Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Details Textual)

v3.22.2.2
Stock-Based Compensation (Details Textual) - USD ($)
$ / shares in Units, $ in Thousands
9 Months Ended
Oct. 01, 2022
Oct. 02, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Stock option granted, shares 102,000  
Stock-based compensation expense $ 6,212 $ 6,233
2012 Nonemployee Director Fees Plan [Member]    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Stock option granted, shares   20,375
Stock-based compensation expense   $ 1,586
2019 Equity Incentive Plan [Member]    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Stock option granted, shares 13,137  
Stock-based compensation expense $ 266  
Employee Stock Purchase Plan [Member]    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Rate of common stock at market value 85.00%  
Employee Stock Purchase Plan and U.K. Plan [Member]    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Number of shares purchased by employees 28,960 22,747
Weighted average price $ 54.29 $ 57.93
Share-based compensation expenses $ 272 $ 431
Ratio for additional common stock shares issued, under ESPP 6  
Monte Carlo Valuation Model [Member] | Minimum [Member]    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Vesting period 1 year  
Monte Carlo Valuation Model [Member] | Maximum [Member]    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Vesting period 3 years  
Time Based [Member]    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Vesting period 3 years  
Performance Based [Member]    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Vesting period 3 years  
RSUs [Member] | Minimum [Member]    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Target amount percentage 0.00%  
RSUs [Member] | Maximum [Member]    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Target amount percentage 200.00%  
Stock Options [Member]    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Recognized weighted average period (in years) 1 year 1 month 6 days  
Unrecognized compensation cost related to the stock options $ 2,495  
Stock Options [Member] | Monte Carlo Valuation Model [Member]    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Contractual term of stock options 10 years  
Unvested options 82,500  
Vested unexercised options 0  
Exercise price per share $ 50.60  
Options grant date fair value $ 2,334  
Stock Options [Member] | Black Scholes Valuation Model [Member]    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Vesting period 3 years  
Contractual term of stock options 10 years  
Unvested options 13,222  
Vested unexercised options 11,011  
Exercise prices per share, lower range limit $ 35.04  
Exercise prices per share, upper range limit $ 55.03  
Restricted Stock and Restricted Stock Units [Member]    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Compensation expense $ 5,566 $ 4,168
Total unrecognized compensation $ 9,656  
Recognized weighted average period (in years) 1 year 9 months 18 days