XML 56 R45.htm IDEA: XBRL DOCUMENT v3.20.2
Employee Benefits - Additional Information (Details) - USD ($)
3 Months Ended 9 Months Ended
Mar. 31, 2020
Sep. 30, 2020
Sep. 30, 2019
Dec. 31, 2019
Defined Benefit Plan Disclosure        
Payment for Other Postretirement Benefits   $ 2,900,000 $ 2,100,000  
Postretirement Health Coverage | Salaried VEBA        
Defined Benefit Plan Disclosure        
Maximum contribution threshold   2,900,000    
Payment for Other Postretirement Benefits $ 2,900,000      
Level 2 | Fair Value, Measurements, Recurring        
Defined Benefit Plan Disclosure        
Fair value of deferred compensation assets   9,100,000   $ 8,100,000
Accrued salaries, wages and related expenses        
Defined Benefit Plan Disclosure        
Accrued salaries, wages and related expenses   $ 3,700,000