Annual report pursuant to Section 13 and 15(d)

Income Taxes (Narrative) (Details)

v3.8.0.1
Income Taxes (Narrative) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Income Tax Disclosure [Line Items]          
Tax Cuts and Jobs Act of 2017, Income Tax Benefit   $ 6,086      
Statutory income tax benefit   (34.00%) (34.00%) (34.00%)  
Tax Cuts and Jobs Act of 2017, Change in Tax Rate, Deferred Tax Asset, Income Tax Benefit   $ 1,067      
Tax Cuts and Jobs Act of 2017, Alternative Minimum Tax, Reclassification, Income Tax Benefit   507      
Tax Cuts and Jobs Act of 2017, Transition Tax, Tax Benefit, If Recognized   2,500      
Tax Cuts and Jobs Act of 2017, Valuation Allowance, Federal   4,512      
Tax Cuts and Jobs Act of 2017, Valuation Allowance, State, If Recognized   400      
Gross deferred tax asset   50,732 $ 75,416    
Valuation allowance   45,811 67,662 $ 64,486 $ 15,628
Net deferred tax asset   4,921 7,754    
Deferred tax liabilities, gross   8,587 16,720    
Net change in valuation allowance   (21,851) 3,176 48,858  
Tax Cuts and Jobs Act of 2017, Valuation Allowance Released   $ 4,512      
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   $ (21,760) 3,176 48,858  
Net operating loss carryforwards for U.S. federal income tax purposes   156,598      
Research and experimentation credit carryforwards   3,452      
Alternative minimum tax credit carryforwards   0      
Unrecognized tax benefits that would impact effective tax rate   476 1,135    
Unrecognized tax benefits that reduce deferred tax assets   356 327    
Interest and penalty expense recognized   13 183 $ 2  
Total accrued interest and penalties   6 $ 185    
Accounting Standards Update 2016-09 [Member]          
Income Tax Disclosure [Line Items]          
Gross deferred tax asset   92      
Valuation allowance   $ 92      
Scenario, Plan [Member]          
Income Tax Disclosure [Line Items]          
Statutory income tax benefit 21.00%        
Minimum [Member]          
Income Tax Disclosure [Line Items]          
Foreign statutory tax rate, foreign operations   25.00%