Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Status of Stock Options Related to Stock Plans (Details)

v3.10.0.1
Employee Benefit Plans - Status of Stock Options Related to Stock Plans (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Options Outstanding Beginning Balance 228,000    
Options Outstanding Exercised (195,000)    
Options Outstanding Forfeited 0    
Options Outstanding Exercisable 33,000    
Options Outstanding Ending Balance 33,000 228,000  
Weighted Average Exercise Price Per Share, Beginning Balance $ 1.81    
Weighted Average Exercise Price Per Share, Exercised 1.81    
Weighted Average Exercise Price Per Share, Forfeited 0    
Weighted Average Exercise Price Per Share, Ending Balance 1.81 $ 1.81  
Weighted Average Exercise Price Per Share, Exercisable $ 1.81    
Weighted Average Remaining Contractual Term 3 months 18 days 1 year 3 months 18 days  
Weighted Average Remaining Contractual Term, Exercisable 3 months 18 days    
Aggregate Intrinsic Value, Beginning Balance $ 392 $ 3,787  
Aggregate Intrinsic Value, Exercisable 392    
Intrinsic value of stock options exercised $ 3,564 $ 425 $ 250
Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Exercise Price Per Share, Beginning Balance $ 1.81    
Exercise Price Per Share, Exercised 1.81    
Exercise Price Per Share, Forfeited 0    
Exercise Price Per Share, Ending Balance 1.81 $ 1.81  
Exercise Price Per Share, Exercisable 1.81    
Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Exercise Price Per Share, Beginning Balance 1.81    
Exercise Price Per Share, Exercised 1.81    
Exercise Price Per Share, Forfeited 0    
Exercise Price Per Share, Ending Balance 1.81 $ 1.81  
Exercise Price Per Share, Exercisable $ 1.81