Quarterly report pursuant to Section 13 or 15(d)

Balance Sheet Components - Additional Information (Details)

v3.7.0.1
Balance Sheet Components - Additional Information (Details)
 3 Months Ended 12 Months Ended
Mar. 31, 2017
USD ($)
Customer
Mar. 31, 2016
USD ($)
Customer
Dec. 31, 2016
USD ($)
Customer
Schedule Of Balance Sheet Components [Line Items]      
Unbilled Receivables $ 6,363,000   $ 7,484,000
Accounts receivable, net $ 30,927,000   30,828,000
Percentage of Non-US revenue invoiced in Euros 72.20% 68.30%  
Noncurrent inventories expected to be realized or consumed $ 309,000   314,000
Salvage value of expenditures for additions, improvements and replacements 0    
Repairs and maintenance expense 651,000 $ 687,000  
Depreciation and amortization 3,177,000 3,425,000  
Impairments of long-lived assets 0 0  
Impairment of finite lived intangible assets 0 0  
Amortization of intangible assets 27,000 23,000  
Construction in Process and Computer Software or Development Cost      
Schedule Of Balance Sheet Components [Line Items]      
Depreciation and amortization 0 $ 0  
Medicare      
Schedule Of Balance Sheet Components [Line Items]      
Accounts receivable, net 6,452,000   7,208,000
Customer Concentration Risk      
Schedule Of Balance Sheet Components [Line Items]      
Accounts receivable, net $ 10,090,000   $ 9,791,000
Sales Revenue, Net | Customer Concentration Risk      
Schedule Of Balance Sheet Components [Line Items]      
Number of customers | Customer 1 0  
Concentration risk, percentage 9.10% 19.50%  
Net Accounts Receivable | Customer Concentration Risk      
Schedule Of Balance Sheet Components [Line Items]      
Number of customers | Customer 1   1
Concentration risk, percentage 20.90%   23.40%
Sales Revenue, Services, Net | Customer Concentration Risk      
Schedule Of Balance Sheet Components [Line Items]      
Concentration risk, percentage 73.40% 82.20%  
Raw materials | Supplier Concentration Risk | Vendor one      
Schedule Of Balance Sheet Components [Line Items]      
Concentration risk, percentage 18.80% 14.10%  
Raw materials | Supplier Concentration Risk | Vendor two      
Schedule Of Balance Sheet Components [Line Items]      
Concentration risk, percentage 11.60% 11.80%  
Raw materials | Supplier Concentration Risk | Vendor three      
Schedule Of Balance Sheet Components [Line Items]      
Concentration risk, percentage 10.90% 7.10%