Statements of Changes in Shareholders' Equity and Redeemable Capital Shares (unaudited) - USD ($) | Total | Retained Earnings [Member] | Redeemable Capital Shares [Member] |
Balance at Dec. 31, 2018 | | | $ 316,828,837 |
Balance, Shares at Dec. 31, 2018 | | | 2,900,000 |
Purchases of Shares | | | $ 112,838,468 |
Purchases of Shares, Shares | | | 1,050,000 |
Redemption of Shares | | | $ (205,804,240) |
Redemption of Shares, Shares | | | (1,900,000) |
Net Increase (Decrease) due to Share Transactions | | | $ (92,965,772) |
Net Increase (Decrease) due to Share Transactions, Shares | | | (850,000) |
Net Comprehensive Income (Loss) | $ (959,668) | $ (959,668) | |
Adjustment of Redeemable Capital Shares to Redemption Value related to Retained Earnings | 959,668 | 959,668 | $ (959,668) |
Adjustment of Redeemable Capital Shares to Redemption Value | | | (687,031) |
Balance at Jun. 30, 2019 | | | $ 222,216,366 |
Balance, Shares at Jun. 30, 2019 | | | 2,050,000 |
Balance at Mar. 31, 2019 | | | $ 219,547,035 |
Balance, Shares at Mar. 31, 2019 | | | 2,050,000 |
Purchases of Shares | | | $ 69,557,423 |
Purchases of Shares, Shares | | | 650,000 |
Redemption of Shares | | | $ (69,735,135) |
Redemption of Shares, Shares | | | (650,000) |
Net Increase (Decrease) due to Share Transactions | | | $ (177,712) |
Net Comprehensive Income (Loss) | (469,408) | (469,408) | |
Adjustment of Redeemable Capital Shares to Redemption Value related to Retained Earnings | 469,408 | 469,408 | (469,408) |
Adjustment of Redeemable Capital Shares to Redemption Value | | | 3,316,451 |
Balance at Jun. 30, 2019 | | | $ 222,216,366 |
Balance, Shares at Jun. 30, 2019 | | | 2,050,000 |
Balance at Dec. 31, 2019 | $ 287,263,846 | | $ 287,263,846 |
Balance, Shares at Dec. 31, 2019 | 2,700,000 | | 2,700,000 |
Purchases of Shares | | | $ 118,900,700 |
Purchases of Shares, Shares | | | 1,150,000 |
Redemption of Shares | | | $ (198,102,363) |
Redemption of Shares, Shares | | | (1,900,000) |
Net Increase (Decrease) due to Share Transactions | | | $ (79,201,663) |
Net Increase (Decrease) due to Share Transactions, Shares | | | (750,000) |
Net Comprehensive Income (Loss) | $ (1,142,215) | (1,142,215) | |
Adjustment of Redeemable Capital Shares to Redemption Value related to Retained Earnings | 1,142,215 | 1,142,215 | $ (1,142,215) |
Adjustment of Redeemable Capital Shares to Redemption Value | | | (273,901) |
Balance at Jun. 30, 2020 | $ 206,646,067 | | $ 206,646,067 |
Balance, Shares at Jun. 30, 2020 | 1,950,000 | | 1,950,000 |
Balance at Mar. 31, 2020 | | | $ 274,974,705 |
Balance, Shares at Mar. 31, 2020 | | | 2,650,000 |
Purchases of Shares | | | $ 41,336,623 |
Purchases of Shares, Shares | | | 400,000 |
Redemption of Shares | | | $ (114,344,354) |
Redemption of Shares, Shares | | | (1,100,000) |
Net Increase (Decrease) due to Share Transactions | | | $ (73,007,731) |
Net Increase (Decrease) due to Share Transactions, Shares | | | (700,000) |
Net Comprehensive Income (Loss) | $ (529,829) | (529,829) | |
Adjustment of Redeemable Capital Shares to Redemption Value related to Retained Earnings | 529,829 | $ 529,829 | $ (529,829) |
Adjustment of Redeemable Capital Shares to Redemption Value | | | 5,208,922 |
Balance at Jun. 30, 2020 | $ 206,646,067 | | $ 206,646,067 |
Balance, Shares at Jun. 30, 2020 | 1,950,000 | | 1,950,000 |