XML 105 R88.htm IDEA: XBRL DOCUMENT v3.20.4
Deferred Compensation Plan (Details) - USD ($)
$ in Millions
1 Months Ended 12 Months Ended
Feb. 11, 2021
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Deferred Compensation Plan [Abstract]        
Percentage of participant's base salary contributed   10.00%    
Percentage of Company contributions that vest after ten years of service   50.00%    
Number of years of service to qualify for 50% vesting in Company contributions   10 years    
Percentage of Company contributions that vest annually thereafter   5.00%    
Minimum age for participant's unvested company contributions to fully vest   60 years    
Compensation expense   $ 2.3 $ 1.8 $ 1.1
Long-term deferred compensation liability   47.5 43.2  
Investment in Rabbi Trust   $ 45.5 $ 41.7  
Subsequent Event [Member]        
Deferred Compensation Plan [Abstract]        
Percentage of participant's base salary contributed 5.00%      
Percentage of Company contributions that vest after five years of service 20.00%      
Vesting period 5 years      
Participant's vesting percentage 100.00%      
Maximum [Member]        
Deferred Compensation Plan [Abstract]        
Percentage of participant's salary that can be deferred   80.00%    
Percentage of participant's bonus or director fees that can be deferred   100.00%    
Minimum [Member] | Subsequent Event [Member]        
Deferred Compensation Plan [Abstract]        
Number of years of service required for accelerated vesting above specified compensation level 10 years