v3.26.1
Investments in Affiliates - Summary of Transactions in, and Earnings from, Investments in Affiliates (Excluding Affiliated Money Market Funds) (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]        
Beginning Value     $ 146,980,895  
Change in Unrealized Appreciation (Depreciation) $ 0 $ (13,938) 0 $ (52,317)
Dividend Income 2,865,141 594,297 4,872,820 1,094,253
Investment Affiliated [Member]        
Investments In And Advances To Affiliates [Line Items]        
Beginning Value     146,980,895  
Ending Value 314,231,596   314,231,596  
Affiliated Investments [Member]        
Investments In And Advances To Affiliates [Line Items]        
Purchases at Cost     318,815,368 72,229,949
Proceeds from Sales     (151,564,667) (31,730,170)
Affiliated Investments [Member] | Invesco Government & Agency Portfolio, Institutional Class [Member]        
Investments In And Advances To Affiliates [Line Items]        
Purchases at Cost 151,537,145 58,973,745 318,815,368 72,229,949
Proceeds from Sales (101,166,675) (15,366,449) (151,564,667) (31,730,170)
Affiliated Investments [Member] | Investment Affiliated [Member]        
Investments In And Advances To Affiliates [Line Items]        
Beginning Value     146,980,895 51,500,959
Ending Value 314,231,596 92,000,738 314,231,596 92,000,738
Dividend Income     4,872,820 1,094,253
Affiliated Investments [Member] | Investment Affiliated [Member] | Invesco Government & Agency Portfolio, Institutional Class [Member]        
Investments In And Advances To Affiliates [Line Items]        
Beginning Value 263,861,126 48,393,442 146,980,895 51,500,959
Ending Value 314,231,596 92,000,738 314,231,596 92,000,738
Dividend Income $ 2,865,141 $ 594,297 $ 4,872,820 $ 1,094,253