FAIR VALUE OF FINANCIAL INSTRUMENTS (Fair Value of Derivative Instrument held by Usci, Cper, Usag and Usmi) (Details) - Commodity Contracts [Member] - Futures [Member] - Assets [Member] - USD ($)	Mar. 31, 2019	Dec. 31, 2018
United States Commodity Index Fund [Member]
Derivatives, Fair Value [Line Items]
Derivatives not Accounted for as Hedging Instruments	$ 3,662,119	$ (14,487,984)
United States Copper Index Fund [Member]
Derivatives, Fair Value [Line Items]
Derivatives not Accounted for as Hedging Instruments	$ 532,625	$ (903,475)

Fair value as of the balance sheet date of derivative instrument not designated as hedging instrument and classified as an asset.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959

Name:	us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant