Annual report pursuant to Section 13 and 15(d)

Income Taxes (Details Textual)

v3.6.0.2
Income Taxes (Details Textual) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Income Tax Disclosure [Line Items]      
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount $ 4.4 $ 2.7 $ 0.5
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent 34.00%    
Stock Option Plan [Member]      
Income Tax Disclosure [Line Items]      
Operating Loss Carryforwards $ 12.4    
California Franchise Tax Board [Member]      
Income Tax Disclosure [Line Items]      
Operating Loss Carry Forwards Expiration Year 2035    
Operating Loss Carryforwards $ 124.4    
Domestic Tax Authority [Member]      
Income Tax Disclosure [Line Items]      
Operating Loss Carry Forwards Expiration Year 2035    
Operating Loss Carryforwards $ 247.7    
Domestic Tax Authority [Member] | Research Tax Credit Carryforward [Member]      
Income Tax Disclosure [Line Items]      
Operating Loss Carry Forwards Expiration Year 2035    
Tax Credit Carryforward, Amount $ 8.7    
State and Local Jurisdiction [Member] | Research Tax Credit Carryforward [Member]      
Income Tax Disclosure [Line Items]      
Tax Credit Carryforward, Amount $ 8.5