Summary of Significant Accounting Policies (Details)	9 Months Ended
	Sep. 30, 2017 USD ($)
Maximum [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Offering Costs as Percentage of Month-end Net Asset Value	0.50%
Held by Wells Fargo Bank N.A. [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Investments and Cash	$ 778,000