Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

Document and Entity Information - USD ($)
$ in Thousands
12 Months Ended
Jun. 30, 2021
Sep. 03, 2021
Dec. 31, 2020
Cover [Abstract]      
Entity Registrant Name A-Mark Precious Metals, Inc.    
Entity Central Index Key 0001591588    
Entity Tax Identification Number 11-2464169    
Entity File Number 001-36347    
Current Fiscal Year End Date --06-30    
Entity Filer Category Accelerated Filer    
Document Type 10-K    
Document Period End Date Jun. 30, 2021    
Document Fiscal Year Focus 2021    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Small Business true    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Entity Shell Company false    
Entity Incorporation, State or Country Code DE    
Entity Address, Address Line One 2121 Rosecrans Ave    
Entity Address, Address Line Two Suite 6300    
Entity Address, City or Town El Segundo    
Entity Address, State or Province CA    
Entity Address, Postal Zip Code 90245    
City Area Code 310    
Local Phone Number 587-1477    
Title of 12(b) Security Common Stock, $0.01 par value    
Trading Symbol AMRK    
Security Exchange Name NASDAQ    
Entity Common Stock, Shares Outstanding   11,291,247  
Entity Public Float     $ 124,199,762
Document Annual Report true    
Document Transition Report false