XML 32 R21.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Service Providers and Related Party Agreements - Additional Information (Detail)
12 Months Ended
Dec. 31, 2019
Sponsor | Accrued Professional Fees  
Related Party Transaction [Line Items]  
Sponsor's fee accrues daily and paid monthly, annual nominal Rate 0.40%