Quarterly report pursuant to Section 13 or 15(d)

Balance Sheet Components - Additional Information (Details)

v3.21.2
Balance Sheet Components - Additional Information (Details)
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2021
USD ($)
Jun. 30, 2020
USD ($)
Jun. 30, 2021
USD ($)
Customer
Jun. 30, 2020
USD ($)
Customer
Dec. 31, 2020
USD ($)
Customer
Schedule Of Balance Sheet Components [Line Items]          
Unbilled Receivables $ 785,000   $ 785,000   $ 459,000
Accounts receivable, net $ 36,946,000   $ 36,946,000   29,717,000
Percentage of Non-US revenue invoiced in Euros 67.40% 77.20% 72.40% 72.20%  
Transfer of inventory to rental equipment     $ 706,000 $ 1,193,000  
Salvage value of expenditures for additions, improvements and replacements $ 0   0    
Repairs and maintenance expense 739,000 $ 598,000 1,674,000 1,123,000  
Depreciation and amortization 3,038,000 2,230,000 5,872,000 4,450,000  
Impairments of long-lived assets     0 0  
Impairment of finite lived intangible assets     0   0
Goodwill impairment loss     0    
Construction in Process and Computer Software or Development Cost          
Schedule Of Balance Sheet Components [Line Items]          
Depreciation and amortization 0 $ 0 0 $ 0  
Other Noncurrent Assets          
Schedule Of Balance Sheet Components [Line Items]          
Noncurrent inventories expected to be realized or consumed 1,814,000   1,814,000   1,153,000
Customer Concentration Risk | Customer One          
Schedule Of Balance Sheet Components [Line Items]          
Accounts receivable, net 10,309,000   10,309,000   8,417,000
Customer Concentration Risk | Customer Two          
Schedule Of Balance Sheet Components [Line Items]          
Accounts receivable, net $ 7,800,000   $ 7,800,000   $ 7,044,000
Sales Revenue, Net | Customer Concentration Risk          
Schedule Of Balance Sheet Components [Line Items]          
Number of customers | Customer     1 1  
Net Accounts Receivable | Customer Concentration Risk          
Schedule Of Balance Sheet Components [Line Items]          
Number of customers | Customer     2   2
Raw materials | Supplier Concentration Risk | Vendor one          
Schedule Of Balance Sheet Components [Line Items]          
Concentration risk, percentage     16.30% 21.40%  
Raw materials | Supplier Concentration Risk | Vendor two          
Schedule Of Balance Sheet Components [Line Items]          
Concentration risk, percentage     14.10% 10.60%  
Raw materials | Supplier Concentration Risk | Vendor three          
Schedule Of Balance Sheet Components [Line Items]          
Concentration risk, percentage     11.70% 10.40%