Investments in Affiliates - Summary of Transactions in, and Earnings from, Investments in Affiliates (Excluding Affiliated Money Market Funds) (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2022		Mar. 31, 2021
Investments In And Advances To Affiliates [Line Items]
Beginning Value	$ 2,004,216,762
Change in Unrealized Appreciation (Depreciation)	(172,385)		$ 99,032
Ending Value	3,302,412,035
Affiliated Investments [Member]
Investments In And Advances To Affiliates [Line Items]
Beginning Value	2,004,216,762		891,104,755
Purchases at Cost	2,696,272,106		966,097,731
Proceeds from Sales	(1,397,939,891)		(878,918,579)
Change in Unrealized Appreciation (Depreciation)	(136,942)		25,686
Ending Value	3,302,412,035		978,309,593
Dividend Income	472,527		89,577
Affiliated Investments [Member] | Invesco Government & Agency Portfolio, Institutional Class [Member]
Investments In And Advances To Affiliates [Line Items]
Beginning Value	1,811,356,075		710,155,447
Purchases at Cost	2,696,272,106		966,097,731
Proceeds from Sales	(1,397,939,891)		(878,918,579)
Ending Value	3,109,688,290		797,334,599
Dividend Income	460,914		62,658
Affiliated Investments [Member] | Invesco Treasury Collateral ETF [Member]
Investments In And Advances To Affiliates [Line Items]
Beginning Value	192,860,687	[1]	180,949,308
Change in Unrealized Appreciation (Depreciation)	(136,942)		25,686
Ending Value	192,723,745	[1]	180,974,994
Dividend Income	$ 11,613		$ 26,919

[1] Affiliated issuer. The issuer and/or the Fund is a wholly-owned subsidiary of Invesco Ltd., or is affiliated by having an investment adviser that is under common control of Invesco Ltd. See Note 8.