Unaudited Schedule of Investments - Future Contracts (Parenthetical)	6 Months Ended					12 Months Ended
	Jun. 30, 2014 ICE-UK Brent Crude (767 contracts, settlement date November 13, 2014) [Member] Contract	Jun. 30, 2014 NYMEX Natural Gas (921 contracts, settlement date September 26, 2014) [Member] Contract	Jun. 30, 2014 NYMEX NY Harbor (666 contracts, settlement date May 29, 2015) [Member] Contract	Jun. 30, 2014 NYMEX RBOB Gasoline (741 contracts, settlement date November 28, 2014) [Member] Contract	Jun. 30, 2014 NYMEX WTI Crude (872 contracts, settlement date December 19, 2014) [Member] Contract	Dec. 31, 2013 ICE-UK Brent Crude (568 contracts, settlement date March 14, 2014) [Member] Contract	Dec. 31, 2013 NYMEX Natural Gas (706 contracts, settlement date September 26, 2014) [Member] Contract	Dec. 31, 2013 NYMEX NY Harbor ULSD (491 contracts, settlement date March 31, 2014) [Member] Contract	Dec. 31, 2013 NYMEX RBOB Gasoline (568 contracts, settlement date November 28, 2014) [Member] Contract	Dec. 31, 2013 NYMEX WTI Crude (633 contracts, settlement date June 20, 2014) [Member] Contract
Schedule of Investments [Line Items]
Open Option Contracts Written, Number of Contracts	767	921	666	741	872	568	706	491	568	633
Forward Contract Indexed to Issuer's Equity, Settlement Date or Dates	Nov. 13, 2014	Sep. 26, 2014	May 29, 2015	Nov. 28, 2014	Dec. 19, 2014	Mar. 14, 2014	Sep. 26, 2014	Mar. 31, 2014	Nov. 28, 2014	Jun. 20, 2014