XML 65 R53.htm IDEA: XBRL DOCUMENT v3.20.2
Share-Based Payment Awards - Stock Option Activity Under Company's Equity Incentive Plan (Detail) - Equity Incentive Plans and Inducement Awards [Member]
9 Months Ended
Sep. 30, 2020
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Number of Options Outstanding, Beginning balance | shares 10,909,800
Number of Options, Granted | shares 3,971,397
Number of Options, Forfeited | shares (592,353)
Number of Options, Expired | shares (967,875)
Number of Options Outstanding, Ending balance | shares 13,320,969
Number of Options, Exercisable at September 30, 2020 | shares 6,369,131
Weighted Average Exercise Price Outstanding, Beginning balance | $ / shares $ 2.52
Weighted Average Exercise Price, Granted | $ / shares 1.24
Weighted Average Exercise Price, Forfeited | $ / shares 1.79
Weighted Average Exercise Price, Expired | $ / shares 3.44
Weighted Average Exercise Price Outstanding, Ending balance | $ / shares 2.10
Weighted Average Exercise Price, Exercisable at September 30, 2020 | $ / shares $ 2.60
Weighted Average Remaining Contractual Life, Outstanding at September 30, 2020 7 years 7 months 28 days
Weighted Average Remaining Contractual Life, Exercisable at September 30, 2020 6 years 9 months