Schedule of Investments (Unaudited) - Futures Contracts (Parenthetical) - Contract	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
CBOT Corn (7,180 contracts, settlement date September 14, 2016) [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts	7,180
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates	Sep. 14, 2016
CBOT Soybean (3,197 contracts, settlement date November 14, 2016) [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts	3,197
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates	Nov. 14, 2016
CBOT Wheat (4,853 contracts, settlement date July 14, 2017) [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts	4,853
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates	Jul. 14, 2017
COMEX Gold (1,821 contracts, settlement date August 29, 2016) [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts	1,821
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates	Aug. 29, 2016
COMEX Silver (682 contracts, settlement date January 27, 2017) [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts	682
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates	Jan. 27, 2017
ICE-UK Brent Crude (5,627 contracts, settlement date October 31, 2016) [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts	5,627
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates	Oct. 31, 2016
LME Aluminum (2,686 contracts, settlement date November 14, 2016) [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts	2,686
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates	Nov. 14, 2016
LME Copper (835 contracts, settlement date August 15, 2016) [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts	835
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates	Aug. 15, 2016
LME Zinc (2,455 contracts, settlement date December 19, 2016) [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts	2,455
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates	Dec. 19, 2016
NYB-ICE Sugar (9,198 contracts, settlement date September 30, 2016) [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts	9,198
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates	Sep. 30, 2016
NYMEX Natural Gas (5,275 contracts, settlement date August 29, 2016) [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts	5,275
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates	Aug. 29, 2016
NYMEX NY Harbor ULSD (4,484 contracts, settlement date May 31, 2017) [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts	4,484
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates	May 31, 2017
NYMEX RBOB Gasoline (5,155 contracts, settlement date November 30, 2016) [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts	5,155
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates	Nov. 30, 2016
NYMEX WTI Crude (4,908 contracts, settlement date February 21, 2017) [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts	4,908
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates	Feb. 21, 2017
CBOT Corn (6,348 contracts, settlement date September 14, 2016) [Member] | Total Commodity Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts		6,348
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates		Sep. 14, 2016
CBOT Soybean (2,828 contracts, settlement date November 14, 2016) [Member] | Total Commodity Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts		2,828
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates		Nov. 14, 2016
CBOT Wheat (4,833 contracts, settlement date July 14, 2016) [Member] | Total Commodity Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts		4,833
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates		Jul. 14, 2016
COMEX Gold (1,609 contracts, settlement date August 29, 2016) [Member] | Total Commodity Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts		1,609
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates		Aug. 29, 2016
COMEX Silver (607 contracts, settlement date March 29, 2016) [Member] | Total Commodity Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts		607
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates		Mar. 29, 2016
ICE-UK Brent Crude (4,973 contracts, settlement date October 31, 2016) [Member] | Total Commodity Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts		4,973
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates		Oct. 31, 2016
LME Aluminum (2,372 contracts, settlement date November 14, 2016) [Member] | Total Commodity Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts		2,372
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates		Nov. 14, 2016
LME Copper (738 contracts, settlement date February 15, 2016) [Member] | Total Commodity Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts		738
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates		Feb. 15, 2016
LME Zinc (2,225 contracts, settlement date February 15, 2016) [Member] | Total Commodity Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts		2,225
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates		Feb. 15, 2016
NYB-ICE Sugar (8,126 contracts, settlement date September 30, 2016) [Member] | Total Commodity Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts		8,126
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates		Sep. 30, 2016
NYMEX Natural Gas (4,663 contracts, settlement date August 29, 2016) [Member] | Total Commodity Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts		4,663
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates		Aug. 29, 2016
NYMEX NY Harbor ULSD (4,169 contracts, settlement date May 31, 2016) [Member] | Total Commodity Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts		4,169
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates		May 31, 2016
NYMEX RBOB Gasoline (4,557 contracts, settlement date November 30, 2016) [Member] | Total Commodity Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts		4,557
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates		Nov. 30, 2016
NYMEX WTI Crude (5,803 contracts, settlement date February 22, 2016) [Member] | Total Commodity Futures Contracts Purchased [Member]
Schedule of Investments [Line Items]
Open Future Contracts Written, Number of Contracts		5,803
Futures Contract Indexed to Issuer's Equity, Settlement Date or Dates		Feb. 22, 2016