XML 94 R81.htm IDEA: XBRL DOCUMENT v3.20.4
Employee Benefits (Details) - USD ($)
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]      
Defined contribution plan wage base $ 285,000 $ 280,000 $ 275,000
Requisite service period (in years) 3 years    
Expenses under defined contribution plan $ 2,200,000 1,900,000 1,800,000
Nonqualified Plan      
Defined Benefit Plan Disclosure [Line Items]      
Employer contribution percentage to retirement plan 18.90%    
Maximum gross annual base salary under plan $ 500,000    
Expenses for NQDC plan 200,000 $ 100,000 $ 100,000
Nonqualified Plan | Chief Executive Officer      
Defined Benefit Plan Disclosure [Line Items]      
Maximum gross annual base salary under plan $ 700,000    
Base Percentage      
Defined Benefit Plan Disclosure [Line Items]      
Employer contribution percentage to retirement plan 13.20%    
Excess Percentage for amounts above Social Security taxable wage base      
Defined Benefit Plan Disclosure [Line Items]      
Employer contribution percentage to retirement plan 5.70%