v3.26.1
Investments in Affiliates - Summary of Transactions in, and Earnings from, Investments in Affiliates (Detail) - USD ($)
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Investments in and Advances to Affiliates [Line Items]        
Investment Owned, at Fair Value, Ending Balance $ 436,604,450   $ 436,604,450  
Dividend Income 3,482,236 $ 1,781,823 6,023,826 $ 4,785,718
Affiliated Investments [Member] | Money Market Mutual Fund - Invesco Government & Agency Portfolio, Institutional Class [Member]        
Investments in and Advances to Affiliates [Line Items]        
Investment Owned, at Fair Value, Beginning Balance 562,700,245 190,718,083 221,425,729 279,113,690
Purchases at Cost 260,943,157 276,439,893 678,082,276 573,521,267
Proceeds from Sales (387,038,952) (263,783,471) (462,903,555) (649,260,452)
Investment Owned, at Fair Value, Ending Balance 436,604,450 203,374,505 436,604,450 203,374,505
Dividend Income $ 3,482,236 $ 1,781,823 $ 6,023,826 $ 4,785,718