XML 16 R6.htm IDEA: XBRL DOCUMENT v3.21.2
Statements of Stockholders' Equity (Unaudited) (Parenthetical) - shares
3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Statement of Stockholders' Equity [Abstract]      
Exercise of stock options, net of cashless exercise of shares 8,958 58,122 11,409