Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands | Common Stock [Member] | Additional Paid-in Capital [Member] | Retained Earnings [Member] | Total |
Beginning balance, value at Dec. 31, 2020 | $ 22 | $ 187,463 | $ (150,140) | $ 37,345 |
Beginning balance, shares at Dec. 31, 2020 | 22,375 | | | |
Stock-based compensation | | 731 | | 731 |
Stock-based compensation, shares | 71 | | | |
At-the-market sale of stock, net of commissions and expenses | | 243 | | 243 |
At-the-market sale of stock, net of commissions and expenses, shares | 14 | | | |
Stock option exercise | $ 1 | 2,514 | | 2,515 |
Stock option exercise, shares | 398 | | | |
Warrant Exercise | | | | |
Warrant Exercise, shares | 223 | | | |
Forfeited restricted stock awards | | | | |
Forfeited restricted stock awards, shares | (54) | | | |
Net loss | | | (3,620) | (3,620) |
Ending balance, value at Mar. 31, 2021 | $ 23 | 190,951 | (153,760) | 37,214 |
Ending balance, shares at Mar. 31, 2021 | 23,027 | | | |
Stock-based compensation | | 847 | | 847 |
Stock-based compensation, shares | 18 | | | |
Stock option exercise | | 354 | | 354 |
Stock option exercise, shares | 59 | | | |
Net loss | | | (3,726) | (3,726) |
Ending balance, value at Jun. 30, 2021 | $ 23 | 192,152 | (157,486) | 34,689 |
Ending balance, shares at Jun. 30, 2021 | 23,104 | | | |
Beginning balance, value at Dec. 31, 2021 | $ 23 | 194,212 | (165,854) | 28,381 |
Beginning balance, shares at Dec. 31, 2021 | 23,207 | | | |
Stock-based compensation | | 726 | | 726 |
Stock-based compensation, shares | 161 | | | |
Stock option exercise | | 166 | | 166 |
Stock option exercise, shares | 25 | | | |
Net loss | | | (4,086) | (4,086) |
Ending balance, value at Mar. 31, 2022 | $ 23 | 195,104 | (169,940) | 25,187 |
Ending balance, shares at Mar. 31, 2022 | 23,393 | | | |
Beginning balance, value at Dec. 31, 2021 | $ 23 | 194,212 | (165,854) | 28,381 |
Beginning balance, shares at Dec. 31, 2021 | 23,207 | | | |
Ending balance, value at Jun. 30, 2022 | $ 23 | 196,148 | (174,421) | 21,750 |
Ending balance, shares at Jun. 30, 2022 | 23,457 | | | |
Beginning balance, value at Mar. 31, 2022 | $ 23 | 195,104 | (169,940) | 25,187 |
Beginning balance, shares at Mar. 31, 2022 | 23,393 | | | |
Stock-based compensation | | 859 | | 859 |
Stock-based compensation, shares | 33 | | | |
At-the-market sale of stock, net of commissions and expenses | | 185 | | 185 |
At-the-market sale of stock, net of commissions and expenses, shares | 31 | | | |
Net loss | | | (4,481) | (4,481) |
Ending balance, value at Jun. 30, 2022 | $ 23 | $ 196,148 | $ (174,421) | $ 21,750 |
Ending balance, shares at Jun. 30, 2022 | 23,457 | | | |