Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Details)

v3.20.2
Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)
 3 Months Ended
Sep. 03, 2020
Sep. 19, 2019
Sep. 30, 2020
Sep. 30, 2019
Jun. 30, 2020
Summary Of Significant Accounting Policies [Line Items]          
Restricted cash     $ 200,000   $ 200,000
Notice period to terminate contract     14 days    
Precious metals held under financing arrangements [1]     $ 158,756,000   $ 178,577,000
Lease cost     500,000    
Operating lease cost     300,000    
Operating lease payments     $ 400,000    
Operating lease term (in years)     4 years 3 months 18 days    
Operating lease (percent)     4.90%    
Metals purchase by customer maximum specified time period     1 year    
Metal delivers to customer after receiving customers deposit based on prevailing current spot price percentage     110.00%    
Unpriced metal is subject to margin call If deposit falls below percentage of value of unpriced metal     105.00%    
Percentage to remit partial payment of total order price     20.00%    
Advertising expense     $ 700,000 $ 463,000  
Cost of sales     $ 1,829,971,000 1,472,674,000  
Dividends declared, date Sep. 03, 2020        
Dividends declared $ 1.50   $ 1.50    
Dividends payable, date of record Sep. 21, 2020        
Dividends payable, date to be paid Sep. 25, 2020        
Dividends paid     $ 10,600,000    
Change in accounting principle, accounting standards update, adopted     true    
Change in accounting principle, accounting standards update, immaterial effect     true    
Accounting standards update [Extensible List]     us-gaap:AccountingStandardsUpdate201815Member    
Shipping and Handling          
Summary Of Significant Accounting Policies [Line Items]          
Cost of sales     $ 3,200,000 $ 1,400,000  
Convertible Revolving Credit Facility          
Summary Of Significant Accounting Policies [Line Items]          
Line of credit facility, maximum borrowing capacity   $ 4,000,000      
Line of credit facility, interest rate   12.00%      
Line of credit facility, expiration date   Sep. 18, 2022      
Line of credit facility, percentage of outstanding principal converted into borrower's issued and outstanding common stock   22.00%      
Line of credit facility, percentage of repay outstanding unrelated third-party debt in exchange for borrower's issued and outstanding common stock   27.50%      
Line of credit facility, additional interest rate in case of default by borrower   10.00%      
Line of credit facility, entitlement of interest to lender in event of excess gross sales price   $ 9,900,000      
Minimum          
Summary Of Significant Accounting Policies [Line Items]          
Estimated useful lives of related assets     3 years    
Estimated useful lives of intangibles     3 years    
Percentage of investments in privately-held entities accounted under equity method     20.00%    
Maximum          
Summary Of Significant Accounting Policies [Line Items]          
Estimated useful lives of related assets     25 years    
Estimated useful lives of intangibles     15 years    
Percentage of investments in privately-held entities accounted under equity method     50.00%    
Customer locks period for purchase price     2 years    
[1] Includes amounts of the consolidated variable interest entity, which is presented separately in the table below.