Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net Income (Loss)	$ 20,565,401	$ (743,983)	$ (62,628,733)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Cost of securities purchased	(172,892,345)	(397,825,651)	(708,832,519)
Proceeds from securities sold and matured	162,999,341	533,077,313	769,759,157
Cost of affiliated investments purchased	(214,960,518)	(369,621,406)	(268,510,956)
Proceeds from affiliated investments sold	203,119,849	332,863,974	286,509,524
Net accretion of discount on United States Treasury Obligations	(308,586)	(2,868,144)	(4,647,103)
Net realized (gain) loss on United States Treasury Obligations and Affiliated Investments	(249)	(22,562)	6,892
Net change in unrealized (gain) loss on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(29,898,418)	(21,097,024)	47,672,410
Change in operating assets and liabilities:
Dividends from affiliates	26,274	2,307	(11,904)
LME Commodity Futures Contracts	(4,999,995)	(28,234,806)	29,029,244
Management fees	31,235	(35,153)	(75,744)
Brokerage commissions and fees	(181)	365	(151)
Net cash provided by (used in) operating activities	(36,318,192)	45,495,230	88,270,117
Cash flows from financing activities:
Distributions paid to shareholders		(2,125,511)	(2,632,618)
Proceeds from purchases of Shares	74,730,960	65,554,435	137,772,825
Redemption of Shares	(38,412,768)	(106,291,536)	(226,042,942)
Increase (decrease) in payable for amount due to custodian		(2,632,618)	2,632,618
Net cash provided by (used in) financing activities	36,318,192	(45,495,230)	(88,270,117)
Supplemental disclosure of cash flow information
Cash paid for interest	$ 1,571	$ 173,324	$ 555,910