Annual report pursuant to Section 13 and 15(d)

Borrowings - Additional Information (Details)

v3.8.0.1
Borrowings - Additional Information (Details) - USD ($)
 12 Months Ended
Dec. 30, 2017
Nov. 15, 2016
Dec. 30, 2017
Dec. 31, 2016
Line of Credit Facility [Line Items]        
Revolving loan payable $ 0   $ 0 $ 0
Minimum availability required trigger amount (if less than)   $ 2,400,000    
Number of consecutive days excess availability is above required amount   45 days    
Capital leases payable 9,752,000   9,752,000  
JPMorgan Chase Bank | Revolving Line of Credit Facility        
Line of Credit Facility [Line Items]        
Maximum borrowing capacity   $ 30,000,000    
Revolving loan payable $ 0   $ 0  
Unused capacity commitment fee percentage 0.25%      
Minimum availability required trigger amount (if less than)   $ 3,600,000    
Consecutive business days below minimum excess availability   3 days    
Number of consecutive days excess availability is above required amount   60 days    
Limited security by foreign subsidiaries' capital stock percentage     65.00%  
One-Month London Interbank Offered Rate (LIBOR) | JPMorgan Chase Bank | Revolving Line of Credit Facility        
Line of Credit Facility [Line Items]        
Applicable margin for LIBOR-based interest rate/ Applicable margin for Alternate base rate     1.75%  
London Interbank Offered Rate (LIBOR) | JPMorgan Chase Bank | Revolving Line of Credit Facility        
Line of Credit Facility [Line Items]        
Interest rate 3.31%   3.31%  
LIBOR based interest rate, principal $ 0      
Base Rate | JPMorgan Chase Bank | Revolving Line of Credit Facility        
Line of Credit Facility [Line Items]        
Applicable margin for LIBOR-based interest rate/ Applicable margin for Alternate base rate     0.25%  
Interest rate 4.75%   4.75%  
Prime based rate principal $ 0