v3.25.1
Investments in Affiliates - Summary of Transactions in, and Earnings from, Investments in Affiliates (Detail) - USD ($)
 3 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Investments In And Advances To Affiliates [Line Items]    
Beginning Value $ 208,478,795  
Change in Unrealized Appreciation (Depreciation) (23,643) $ (54,165)
Ending Value 181,405,112  
Dividend Income 1,521,904 2,163,257
Affiliated Investments [Member]    
Investments In And Advances To Affiliates [Line Items]    
Beginning Value 155,007,856 162,850,666
Purchases at Cost 68,723,341 85,300,116
Proceeds from Sales (82,283,418) (82,820,946)
Change in Unrealized Appreciation (Depreciation) (33,247) (69,052)
Ending Value 141,414,532 165,260,784
Dividend Income 1,521,904 2,163,257
Affiliated Investments [Member] | Money Market Mutual Fund - Invesco Government and Agency Portfolio - Institutional Class [Member]    
Investments In And Advances To Affiliates [Line Items]    
Beginning Value 100,993,456 108,833,709
Purchases at Cost 68,723,341 85,300,116
Proceeds from Sales (82,283,418) (82,820,946)
Ending Value 87,433,379 111,312,879
Dividend Income 942,170 1,469,443
Affiliated Investments [Member] | Invesco Short Term Treasury ETF [Member]    
Investments In And Advances To Affiliates [Line Items]    
Beginning Value 54,014,400 54,016,957
Change in Unrealized Appreciation (Depreciation) (33,247) (69,052)
Ending Value 53,981,153 53,947,905
Dividend Income $ 579,734 $ 693,814