Service Providers and Related Party Agreements - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Related Party Transactions [Abstract]
Management fee percentage per annum of daily NAV			0.75%
Managing owner waived fees	$ 1,707	$ 0	$ 2,822	$ 0