Quarterly report pursuant to Section 13 or 15(d)

Balance Sheet Components - Additional Information (Details)

v3.20.1
Balance Sheet Components - Additional Information (Details)
3 Months Ended
Mar. 31, 2020
USD ($)
Customer
Mar. 31, 2019
USD ($)
Customer
Dec. 31, 2019
USD ($)
Schedule Of Balance Sheet Components [Line Items]      
Unbilled Receivables $ 596,000   $ 590,000
Accounts receivable, net $ 40,396,000   34,325,000
Percentage of Non-US revenue invoiced in Euros 68.70% 72.50%  
Transfer of inventory to rental equipment $ 368,000 $ 441,000  
Salvage value of expenditures for additions, improvements and replacements 0    
Repairs and maintenance expense 524,000 662,000  
Depreciation and amortization 2,220,000 2,466,000  
Impairments of long-lived assets 0 0  
Impairment of finite lived intangible assets 0 0  
Amortization of intangible assets 2,242,000 328,000  
Construction in Process and Computer Software or Development Cost      
Schedule Of Balance Sheet Components [Line Items]      
Depreciation and amortization 0 $ 0  
Other Noncurrent Assets      
Schedule Of Balance Sheet Components [Line Items]      
Noncurrent inventories expected to be realized or consumed 2,150,000   1,076,000
Customer Concentration Risk | Customer One      
Schedule Of Balance Sheet Components [Line Items]      
Accounts receivable, net 10,341,000   10,695,000
Customer Concentration Risk | Customer Two      
Schedule Of Balance Sheet Components [Line Items]      
Accounts receivable, net $ 8,978,000   $ 5,228,000
Sales Revenue, Net | Customer Concentration Risk      
Schedule Of Balance Sheet Components [Line Items]      
Number of customers | Customer 1 0  
Net Accounts Receivable | Customer Concentration Risk      
Schedule Of Balance Sheet Components [Line Items]      
Number of customers | Customer 2    
Raw materials | Supplier Concentration Risk | Vendor one      
Schedule Of Balance Sheet Components [Line Items]      
Concentration risk, percentage 23.60% 20.60%  
Raw materials | Supplier Concentration Risk | Vendor two      
Schedule Of Balance Sheet Components [Line Items]      
Concentration risk, percentage 15.20% 11.60%  
Raw materials | Supplier Concentration Risk | Vendor three      
Schedule Of Balance Sheet Components [Line Items]      
Concentration risk, percentage 9.40% 11.40%