XML 14 R1.htm IDEA: XBRL DOCUMENT v3.21.2
Document and Entity Information - USD ($)
 12 Months Ended
Jun. 30, 2021
Aug. 13, 2021
Cover [Abstract]    
Entity Registrant Name GraniteShares Platinum Trust  
Entity Central Index Key 0001690842  
Document Type 10-K  
Document Period End Date Jun. 30, 2021  
Amendment Flag false  
Current Fiscal Year End Date --06-30  
Entity Well-known Seasoned Issuer No  
Entity Voluntary Filers No  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business Flag false  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Shell Company false  
Entity Public Float $ 38,034,000  
Entity Common Stock, Shares Outstanding   3,600,000
Document Fiscal Period Focus FY  
Document Fiscal Year Focus 2021