Annual report pursuant to Section 13 and 15(d)

Dispositions Dispositions (Details)

v3.20.4
Dispositions Dispositions (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 19, 2019
Jun. 28, 2019
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Jul. 01, 2020
Dec. 30, 2019
Dispositions [Line Items]              
Pre-tax gain on sale     $ 4,958        
Deferred revenue     13,388 $ 6,450      
Net cash proceeds from sale of product line     18,000 27,658 $ 0    
Net cash proceeds from sale of property     9,375 17,600 $ 12,380    
Property, plant and equipment, net     983,235 1,011,156      
Right-of-use lease asset     48,239 $ 48,417      
Operating lease liability     $ 47,213        
Sulfate salts product line | Disposed of by sale, not discontinued operations              
Dispositions [Line Items]              
Sale consideration   $ 28,000          
Pre-tax gain on sale   11,518          
Deferred revenue   9,000          
Net cash proceeds from sale of product line   27,658          
Net working capital   4,215          
Property, plant and equipment, net   $ 3,276          
Property sale | Disposed of by sale, not discontinued operations              
Dispositions [Line Items]              
Sale consideration $ 19,100            
Pre-tax gain on sale 7,150            
Net cash proceeds from sale of property 17,100            
Property, plant and equipment, net             $ 10,735
Holdback receivable $ 1,000            
Right-of-use lease asset             3,588
Operating lease liability             $ 3,524
Magnesium silicate product line | Disposed of by sale, not discontinued operations              
Dispositions [Line Items]              
Sale consideration           $ 18,000  
Inventory, Gross           1,556  
Deferred revenue           $ 11,486