XML 118 R101.htm IDEA: XBRL DOCUMENT v3.20.4
Employee Benefit Plans - Narrative (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]      
Actual return on plan assets (percent) 12.70% 18.10%  
Defined Contribution 401k Plan      
Defined Benefit Plan Disclosure [Line Items]      
Employer matching contribution (percent) 3.00%    
Company's matching contribution expense $ 0.6 $ 0.2 $ 0.6
Cash Balance Pension Plan      
Defined Benefit Plan Disclosure [Line Items]      
Employer matching contribution (percent) 3.00%    
Company's matching contribution expense $ 0.7 0.0 0.0
Grace 401(k) Plans      
Defined Benefit Plan Disclosure [Line Items]      
Company's matching contribution expense $ 1.1 1.1 1.8
Company's maximum annual contributions per employee (percent) 10.00%    
Deferred Profit Sharing      
Defined Benefit Plan Disclosure [Line Items]      
Company's matching contribution expense $ 0.5 $ 0.3 $ 0.4
Deferred Profit Sharing | Minimum      
Defined Benefit Plan Disclosure [Line Items]      
Employer matching contribution (percent) 1.00%    
Deferred Profit Sharing | Maximum      
Defined Benefit Plan Disclosure [Line Items]      
Employer matching contribution (percent) 5.00%    
Pension Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Expected return on plan assets 3.70% 4.30% 4.30%
Accumulated benefit obligation $ 218.7 $ 204.4  
Employer contributions $ 0.0 $ 0.0 $ 0.0