Investments in Affiliates -Summary of Transactions in, and Earnings from, Investments in Affiliates (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2022		Mar. 31, 2021
Investments In And Advances To Affiliates [Line Items]
Beginning Value	$ 626,458,758
United States Treasury Obligations	(51,835)		$ 14,676
Ending Value	780,011,295
Affiliated Investments [Member]
Investments In And Advances To Affiliates [Line Items]
Beginning Value	626,458,758		245,409,996
Purchases at Cost	408,824,743		313,642,227
Proceeds from Sales	(255,236,806)		(326,791,638)
United States Treasury Obligations	(35,400)		7,080
Ending Value	780,011,295		232,267,665
Dividend Income	112,013		21,552
Affiliated Investments [Member] | Exchange-Traded Fund [Member]
Investments In And Advances To Affiliates [Line Items]
Beginning Value	49,855,000	[1]	49,876,240
United States Treasury Obligations	(35,400)		7,080
Ending Value	49,819,600	[1]	49,883,320
Dividend Income	3,002		7,420
Affiliated Investments [Member] | Money Market Mutual Fund - Invesco Government & Agency Portfolio, Institutional Class [Member]
Investments In And Advances To Affiliates [Line Items]
Beginning Value	576,603,758		195,533,756
Purchases at Cost	408,824,743		313,642,227
Proceeds from Sales	(255,236,806)		(326,791,638)
Ending Value	730,191,695	[1],[2]	182,384,345
Dividend Income	$ 109,011		$ 14,132

[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.

[2] The rate shown is the 7-day SEC standardized yield as of March 31, 2022.