Condensed Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Flows from Operating Activities:
Net income (loss)	$ (8,143,415)	$ (74,935,061)	$ 28,605,741
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
(Increase) decrease in short-term investments	295,216	73,468,910	(73,764,126)
Unrealized (gain) loss on open futures contracts	(17,876,577)	23,145,242	(5,699,448)
(Increase) decrease in receivable from Sponsor	(16,330)	34,387	62,127
(Increase) decrease in dividends receivable	(15,534)	(11,339)	0
(Increase) decrease in interest receivable	4,320	10,558	(13,743)
(Increase) decrease in prepaid insurance	20,989	(35,750)	(820)
(Increase) decrease in ETF transaction fees receivable	(350)	700	(350)
Increase (decrease) in payable due to Broker	429,967	(442,429)	442,429
Increase (decrease) in management fees payable	(226,413)	40,440	(117,011)
Increase (decrease) in professional fees payable	(17,963)	20,887	(73,549)
Increase (decrease) in brokerage commissions payable	(9,500)	0	(10,710)
Increase (decrease) in directors' fees and payable	(7,540)	8,206	(128)
Net cash provided by (used in) operating activities	(25,563,130)	21,304,751	(50,569,588)
Cash Flows from Financing Activities:
Addition of shares	7,153,775	194,196,690	60,366,979
Redemption of shares	(274,802,204)	(160,352,516)	(223,268,046)
Net cash provided by (used in) financing activities	(267,648,429)	33,844,174	(162,901,067)
Net Increase (Decrease) in Cash and Cash Equivalents	(293,211,559)	55,148,925	(213,470,655)
Total Cash, Cash Equivalents and Equity in Trading Accounts, beginning of period	490,625,457	435,476,532	648,947,187
Total Cash, Cash Equivalents and Equity in Trading Accounts, end of period	197,413,898	490,625,457	435,476,532
United States Commodity Index Fund
Cash Flows from Operating Activities:
Net income (loss)	(8,413,932)	(71,770,971)	26,490,920
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
(Increase) decrease in short-term investments	0	71,291,769	(71,291,769)
Unrealized (gain) loss on open futures contracts	(16,626,852)	21,360,954	(4,817,510)
(Increase) decrease in dividends receivable	(15,527)	(9,983)	0
(Increase) decrease in interest receivable	4,224	9,374	(12,337)
(Increase) decrease in prepaid insurance	21,039	(35,991)	(412)
(Increase) decrease in ETF transaction fees receivable	(350)	350
Increase (decrease) in management fees payable	(224,947)	41,641	(119,158)
Increase (decrease) in professional fees payable	(32,474)	64,879	(20,651)
Increase (decrease) in brokerage commissions payable	(9,500)	0	(10,710)
Increase (decrease) in directors' fees and payable	(7,506)	8,176	(256)
Net cash provided by (used in) operating activities	(25,305,825)	20,960,198	(49,781,883)
Cash Flows from Financing Activities:
Addition of shares	0	183,685,233	49,804,005
Redemption of shares	(262,889,394)	(152,234,093)	(215,240,793)
Net cash provided by (used in) financing activities	(262,889,394)	31,451,140	(165,436,788)
Net Increase (Decrease) in Cash and Cash Equivalents	(288,195,219)	52,411,338	(215,218,671)
Total Cash, Cash Equivalents and Equity in Trading Accounts, beginning of period	478,509,213	426,097,875	641,316,546
Total Cash, Cash Equivalents and Equity in Trading Accounts, end of period	190,313,994	478,509,213	426,097,875
United States Copper Index Fund
Cash Flows from Operating Activities:
Net income (loss)	270,517	(2,992,568)	2,264,593
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
(Increase) decrease in short-term investments	295,216	1,880,591	(2,175,807)
Unrealized (gain) loss on open futures contracts	(1,249,725)	1,785,413	(793,363)
(Increase) decrease in receivable from Sponsor	(16,330)	(11,146)	35,487
(Increase) decrease in dividends receivable	(7)	(1,356)	0
(Increase) decrease in interest receivable	96	915	(1,137)
(Increase) decrease in prepaid insurance	(50)	19	(203)
(Increase) decrease in ETF transaction fees receivable	0	350	(350)
Increase (decrease) in payable due to Broker	429,967	(442,429)	442,429
Increase (decrease) in management fees payable	(1,466)	831	2,244
Increase (decrease) in professional fees payable	14,511	885	(28,380)
Increase (decrease) in directors' fees and payable	(34)	69	121
Net cash provided by (used in) operating activities	(257,305)	221,574	(254,366)
Cash Flows from Financing Activities:
Addition of shares	7,152,775	10,511,457	10,562,974
Redemption of shares	(11,912,810)	(6,538,962)	(8,027,253)
Net cash provided by (used in) financing activities	(4,760,035)	3,972,495	2,535,721
Net Increase (Decrease) in Cash and Cash Equivalents	(5,017,340)	4,194,069	2,281,355
Total Cash, Cash Equivalents and Equity in Trading Accounts, beginning of period	12,116,244	7,922,175	5,640,820
Total Cash, Cash Equivalents and Equity in Trading Accounts, end of period	7,098,904	12,116,244	$ 7,922,175
USCF Crescent Crypto Index Fund
Cash Flows from Operating Activities:
Net income (loss)	0
Cash Flows from Financing Activities:
Addition of shares	1,000
Redemption of shares	0
Net cash provided by (used in) financing activities	1,000
Net Increase (Decrease) in Cash and Cash Equivalents	1,000
Total Cash, Cash Equivalents and Equity in Trading Accounts, beginning of period	0
Total Cash, Cash Equivalents and Equity in Trading Accounts, end of period	$ 1,000	$ 0