Condensed Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash Flows from Operating Activities:
Net income (loss)	$ 41,946,702	$ (32,807,530)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Change in unrealized (gain) loss on open commodity futures contracts	9,199,829	(4,607,389)
(Increase) decrease in receivable from Sponsor	58,202	27,859
(Increase) decrease in dividends receivable	(6,221)	23,283
(Increase) decrease in interest receivable	(3)	125
(Increase) decrease in prepaid insurance	(25,935)	9,282
(Increase) decrease in prepaid registration fees	(76,437)	0
(Increase) decrease in ETF transaction fees receivable	(350)	350
Increase (decrease) in payable due to Broker	(1,428,240)	(429,967)
Increase (decrease) in Management fees payable	196,319	(59,086)
Increase (decrease) in professional fees payable	(68,611)	(302,815)
Increase (decrease) in brokerage commissions payable	0	(29,850)
Increase (decrease) in directors' fees payable	4,456	(9,852)
Net cash provided by (used in) operating activities	49,799,711	(38,185,590)
Cash Flows from Financing Activities:
Addition of shares	430,325,884	48,892,034
Redemption of shares	(152,420,876)	(79,660,461)
Net cash provided by (used in) financing activities	277,905,008	(30,768,427)
Net Increase (Decrease) in Cash and Cash Equivalents	327,704,719	(68,954,017)
Total Cash, Cash Equivalents and Equity in Trading Accounts, beginning of period	166,206,573	197,413,898
Total Cash, Cash Equivalents and Equity in Trading Accounts, end of period	493,911,292	128,459,881
United States Commodity Index Fund
Cash Flows from Operating Activities:
Net income (loss)	39,939,638	(35,439,060)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Change in unrealized (gain) loss on open commodity futures contracts	1,326,932	(3,342,751)
(Increase) decrease in dividends receivable	(2,165)	22,713
(Increase) decrease in interest receivable	(6)	0
(Increase) decrease in prepaid insurance	(10,323)	9,489
(Increase) decrease in prepaid registration fees	(16,596)	0
(Increase) decrease in ETF transaction fees receivable	0	350
Increase (decrease) in Management fees payable	80,042	(70,365)
Increase (decrease) in professional fees payable	(153,775)	(278,961)
Increase (decrease) in brokerage commissions payable	0	(29,850)
Increase (decrease) in directors' fees payable	2,725	(9,990)
Net cash provided by (used in) operating activities	41,166,472	(39,138,425)
Cash Flows from Financing Activities:
Addition of shares	109,014,826	18,654,333
Redemption of shares	(24,237,078)	(67,926,335)
Net cash provided by (used in) financing activities	84,777,748	(49,272,002)
Net Increase (Decrease) in Cash and Cash Equivalents	125,944,220	(88,410,427)
Total Cash, Cash Equivalents and Equity in Trading Accounts, beginning of period	103,873,008	190,313,994
Total Cash, Cash Equivalents and Equity in Trading Accounts, end of period	229,817,228	101,903,567
United States Copper Index Fund
Cash Flows from Operating Activities:
Net income (loss)	2,007,064	2,631,530
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Change in unrealized (gain) loss on open commodity futures contracts	7,872,897	(1,264,638)
(Increase) decrease in receivable from Sponsor	58,202	27,859
(Increase) decrease in dividends receivable	(4,056)	570
(Increase) decrease in interest receivable	3	125
(Increase) decrease in prepaid insurance	(15,612)	(207)
(Increase) decrease in prepaid registration fees	(59,841)
(Increase) decrease in ETF transaction fees receivable	(350)
Increase (decrease) in payable due to Broker	(1,428,240)	(429,967)
Increase (decrease) in Management fees payable	116,277	11,279
Increase (decrease) in professional fees payable	85,164	(23,854)
Increase (decrease) in directors' fees payable	1,731	138
Net cash provided by (used in) operating activities	8,633,239	952,835
Cash Flows from Financing Activities:
Addition of shares	321,311,058	30,237,701
Redemption of shares	(128,183,798)	(11,733,126)
Net cash provided by (used in) financing activities	193,127,260	18,504,575
Net Increase (Decrease) in Cash and Cash Equivalents	201,760,499	19,457,410
Total Cash, Cash Equivalents and Equity in Trading Accounts, beginning of period	62,333,565	7,098,904
Total Cash, Cash Equivalents and Equity in Trading Accounts, end of period	264,094,064	26,556,314
USCF Crescent Crypto Index Fund
Cash Flows from Operating Activities:
Net income (loss)	0	0
Cash Flows from Financing Activities:
Addition of shares	0	0
Redemption of shares	0	(1,000)
Net cash provided by (used in) financing activities	0	(1,000)
Net Increase (Decrease) in Cash and Cash Equivalents	0	(1,000)
Total Cash, Cash Equivalents and Equity in Trading Accounts, beginning of period	0	1,000
Total Cash, Cash Equivalents and Equity in Trading Accounts, end of period	0	0
United States Commodity Index Funds Trust
Cash Flows from Operating Activities:
Net income (loss)	$ 41,946,702	$ (32,807,530)