Quarterly report pursuant to Section 13 or 15(d)

Shareholders' Equity - Components of Accumulated Other Comprehensive Income (Loss) (Details)

v3.20.2
Shareholders' Equity - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Thousands
Sep. 26, 2020
Jun. 27, 2020
Dec. 31, 2019
Sep. 28, 2019
Jun. 29, 2019
Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]            
Accumulated other comprehensive income $ 289,846   $ 388,857 $ 425,792    
Foreign Currency Translation Adjustments            
Accumulated Other Comprehensive Income (Loss) [Line Items]            
Accumulated other comprehensive income (7,127)   (7,042)      
Retirement Liability Adjustment            
Accumulated Other Comprehensive Income (Loss) [Line Items]            
Retirement Liability Adjustment – Before Tax (10,051)   (10,868)      
Tax Benefit of Retirement Liability Adjustment 2,110   2,282      
Accumulated other comprehensive income (7,941)   (8,586)      
Accumulated Comprehensive Loss            
Accumulated Other Comprehensive Income (Loss) [Line Items]            
Accumulated other comprehensive income $ (15,068) $ (16,692) $ (15,628) $ (13,610) $ (12,421) $ (13,329)