Quarterly report pursuant to Section 13 or 15(d)

Stock Based Option Compensation and Restricted Stock Compensation (Details Textual)

v3.8.0.1
Stock Based Option Compensation and Restricted Stock Compensation (Details Textual) - USD ($)
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Share-based and Restricted Stock Compensation Expense [Abstract]    
Stock-based compensation expense included in operating expense $ 1,900,000 $ 1,492,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate 0.00%  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate 1.09%  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate 2.37%  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term 5 years  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value $ 10.83  
Share-based Compensation Arrangement by Share-based Payment Award, Option Grants in Period Weighted Average Grant Date Fair Value $ 10.83  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Exercise Price $ 13.72  
Stock Options [Member]    
Share-based and Restricted Stock Compensation Expense [Abstract]    
Stock options granted (in shares) 645,000 0
Stock-based compensation expense included in operating expense $ 1,900,000 $ 1,492,000
Restricted Stock [Member]    
Share-based and Restricted Stock Compensation Expense [Abstract]    
Stock-based compensation expense included in operating expense $ 172,000 $ 362,000