Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands | Common Stock [Member] | Additional Paid-in Capital [Member] | AOCI Attributable to Parent [Member] | Retained Earnings [Member] | Total |
Beginning balance, value at Dec. 31, 2022 | $ 24 | $ 203,585 | | $ (183,295) | $ 20,314 |
Beginning balance, shares at Dec. 31, 2022 | 23,973 | | | | |
Stock-based compensation | | 927 | | | 927 |
Stock-based compensation, shares | 297 | | | | |
Stock option exercise | | 39 | | | 39 |
Stock option exercise, shares | 10 | | | | |
At-the-market sale of stock, net of commissions and expenses | | 274 | | | 274 |
At-the-market sale of stock, net of commissions and expenses, shares | 50 | | | | |
Net loss | | | | (5,019) | (5,019) |
Unrealized gain (loss) on available-for-sale securities | | | (2) | | (2) |
Ending balance, value at Mar. 31, 2023 | $ 24 | 204,825 | (2) | (188,314) | 16,533 |
Ending balance, shares at Mar. 31, 2023 | 24,330 | | | | |
Beginning balance, value at Dec. 31, 2022 | $ 24 | 203,585 | | (183,295) | 20,314 |
Beginning balance, shares at Dec. 31, 2022 | 23,973 | | | | |
Net loss | | | | | (10,171) |
Unrealized gain (loss) on available-for-sale securities | | | | | (2) |
Ending balance, value at Jun. 30, 2023 | $ 26 | 216,681 | (2) | (193,466) | 23,239 |
Ending balance, shares at Jun. 30, 2023 | 25,770 | | | | |
Beginning balance, value at Mar. 31, 2023 | $ 24 | 204,825 | (2) | (188,314) | 16,533 |
Beginning balance, shares at Mar. 31, 2023 | 24,330 | | | | |
Stock-based compensation | | 1,030 | | | 1,030 |
Stock-based compensation, shares | 60 | | | | |
Stock option exercise | | 39 | | | 39 |
Stock option exercise, shares | 10 | | | | |
At-the-market sale of stock, net of commissions and expenses | $ 2 | 10,787 | | | 10,789 |
At-the-market sale of stock, net of commissions and expenses, shares | 1,370 | | | | |
Net loss | | | | (5,152) | (5,152) |
Unrealized gain (loss) on available-for-sale securities | | | | | 0 |
Ending balance, value at Jun. 30, 2023 | $ 26 | 216,681 | (2) | (193,466) | 23,239 |
Ending balance, shares at Jun. 30, 2023 | 25,770 | | | | |
Beginning balance, value at Dec. 31, 2023 | $ 26 | 221,229 | | (203,085) | 18,170 |
Beginning balance, shares at Dec. 31, 2023 | 26,107 | | | | |
Stock-based compensation | | 1,024 | | | 1,024 |
Stock-based compensation, shares | 275 | | | | |
Stock option exercise | | 86 | | | 86 |
Stock option exercise, shares | 13 | | | | |
Forfeiture of restricted stock issuance | | | | | |
Forfeiture of restricted stock issuance, shares | (20) | | | | |
At-the-market sale of stock, net of commissions and expenses | $ 1 | 3,949 | | | 3,950 |
At-the-market sale of stock, net of commissions and expenses, shares | 510 | | | | |
Net loss | | | | (4,822) | (4,822) |
Unrealized gain (loss) on available-for-sale securities | | | (1) | | (1) |
Ending balance, value at Mar. 31, 2024 | $ 27 | 226,288 | (1) | (207,907) | 18,407 |
Ending balance, shares at Mar. 31, 2024 | 26,885 | | | | |
Beginning balance, value at Dec. 31, 2023 | $ 26 | 221,229 | | (203,085) | 18,170 |
Beginning balance, shares at Dec. 31, 2023 | 26,107 | | | | |
Net loss | | | | | (9,183) |
Unrealized gain (loss) on available-for-sale securities | | | | | (7) |
Ending balance, value at Jun. 30, 2024 | $ 28 | 229,726 | (7) | (212,268) | 17,479 |
Ending balance, shares at Jun. 30, 2024 | 27,610 | | | | |
Beginning balance, value at Mar. 31, 2024 | $ 27 | 226,288 | (1) | (207,907) | 18,407 |
Beginning balance, shares at Mar. 31, 2024 | 26,885 | | | | |
Stock-based compensation | | 987 | | | 987 |
Stock-based compensation, shares | 65 | | | | |
Forfeiture of restricted stock issuance | | | | | |
Forfeiture of restricted stock issuance, shares | (11) | | | | |
At-the-market sale of stock, net of commissions and expenses | $ 1 | 2,441 | | | 2,442 |
At-the-market sale of stock, net of commissions and expenses, shares | 669 | | | | |
Other sale | | 10 | | | 10 |
Other sale, shares | 2 | | | | |
Net loss | | | | (4,361) | (4,361) |
Unrealized gain (loss) on available-for-sale securities | | | (6) | | (6) |
Ending balance, value at Jun. 30, 2024 | $ 28 | $ 229,726 | $ (7) | $ (212,268) | $ 17,479 |
Ending balance, shares at Jun. 30, 2024 | 27,610 | | | | |