XML 47 R36.htm IDEA: XBRL DOCUMENT v3.20.2
Stockholders' Equity And Stock-Based Compensation (Schedule Of Fair Value Of Employee Stock Options) (Details)
3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Minimum [Member]        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Risk-free interest rate       1.90%
Maximum [Member]        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Risk-free interest rate       2.40%
Employee Stock Option [Member]        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Expected volatility 70.00% 70.00% 70.00% 70.00%
Dividend yield
Employee Stock Option [Member] | Minimum [Member]        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Expected term in years 5 years 3 months 18 days 5 years 3 months 18 days 5 years 3 months 18 days 4 months 24 days
Risk-free interest rate 0.40%   0.40% 1.90%
Employee Stock Option [Member] | Maximum [Member]        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Expected term in years 6 years 1 month 6 days 6 years 1 month 6 days 6 years 1 month 6 days 6 years 1 month 6 days
Risk-free interest rate 0.50%   0.50% 2.60%
2017 Employee Stock Purchase Plan [Member]        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Expected volatility 70.00% 70.00% 70.00% 70.00%
2017 Employee Stock Purchase Plan [Member] | Minimum [Member]        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Expected term in years 6 months 6 months 6 months 6 months
Risk-free interest rate 0.90% 2.50% 0.90% 2.50%
2017 Employee Stock Purchase Plan [Member] | Maximum [Member]        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Expected term in years 1 year 1 year 1 year 1 year
Risk-free interest rate 1.00% 2.60% 1.00% 2.60%