable Capital Shares [Member] |
Balance at Dec. 31, 2019 | | | $ 287,263,846 |
Balance, Shares at Dec. 31, 2019 | | | 2,700,000 |
Purchases of Shares | | | $ 318,210,622 |
Purchases of Shares, Shares | | | 2,950,000 |
Redemption of Shares | | | $ (270,204,291) |
Redemption of Shares, Shares | | | (2,550,000) |
Net Increase (Decrease) due to Share Transactions | | | $ 48,006,331 |
Net Increase (Decrease) due to Share Transactions, Shares | | | 400,000 |
Net Comprehensive Income (Loss) | $ (1,865,025) | $ (1,865,025) | |
Adjustment of Redeemable Capital Shares to Redemption Value related to Retained Earnings | 1,865,025 | 1,865,025 | $ (1,865,025) |
Adjustment of Redeemable Capital Shares to Redemption Value | | | 8,811,457 |
Balance at Sep. 30, 2020 | | | $ 342,216,609 |
Balance, Shares at Sep. 30, 2020 | | | 3,100,000 |
Balance at Jun. 30, 2020 | | | $ 206,646,067 |
Balance, Shares at Jun. 30, 2020 | | | 1,950,000 |
Purchases of Shares | | | $ 199,309,922 |
Purchases of Shares, Shares | | | 1,800,000 |
Redemption of Shares | | | $ (72,101,928) |
Redemption of Shares, Shares | | | (650,000) |
Net Increase (Decrease) due to Share Transactions | | | $ 127,207,994 |
Net Increase (Decrease) due to Share Transactions, Shares | | | 1,150,000 |
Net Comprehensive Income (Loss) | (722,810) | (722,810) | |
Adjustment of Redeemable Capital Shares to Redemption Value related to Retained Earnings | 722,810 | 722,810 | $ (722,810) |
Adjustment of Redeemable Capital Shares to Redemption Value | | | 9,085,358 |
Balance at Sep. 30, 2020 | | | $ 342,216,609 |
Balance, Shares at Sep. 30, 2020 | | | 3,100,000 |
Balance at Dec. 31, 2020 | $ 327,516,510 | | $ 327,516,510 |
Balance, Shares at Dec. 31, 2020 | 2,850,000 | | 2,850,000 |
Purchases of Shares | | | $ 157,363,731 |
Purchases of Shares, Shares | | | 1,400,000 |
Redemption of Shares | | | $ (173,927,554) |
Redemption of Shares, Shares | | | (1,550,000) |
Net Increase (Decrease) due to Share Transactions | | | $ (16,563,823) |
Net Increase (Decrease) due to Share Transactions, Shares | | | (150,000) |
Net Comprehensive Income (Loss) | $ (2,282,087) | (2,282,087) | |
Adjustment of Redeemable Capital Shares to Redemption Value related to Retained Earnings | 2,282,087 | 2,282,087 | $ (2,282,087) |
Adjustment of Redeemable Capital Shares to Redemption Value | | | (16,981,948) |
Balance at Sep. 30, 2021 | $ 291,688,652 | | $ 291,688,652 |
Balance, Shares at Sep. 30, 2021 | 2,700,000 | | 2,700,000 |
Balance at Jun. 30, 2021 | | | $ 293,727,749 |
Balance, Shares at Jun. 30, 2021 | | | 2,650,000 |
Purchases of Shares | | | $ 43,901,280 |
Purchases of Shares, Shares | | | 400,000 |
Redemption of Shares | | | $ (38,448,899) |
Redemption of Shares, Shares | | | (350,000) |
Net Increase (Decrease) due to Share Transactions | | | $ 5,452,381 |
Net Increase (Decrease) due to Share Transactions, Shares | | | 50,000 |
Net Comprehensive Income (Loss) | $ (772,928) | (772,928) | |
Adjustment of Redeemable Capital Shares to Redemption Value related to Retained Earnings | 772,928 | $ 772,928 | $ (772,928) |
Adjustment of Redeemable Capital Shares to Redemption Value | | | (6,718,550) |
Balance at Sep. 30, 2021 | $ 291,688,652 | | $ 291,688,652 |
Balance, Shares at Sep. 30, 2021 | 2,700,000 | | 2,700,000 |