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Commitments and Contingencies (Details)
1 Months Ended 3 Months Ended
Sep. 30, 2016
USD ($)
Dec. 31, 2020
USD ($)
Sep. 30, 2017
party
Environmental Exit Cost [Line Items]      
Loss contingency, receivable   $ 468,000  
Abrasive particle supply agreement      
Environmental Exit Cost [Line Items]      
Purchase obligation   21,695,000  
KMG-Bernuth      
Environmental Exit Cost [Line Items]      
Remediation expense recognized   0  
Estimated remediation cost $ 22,000,000.0    
Number of other parties in agreement | party     7
Estimated reserve, remaining   $ 553,000