XML 68 R57.htm IDEA: XBRL DOCUMENT v3.20.2
Commitments and Contingencies - Additional Information (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Aug. 06, 2020
Sep. 30, 2020
Sep. 30, 2020
Environmental Contingency      
Environmental accrual increased during the period   $ 3.8  
Environmental accrual   20.7 $ 20.7
Expected period related to remediation expenditures for environmental contingencies period     30 years
Potential increase in environmental costs   11.6 $ 11.6
Time period within which recorded estimate of its obligation may change     12 months
Comprehensive Environmental Response, Compensation and Liability Act      
Environmental Contingency      
Environmental accrual   1.9 $ 1.9
Environmental accrual remained   $ 1.2 $ 1.2
Comprehensive Environmental Response, Compensation and Liability Act | Administrative Settlement Agreement      
Environmental Contingency      
Consent for Removal Actions, first phase estimated completion period 3 months    
Minimum      
Environmental Contingency      
Period for final feasibility study     12 months
Maximum      
Environmental Contingency      
Period for final feasibility study     24 months