XML 102 R75.htm IDEA: XBRL DOCUMENT v3.20.4
Pension Plans and Other Postretirement Benefits (Details-4)
$ in Thousands
12 Months Ended
Dec. 31, 2020
USD ($)
concentration
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Other postretirement benefits [Abstract]      
Fair value of plan assets $ 481,273 $ 434,922  
Pension Benefits [Member]      
Defined Benefit Plan, Information about Plan Assets [Abstract]      
Target Plan Asset Allocation 100.00%    
Actual Plan Asset Allocation 100.00% 100.00%  
Other postretirement benefits [Abstract]      
Fair value of plan assets $ 429,538 $ 386,033 $ 323,780
Pension Benefits [Member] | Plan Assets [Member]      
Concentration of Credit Risk [Abstract]      
Concentration risk, percentage 10.00%    
Concentration risk, number of significant concentrations | concentration 0    
Pension Benefits [Member] | Equity Securities [Member]      
Defined Benefit Plan, Information about Plan Assets [Abstract]      
Target Plan Asset Allocation [1] 63.00%    
Actual Plan Asset Allocation 69.00% 64.00%  
Pension Benefits [Member] | United States Equity Securities [Member]      
Defined Benefit Plan, Information about Plan Assets [Abstract]      
Target Plan Asset Allocation 45.50%    
Pension Benefits [Member] | Non-United States Equity Securities [Member]      
Defined Benefit Plan, Information about Plan Assets [Abstract]      
Target Plan Asset Allocation 17.50%    
Pension Benefits [Member] | Fixed Income Securities [Member]      
Defined Benefit Plan, Information about Plan Assets [Abstract]      
Target Plan Asset Allocation 30.00%    
Actual Plan Asset Allocation 25.00% 29.00%  
Pension Benefits [Member] | Real Estate [Member]      
Defined Benefit Plan, Information about Plan Assets [Abstract]      
Target Plan Asset Allocation 7.00%    
Actual Plan Asset Allocation 6.00% 7.00%  
Postretirement Benefits [Member]      
Other postretirement benefits [Abstract]      
Fair value of plan assets $ 51,735 $ 48,889 $ 42,521
Postretirement Benefits [Member] | Plan Assets [Member]      
Concentration of Credit Risk [Abstract]      
Concentration risk, percentage 10.00%    
Concentration risk, number of significant concentrations | concentration 0    
Master Pension Trust [Member]      
Other postretirement benefits [Abstract]      
Fair value of plan assets $ 45,600 $ 42,800  
[1] Target allocations for equity securities are broken out as follows: 45.5% United States equity and 17.5% non-United States equity.