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Revenue Recognition - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Jul. 28, 2018
Jul. 28, 2018
Apr. 28, 2018
Jan. 31, 2018
Disaggregation of Revenue [Line Items]        
Standard payment terms   30 days    
Contract liabilities and extended warranties $ 366,000 $ 366,000   $ 367,000
Revenue recognized   $ 403,000    
Contract costs, benefitial term   10 years    
Amortization of incremental direct costs 9,000 $ 18,000    
Deferred incremental direct costs net of accumulated amortization $ 967,000 $ 967,000   $ 832,000
Amortization period of contract costs 8 years 8 years    
Additional incremental direct costs which were deferred     $ 150,000  
Hardware [Member]        
Disaggregation of Revenue [Line Items]        
Products warranty period   12 months    
Maximum [Member] | Airborne Product [Member]        
Disaggregation of Revenue [Line Items]        
Products warranty period   5 years    
Maximum [Member] | Sales Revenue, Net [Member] | Customer Concentration Risk [Member]        
Disaggregation of Revenue [Line Items]        
Percentage of revenue satisfied for services   9.00%    
Minimum [Member] | Airborne Product [Member]        
Disaggregation of Revenue [Line Items]        
Products warranty period   4 years