Condensed Schedule of Investments	Mar. 31, 2019 USD ($) Contract
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | Foreign Contracts [Member]
Notional Amount	$ 161,033,386
Number of Contracts | Contract	2,063
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ 10,477,483
% of Capital	2.39%
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | Foreign Contracts [Member] | LME Tin Futures LT April 2019 contracts, expiring April 2019 [Member]
Notional Amount	$ 33,478,866
Number of Contracts | Contract	345
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ 3,517,209
% of Capital	0.80%
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | Foreign Contracts [Member] | LME Zinc Futures LX May 2019 contracts, expiring May 2019 [Member]
Notional Amount	$ 33,015,122
Number of Contracts | Contract	537
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ 6,638,971
% of Capital	1.52%
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | Foreign Contracts [Member] | LME Nickel Futures LN November 2019 contracts, expiring November 2019
Notional Amount	$ 31,441,758
Number of Contracts | Contract	399
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ (41,962)
% of Capital	(0.01%)
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | Foreign Contracts [Member] | LME Tin Futures LT November 2019 contracts, expiring November 2019
Notional Amount	$ 31,726,430
Number of Contracts | Contract	298
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ 46,995
% of Capital	0.01%
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | Foreign Contracts [Member] | ICE Brent Crude Oil Futures CO April 2020 contracts, expiring February 2020 [Member]
Notional Amount	$ 31,371,210
Number of Contracts | Contract	484
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ 316,270
% of Capital	0.07%
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member]
Notional Amount	$ 316,311,199
Number of Contracts | Contract	9,122
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ (6,167,234)
% of Capital	(1.41%)
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member] | NYMEX Heating Oil Futures HO June 2019 contracts, expiring May 2019
Notional Amount	$ 31,469,605
Number of Contracts | Contract	378
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ (117,680)
% of Capital	(0.03%)
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member] | COMEX Gold Futures GC June 2019 contracts, expiring June 2019
Notional Amount	$ 31,790,300
Number of Contracts | Contract	239
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ (756,150)
% of Capital	(0.17%)
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member] | CME Live Cattle Futures LC June 2019 contracts, expiring June 2019
Notional Amount	$ 31,373,750
Number of Contracts | Contract	655
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ (195,750)
% of Capital	(0.04%)
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member] | ICE Sugar #11 Futures SB July 2019 contracts, expiring June 2019
Notional Amount	$ 31,305,378
Number of Contracts | Contract	2,217
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ (69,407)
% of Capital	(0.02%)
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member] | CBOT Wheat Futures W July 2019 contracts, expiring July 2019
Notional Amount	$ 34,742,825
Number of Contracts | Contract	1,333
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ (3,850,550)
% of Capital	(0.88%)
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member] | CME Lean Hogs Futures LH July 2019 contracts, expiring July 2019
Notional Amount	$ 38,090
Number of Contracts | Contract	1
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ (1,210)
% of Capital	0.00%	[1]
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member] | CME Lean Hogs Futures LH August 2019 contracts, expiring August 2019
Notional Amount	$ 30,743,420
Number of Contracts | Contract	797
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ (1,079,080)
% of Capital	(0.25%)
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member] | CME Feeder Cattle Futures FC August 2019 contracts, expiring August 2019
Notional Amount	$ 30,741,500
Number of Contracts | Contract	405
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ 899,125
% of Capital	0.21%
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member] | NYMEX RBOB Gasoline Futures RB October 2019 contracts, expiring September 2019
Notional Amount	$ 31,360,304
Number of Contracts | Contract	446
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ 133,808
% of Capital	0.03%
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member] | CBOT Corn Futures C December 2019 contracts, expiring December 2019 [Member]
Notional Amount	$ 31,375,337
Number of Contracts | Contract	1,581
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ (960,850)
% of Capital	(0.22%)
United States Commodity Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG March 2020 contracts, expiring February 2020
Notional Amount	$ 31,370,690
Number of Contracts | Contract	1,070
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ (169,490)
% of Capital	(0.04%)
United States Commodity Index Fund [Member] | Open Futures Contracts - Short [Member] | Foreign Contracts [Member]
Notional Amount	$ (43,809,241)	[2]
Number of Contracts | Contract	446	[2]
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ (648,130)	[2]
% of Capital	(0.15%)	[2]
United States Commodity Index Fund [Member] | Open Futures Contracts - Short [Member] | Foreign Contracts [Member] | LME Tin Futures LT April 2019 contracts, expiring April 2019 [Member]
Notional Amount	$ (36,844,065)	[2]
Number of Contracts | Contract	345	[2]
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ (153,680)	[2]
% of Capital	(0.04%)	[2]
United States Commodity Index Fund [Member] | Open Futures Contracts - Short [Member] | Foreign Contracts [Member] | LME Zinc Futures LX May 2019 contracts, expiring May 2019 [Member]
Notional Amount	$ (6,965,176)	[2]
Number of Contracts | Contract	101	[2]
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ (494,450)	[2]
% of Capital	(0.11%)	[2]
United States Commodity Index Fund [Member] | Open Futures Contracts [Member]
Notional Amount	$ 433,535,344	[3]
Number of Contracts | Contract	11,631	[3]
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ 3,662,119	[3]
% of Capital	0.83%	[3]
United States Commodity Index Fund [Member] | Cash Equivalents [Member]
Market Value	$ 439,767,236
% of Capital	100.23%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member]
Market Value	$ 416,017,236
% of Capital	94.82%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.41%, 4/04/2019 [Member]
Principal Amount	$ 16,000,000
Market Value	$ 15,996,817
% of Capital	3.65%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.43%, 4/11/2019 [Member]
Principal Amount	$ 30,000,000
Market Value	$ 29,979,917
% of Capital	6.83%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.36%, 4/18/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,988,926
% of Capital	2.28%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.33%, 4/25/2019 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,969,187
% of Capital	4.55%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.46%, 5/02/2019 [Member]
Principal Amount	$ 23,000,000
Market Value	$ 22,951,971
% of Capital	5.23%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.44%, 5/09/2019 [Member]
Principal Amount	$ 37,000,000
Market Value	$ 36,905,639
% of Capital	8.41%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.43%, 5/23/2019 [Member]
Principal Amount	$ 40,000,000
Market Value	$ 39,860,756
% of Capital	9.08%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.42%, 5/30/2019 [Member]
Principal Amount	$ 8,000,000
Market Value	$ 7,968,468
% of Capital	1.82%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.51%, 6/06/2019 [Member]
Principal Amount	$ 6,000,000
Market Value	$ 5,972,775
% of Capital	1.36%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.41%, 6/13/2019 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,878,840
% of Capital	5.67%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.41%, 6/20/2019 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,867,222
% of Capital	5.67%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.49%, 6/27/2019 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,851,375
% of Capital	5.66%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.44%, 7/05/2019 [Member]
Principal Amount	$ 12,000,000
Market Value	$ 11,923,525
% of Capital	2.72%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.46%, 7/11/2019 [Member]
Principal Amount	$ 42,000,000
Market Value	$ 41,713,223
% of Capital	9.51%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.42%, 7/18/2019 [Member]
Principal Amount	$ 28,000,000
Market Value	$ 27,798,399
% of Capital	6.34%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.44%, 7/25/2019 [Member]
Principal Amount	$ 21,000,000
Market Value	$ 20,838,329
% of Capital	4.75%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.46%, 8/08/2019 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,782,312
% of Capital	5.65%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.47%, 8/15/2019 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,769,555
% of Capital	5.64%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States - Money Market Funds [Member]
Market Value	$ 23,750,000
% of Capital	5.41%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States - Money Market Funds [Member] | Fidelity Investments Money Market Funds - Government Portfolio [Member]
Principal Amount	$ 7,200,000
Market Value	$ 7,200,000
% of Capital	1.64%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States - Money Market Funds [Member] | Goldman Sachs Financial Square Funds - Government Fund - Class FS [Member]
Principal Amount	$ 8,550,000
Market Value	$ 8,550,000
% of Capital	1.95%
United States Commodity Index Fund [Member] | Cash Equivalents [Member] | United States - Money Market Funds [Member] | Morgan Stanley Institutional Liquidity Funds - Government Portfolio [Member]
Principal Amount	$ 8,000,000
Market Value	$ 8,000,000
% of Capital	1.82%
United States Copper Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member]
Notional Amount	$ 15,925,775	[4]
Number of Contracts | Contract	224	[4]
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ 532,625	[4]
% of Capital	3.22%	[4]
United States Copper Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member] | COMEX Copper Futures HG May 2019 contracts expiring May 2019 [Member]
Notional Amount	$ 7,741,162
Number of Contracts | Contract	112
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ 479,637
% of Capital	2.90%
United States Copper Index Fund [Member] | Open Futures Contracts – Long [Member] | United States Contracts [Member] | COMEX Copper Futures HG July 2019 contracts expiring July 2019 [Member]
Notional Amount	$ 8,184,613
Number of Contracts | Contract	112
Value/Unrealized Gain (Loss) on Open Commodity Contracts	$ 52,988
% of Capital	0.32%
United States Copper Index Fund [Member] | Cash Equivalents [Member]
Market Value	$ 15,330,079
% of Capital	92.77%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member]
Market Value	$ 12,575,079
% of Capital	76.10%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.40%, 4/04/2019 [Member]
Principal Amount	$ 500,000
Market Value	$ 499,901
% of Capital	3.03%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.43%, 4/11/2019 [Member]
Principal Amount	$ 500,000
Market Value	$ 499,666
% of Capital	3.02%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.44%, 4/18/2019 [Member]
Principal Amount	$ 500,000
Market Value	$ 499,429
% of Capital	3.02%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.36%, 4/25/2019 [Member]
Principal Amount	$ 600,000
Market Value	$ 599,068
% of Capital	3.63%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.41%, 5/02/2019 [Member]
Principal Amount	$ 600,000
Market Value	$ 598,765
% of Capital	3.62%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.38%, 5/16/2019 [Member]
Principal Amount	$ 500,000
Market Value	$ 498,715
% of Capital	3.02%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.47%, 5/09/2019 [Member]
Principal Amount	$ 400,000
Market Value	$ 398,817
% of Capital	2.41%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.45%, 5/23/2019 [Member]
Principal Amount	$ 600,000
Market Value	$ 597,899
% of Capital	3.62%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.42%, 5/30/2019 [Member]
Principal Amount	$ 500,000
Market Value	$ 498,029
% of Capital	3.01%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.41%, 6/06/2019 [Member]
Principal Amount	$ 500,000
Market Value	$ 497,807
% of Capital	3.01%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.41%, 6/13/2019 [Member]
Principal Amount	$ 700,000
Market Value	$ 696,608
% of Capital	4.22%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.44%, 6/20/2019 [Member]
Principal Amount	$ 700,000
Market Value	$ 696,229
% of Capital	4.21%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.49%, 6/27/2019 [Member]
Principal Amount	$ 400,000
Market Value	$ 397,622
% of Capital	2.41%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.44%, 7/05/2019 [Member]
Principal Amount	$ 500,000
Market Value	$ 496,814
% of Capital	3.01%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.48%, 7/11/2019 [Member]
Principal Amount	$ 350,000
Market Value	$ 347,595
% of Capital	2.10%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.42%, 7/18/2019 [Member]
Principal Amount	$ 250,000
Market Value	$ 248,200
% of Capital	1.50%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.44%, 7/25/2019 [Member]
Principal Amount	$ 300,000
Market Value	$ 297,690
% of Capital	1.80%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.46%, 8/08/2019 [Member]
Principal Amount	$ 500,000
Market Value	$ 495,646
% of Capital	3.00%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.54%, 8/15/2019 [Member]
Principal Amount	$ 550,000
Market Value	$ 544,817
% of Capital	3.30%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.42%, 8/22/2019 [Member]
Principal Amount	$ 1,200,000
Market Value	$ 1,188,562
% of Capital	7.19%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.48%, 9/05/2019 [Member]
Principal Amount	$ 300,000
Market Value	$ 296,795
% of Capital	1.80%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.48%, 9/12/2019 [Member]
Principal Amount	$ 500,000
Market Value	$ 494,431
% of Capital	2.99%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.46%, 9/19/2019 [Member]
Principal Amount	$ 500,000
Market Value	$ 494,229
% of Capital	2.99%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.41%, 9/26/2019 [Member]
Principal Amount	$ 700,000
Market Value	$ 691,745
% of Capital	4.19%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States - Money Market Funds [Member]
Market Value	$ 2,755,000
% of Capital	16.67%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States - Money Market Funds [Member] | Goldman Sachs Financial Square Funds - Government Fund - Class FS [Member]
Principal Amount	$ 1,520,000
Market Value	$ 1,520,000
% of Capital	9.20%
United States Copper Index Fund [Member] | Cash Equivalents [Member] | United States - Money Market Funds [Member] | Morgan Stanley Institutional Liquidity Funds - Government Portfolio [Member]
Principal Amount	$ 1,235,000
Market Value	$ 1,235,000
% of Capital	7.47%

[1] Represents less than 0.005%.

[2] All short contracts are offset by long positions in Futures Contracts and are acquired solely for the purpose of reducing a long position (e.g., due to a redemption or to reflect a rebalancing of the SDCI).

[3] Collateral amounted to $35,952,692 on open futures contracts.

[4] Collateral amounted to $599,223 on open futures contracts.