Related Party Disclosures (Details)	12 Months Ended
Dec. 31, 2017
Management Fees
Monthly management fee	8.33%
Percent value of net assets of the Trust	0.35%
Threshold percent value of net assets of trust to calculate management fee	0.65%

The percentage of the value of net assets of the Trust that serves as a basis for calculating management fees (per the Trust Agreement).

No definition available.

Name:	phys_PercentValueOfNetAssetsOfTrust
Namespace Prefix:	phys_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration