Quarterly report pursuant to Section 13 or 15(d)

Shareholders' Equity - Additional Information (Details)

v3.20.2
Shareholders' Equity - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 6 Months Ended 9 Months Ended
Dec. 31, 2019
Nov. 08, 2016
Jun. 27, 2020
Jun. 29, 2019
Jun. 27, 2020
Jun. 29, 2019
Sep. 28, 2019
Dec. 28, 2019
Dec. 29, 2018
Shareholders Equity [Line Items]                  
Common stock, shares authorized (in shares)     10,000,000   10,000,000     10,000,000  
Common stock, issued shares (in shares)     1,993,578   1,993,578     1,919,048  
Common stock, outstanding shares (in shares)     1,993,578   1,993,578     1,919,048  
Stock issued new during period, shares             223,214    
Stock issued new during period, value             $ 1,000    
Share based compensation     $ 135   $ 511   $ 188    
Share based compensation amortized period         2021-09        
Options outstanding     78,400   78,400     44,400 100,900
Options granted         34,000        
Estimated future share-based compensation expense     $ 39   $ 39        
Share-based compensation award amortized period         2021-02        
Warrants outstanding     33,363   33,363     33,363  
Warrant exercise price     $ 3.40   $ 3.40     $ 3.40  
Warrant expiration date         Nov. 30, 2021        
Stock Options                  
Shareholders Equity [Line Items]                  
Stock options, exercisable     52,900   52,900        
Weighted average exercise price, exercisable     $ 11.51   $ 11.51        
Share-based compensation expense     $ 41 $ 60 $ 72 $ 120      
2016 Plan                  
Shareholders Equity [Line Items]                  
Options expiration date         Oct. 28, 2026        
Options authorized for issuance     400,000   400,000        
Options outstanding     38,000   38,000     4,000  
2016 Plan | Employees                  
Shareholders Equity [Line Items]                  
Options granted, vesting period         2 years        
2016 Plan | Non-Employee Directors                  
Shareholders Equity [Line Items]                  
Options granted, vesting period         6 months        
2011 Plan                  
Shareholders Equity [Line Items]                  
Options expiration date         May 12, 2021        
Options outstanding     40,400   40,400     40,400  
Additional awards to be granted after adoption of 2016 plan         0        
Energy Efficiency Investments LLC Securities Purchase Agreement | Notes Payable                  
Shareholders Equity [Line Items]                  
Debt issuance date   Nov. 08, 2016              
Debt interest rate   3.00%              
Energy Efficiency Investments LLC Securities Purchase Agreement | Notes Payable | Maximum                  
Shareholders Equity [Line Items]                  
Debt face amount   $ 7,732              
Common Stock | Energy Efficiency Investments LLC Securities Purchase Agreement                  
Shareholders Equity [Line Items]                  
Common shares, returned 122,257                
Contractor                  
Shareholders Equity [Line Items]                  
Stock issued for services, shares         74,530      
Stock issued for services, value         $ 376      
Articles of Incorporation                  
Shareholders Equity [Line Items]                  
Common stock, shares authorized (in shares)     10,000,000   10,000,000