Annual report pursuant to Section 13 and 15(d)

Income Taxes (Narrative) (Details)

v3.10.0.1
Income Taxes (Narrative) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Tax Disclosure [Line Items]        
Statutory income tax (benefit) expense 21.00% (34.00%) (34.00%)  
Gross deferred tax asset $ 47,922 $ 50,732    
Valuation allowance 42,122 45,811 $ 67,662 $ 64,486
Net deferred tax asset 5,800 4,921    
Deferred tax liabilities, gross 8,719 8,587    
Net change in valuation allowance $ (3,689) (21,851) 3,176  
Tax Cuts and Jobs Act of 2017, Percentage of Deferred Tax Asset Which Can be Used for Offset 80.00%      
Change in valuation allowance for deferred income taxes $ (3,486) (21,760) 3,176  
Net operating loss carryforwards for U.S. federal income tax purposes 141,067      
Research and experimentation credit carryforwards 3,791      
Unrecognized tax benefits that would impact effective tax rate 545 476    
Unrecognized tax benefits that reduce deferred tax assets 384 356    
Interest and penalty expense recognized 0 13 $ 183  
Total accrued interest and penalties $ 9 $ 6    
Minimum [Member]        
Income Tax Disclosure [Line Items]        
Foreign statutory tax rate, foreign operations 25.00%