XML 14 R104.htm IDEA: XBRL DOCUMENT v3.20.1
Stockholders' Equity (Weighted Average Assumptions) (Details) - ESPP
3 Months Ended
Mar. 31, 2020
Dec. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Dividend yield 0.01%        
Expected volatility 48.63%        
Risk-free interest rate   1.56% 1.57% 1.57% 1.54%
Expected holding period (years)   1 year 9 months 6 months 3 months