Investments in Affiliates - Summary of Transactions in, and Earnings from, Investments in Affiliates (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Investments in and Advances to Affiliates [Line Items]
Beginning Value			$ 710,772,102
Change in Unrealized Appreciation (Depreciation)	$ 54,344	$ 16,667	(256,614)	$ 82,122
Ending Value	700,902,895		700,902,895
Dividend Income	5,987,840	6,165,721	10,877,082	11,855,336
Investment, Affiliated Issuer [Member]
Investments in and Advances to Affiliates [Line Items]
Beginning Value			367,815,458
Ending Value	407,362,216		407,362,216
Affiliated Investments [Member]
Investments in and Advances to Affiliates [Line Items]
Purchases at Cost	311,928,567	495,609,923	516,869,556	1,146,372,409
Proceeds from Sales	(366,703,889)	(540,737,802)	(477,169,734)	(1,175,184,960)
Change in Unrealized Appreciation (Depreciation)		(68,028)	(153,064)	126,001
Affiliated Investments [Member] | Investment, Affiliated Issuer [Member]
Investments in and Advances to Affiliates [Line Items]
Beginning Value	462,137,538	534,071,959	367,815,458	517,562,602
Ending Value	407,362,216	488,876,052	407,362,216	488,876,052
Dividend Income	5,987,840	6,165,721	10,877,082	11,855,336
Affiliated Investments [Member] | Invesco Government & Agency Portfolio, Institutional Class [Member]
Investments in and Advances to Affiliates [Line Items]
Purchases at Cost	311,928,567	495,609,923	516,869,556	1,115,897,222
Proceeds from Sales	(366,703,889)	(540,737,802)	(477,169,734)	(1,175,184,960)
Affiliated Investments [Member] | Invesco Government & Agency Portfolio, Institutional Class [Member] | Investment, Affiliated Issuer [Member]
Investments in and Advances to Affiliates [Line Items]
Beginning Value	342,555,653	414,422,045	248,080,509	428,581,904
Ending Value	287,780,331	369,294,166	287,780,331	369,294,166
Dividend Income	4,498,934	4,854,322	7,850,256	9,580,656
Affiliated Investments [Member] | Invesco Short Term Treasury ETF [Member]
Investments in and Advances to Affiliates [Line Items]
Purchases at Cost				30,475,187
Change in Unrealized Appreciation (Depreciation)		(68,028)	(153,064)	126,001
Affiliated Investments [Member] | Invesco Short Term Treasury ETF [Member] | Investment, Affiliated Issuer [Member]
Investments in and Advances to Affiliates [Line Items]
Beginning Value	119,581,885	119,649,914	119,734,949	88,980,698
Ending Value	119,581,885	119,581,886	119,581,885	119,581,886
Dividend Income	$ 1,488,906	$ 1,311,399	$ 3,026,826	$ 2,274,680