XML 69 R56.htm IDEA: XBRL DOCUMENT v3.21.2
Commitments and Contingencies - Additional Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2021
Sep. 30, 2021
Oct. 28, 2021
Dec. 31, 2020
Loss Contingencies [Line Items]        
Environmental remediation liabilities - discounted $ 38,200 $ 38,200   $ 39,200
Accrual for environmental loss contingencies - weighted-average discount rate 3.50% 3.50%    
Environmental remediation liabilities - undiscounted $ 71,200 $ 71,200   73,600
Loss Contingency, Loss in Period 657,412 657,412    
Loss Contingencies, Loss in Period, Net of Tax 504,500 504,500    
Subsequent Event        
Loss Contingencies [Line Items]        
Loss Contingency, Estimate of Possible Loss     $ 600,000  
Minimum        
Loss Contingencies [Line Items]        
Potential revision on future environmental remediation costs before tax   10,000    
Maximum        
Loss Contingencies [Line Items]        
Potential revision on future environmental remediation costs before tax   37,000    
Other noncurrent liabilities        
Loss Contingencies [Line Items]        
Tax Indemnification Liability $ 27,900 $ 27,900   $ 30,500