Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation and Employee Benefit Plans - ESPP (Details 3)

v3.19.1
Stock-Based Compensation and Employee Benefit Plans - ESPP (Details 3) - $ / shares
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
ESPP [Member]    
Stock Issued During Period, Shares, Employee Stock Purchase Plans 0  
Employee Stock [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value $ 5.01 $ 6.51
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate 2.51% 1.39%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate 0.00% 0.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term 6 months 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate 38.82% 36.97%