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Capital Transactions - Additional Information (Detail)
$ / shares in Units, $ in Thousands
3 Months Ended 12 Months Ended
Apr. 30, 2008
Mar. 31, 2019
shares
Dec. 30, 2018
USD ($)
Vote
Stock
$ / shares
shares
Dec. 31, 2017
USD ($)
$ / shares
shares
Jan. 01, 2017
USD ($)
$ / shares
shares
Capital Transactions [Line Items]          
Share based compensation     $ 5,606 $ 7,922 $ 7,154
Number of classes of common stock outstanding | Stock     2    
Dividend is declared and paid on the Common Stock | $ / shares     $ 1.00 $ 1.00 $ 1.00
Payment of dividend     $ 9,353 $ 9,328 $ 9,307
Number of votes per share | Vote     1    
Long-Term Performance Equity Plan [Member]          
Capital Transactions [Line Items]          
Award settled in cash or shares, average closing prices of shares during trading days of performance period     20 days    
Long-Term Performance Equity Plan [Member] | Selling Delivery and Administrative Expenses [Member]          
Capital Transactions [Line Items]          
Share based compensation     $ 2,000    
Class B Common Stock [Member]          
Capital Transactions [Line Items]          
Final potential award issued based on the performence unit | shares     36,800 40,000 40,000
Performance unit award agreement expiration period 2018        
Dividend is declared and paid on the Common Stock | $ / shares     $ 1.00 $ 1.00 $ 1.00
Number of votes per share | Vote     20    
Class B Common Stock [Member] | Scenario Forecast [Member]          
Capital Transactions [Line Items]          
Final potential award issued based on the performence unit | shares   40,000