Quarterly report pursuant to Section 13 or 15(d)

Shareholders' Equity - Summary of Changes in Shareholders' Equity (Details)

v3.8.0.1
Shareholders' Equity - Summary of Changes in Shareholders' Equity (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 9 Months Ended 18 Months Ended
Sep. 30, 2017
Oct. 01, 2016
Sep. 30, 2017
Oct. 01, 2016
Aug. 28, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Beginning of Period     $ 337,449    
Foreign Currency Translation Adjustment $ 1,496 $ 49 3,987 $ 1,354  
Retirement Liability Adjustment – Net of Tax 130 130 392 392  
Net Income 6,060 $ 12,074 25,332 $ 38,539  
End of Period $ 337,330   $ 337,330    
Common Stock          
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
End of Period (in shares) 21,075,000   21,075,000    
Convertible Class B Stock          
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
End of Period (in shares) 6,927,000   6,927,000    
COMMON STOCK          
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Beginning of Period     $ 297    
Conversion of Class B Shares to Common Shares     0    
Exercise of Stock Options     0    
End of Period $ 297   $ 297    
COMMON STOCK | Common Stock          
Class of Stock [Line Items]          
Shares Authorized (in shares) 40,000,000   40,000,000    
Share Par Value (in usd per share) $ 0.01   $ 0.01    
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Beginning of Period (in shares)     21,955,000    
Conversion of Class B Shares to Common Shares (in shares)     777,000    
Exercise of Stock Options (in shares)     18,000    
End of Period (in shares) 22,750,000   22,750,000    
COMMON STOCK | Convertible Class B Stock          
Class of Stock [Line Items]          
Shares Authorized (in shares) 15,000,000   15,000,000    
Share Par Value (in usd per share) $ 0.01   $ 0.01    
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Beginning of Period (in shares)     7,665,000    
Conversion of Class B Shares to Common Shares (in shares)     (777,000)    
Exercise of Stock Options (in shares)     39,000    
End of Period (in shares) 6,927,000   6,927,000    
ADDITIONAL PAID IN CAPITAL          
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Beginning of Period     $ 64,752    
Exercise of Stock Options     349    
Stock Compensation Expense     2,203    
End of Period $ 67,304   67,304    
ACCUMULATED OTHER COMPREHENSIVE LOSS          
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Beginning of Period     (15,494)    
Foreign Currency Translation Adjustment     3,987    
Retirement Liability Adjustment – Net of Tax     392    
End of Period (11,115)   (11,115)    
RETAINED EARNINGS          
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Beginning of Period     305,512    
Net Income     25,332    
End of Period 330,844   330,844    
TREASURY STOCK          
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Beginning of Period     $ (17,618)    
Beginning of Period (in shares)     523,000    
Purchase     $ (32,382)   $ (50,000)
Purchase (in shares)     (1,152,000)   (1,675,000)
End of Period $ (50,000)   $ (50,000)    
End of Period (in shares) 1,675,000   1,675,000