v3.26.1
Statements of Changes in Capital - USD ($)
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
United States Commodity Index Fund        
Balances at beginning of period     $ 278,945,743  
Net income (loss) $ (11,331,827) $ 3,584,973 53,384,741 $ 21,683,348
Balances at end of period 337,396,879   337,396,879  
United States Copper Index Fund        
Balances at beginning of period     456,411,715  
Net income (loss) 65,293,972 (1,639,626) 33,126,001 34,384,313
Balances at end of period 724,734,128   724,734,128  
United States Commodity Index Funds Trust        
Balances at beginning of period     735,357,458  
Net income (loss) 53,962,145 1,945,347 86,510,742 56,067,661
Balances at end of period 1,062,131,007   1,062,131,007  
Shareholders | United States Commodity Index Fund        
Balances at beginning of period 347,986,922 [1] 237,605,201 [1] 278,945,743 191,518,010
Addition 24,620,114 [1] 7,328,820 [1] 45,058,764 38,783,283
Redemption (23,878,330) [1] (6,774,067) [1] (39,992,369) (10,239,714)
Net income (loss) (11,331,827) [1] 3,584,973 [1] 53,384,741 21,683,348
Balances at end of period [1] 337,396,879 241,744,927 337,396,879 241,744,927
Shareholders | United States Copper Index Fund        
Balances at beginning of period 713,562,786 [1] 200,037,829 [1] 456,411,715 142,561,094
Addition 105,378,393 [1] 48,018,195 [1] 587,184,579 78,155,881
Redemption (159,501,023) [1] (30,887,129) [1] (351,988,167) (39,572,019)
Net income (loss) 65,293,972 [1] (1,639,626) [1] 33,126,001 34,384,313
Balances at end of period [1] 724,734,128 215,529,269 724,734,128 215,529,269
Shareholders | United States Commodity Index Funds Trust        
Balances at beginning of period 1,061,549,708 [1] 437,643,030 [1] 735,357,458 334,079,104
Addition 129,998,507 [1] 55,347,015 [1] 632,243,343 116,939,164
Redemption (183,379,353) [1] (37,661,196) [1] (391,980,536) (49,811,733)
Net income (loss) 53,962,145 [1] 1,945,347 [1] 86,510,742 56,067,661
Balances at end of period [1] $ 1,062,131,007 $ 457,274,196 $ 1,062,131,007 $ 457,274,196
[1] Sponsors’ shares outstanding and capital for the periods presented were zero.