Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands | Total | Common Stock [Member] | Additional Paid-in Capital [Member] | Accumulated Other Comprehensive Income (Loss) [Member] | Accumulated Deficit [Member] |
Beginning balance at Dec. 31, 2018 | $ 34,124 | $ 245 | $ 270,509 | $ (16) | $ (236,614) |
Beginning balance, shares at Dec. 31, 2018 | | 24,456,120 | | | |
Stock-based compensation | 622 | | 622 | | |
Exercise of stock options | 3 | | 3 | | |
Exercise of stock options, shares | | 33,839 | | | |
Additional paid in capital on account of vested portion of restricted stock | 16 | | 16 | | |
Other comprehensive income (loss) | 18 | | | 18 | |
Net loss | (8,750) | | | | (8,750) |
Ending balance at Mar. 31, 2019 | 26,033 | $ 245 | 271,150 | 2 | (245,364) |
Ending balance, shares at Mar. 31, 2019 | | 24,489,959 | | | |
Beginning balance at Dec. 31, 2018 | 34,124 | $ 245 | 270,509 | (16) | (236,614) |
Beginning balance, shares at Dec. 31, 2018 | | 24,456,120 | | | |
Other comprehensive income (loss) | 65 | | | | |
Net loss | (24,273) | | | | |
Ending balance at Sep. 30, 2019 | 96,740 | $ 420 | 357,158 | 49 | (260,887) |
Ending balance, shares at Sep. 30, 2019 | | 42,005,465 | | | |
Beginning balance at Mar. 31, 2019 | 26,033 | $ 245 | 271,150 | 2 | (245,364) |
Beginning balance, shares at Mar. 31, 2019 | | 24,489,959 | | | |
Stock-based compensation | 627 | | 627 | | |
Exercise of stock options | 26 | | 26 | | |
Exercise of stock options, shares | | 24,110 | | | |
Issuance of common stock in follow-on offering, net | 32,233 | $ 73 | 32,160 | | |
Issuance of common stock in follow-on offering, net, shares | | 7,263,158 | | | |
Other comprehensive income (loss) | 50 | | | 50 | |
Net loss | (7,840) | | | | (7,840) |
Ending balance at Jun. 30, 2019 | 51,129 | $ 318 | 303,963 | 52 | (253,204) |
Ending balance, shares at Jun. 30, 2019 | | 31,777,227 | | | |
Stock-based compensation | 944 | | 944 | | |
Exercise of stock options | 10 | $ 1 | 9 | | |
Exercise of stock options, shares | | 61,811 | | | |
Issuance of common stock in follow-on offering, net | 52,343 | $ 101 | 52,242 | | |
Issuance of common stock in follow-on offering, net, shares | | 10,166,427 | | | |
Other comprehensive income (loss) | (3) | | | (3) | |
Net loss | (7,683) | | | | (7,683) |
Ending balance at Sep. 30, 2019 | 96,740 | $ 420 | 357,158 | 49 | (260,887) |
Ending balance, shares at Sep. 30, 2019 | | 42,005,465 | | | |
Beginning balance at Dec. 31, 2019 | 85,769 | $ 421 | 358,245 | 37 | (272,934) |
Beginning balance, shares at Dec. 31, 2019 | | 42,078,416 | | | |
Stock-based compensation | 1,162 | | 1,162 | | |
Exercise of stock options | 232 | $ 2 | 230 | | |
Exercise of stock options, shares | | 186,925 | | | |
Other comprehensive income (loss) | (34) | | | (34) | |
Net loss | (15,386) | | | | (15,386) |
Ending balance at Mar. 31, 2020 | 71,743 | $ 423 | 359,637 | 3 | (288,320) |
Ending balance, shares at Mar. 31, 2020 | | 42,265,341 | | | |
Beginning balance at Dec. 31, 2019 | 85,769 | $ 421 | 358,245 | 37 | (272,934) |
Beginning balance, shares at Dec. 31, 2019 | | 42,078,416 | | | |
Other comprehensive income (loss) | (31) | | | | |
Net loss | (54,971) | | | | |
Ending balance at Sep. 30, 2020 | 110,338 | $ 578 | 437,659 | 6 | (327,905) |
Ending balance, shares at Sep. 30, 2020 | | 57,804,095 | | | |
Beginning balance at Mar. 31, 2020 | 71,743 | $ 423 | 359,637 | 3 | (288,320) |
Beginning balance, shares at Mar. 31, 2020 | | 42,265,341 | | | |
Stock-based compensation | 1,335 | | 1,335 | | |
Exercise of stock options | 5 | | 5 | | |
Exercise of stock options, shares | | 3,591 | | | |
Other comprehensive income (loss) | 23 | | | 23 | |
Net loss | (21,128) | | | 0 | (21,128) |
Ending balance at Jun. 30, 2020 | 51,978 | $ 423 | 360,977 | 26 | (309,448) |
Ending balance, shares at Jun. 30, 2020 | | 42,268,932 | | | |
Stock-based compensation | 1,345 | | 1,345 | | |
Exercise of stock options | 13 | | 13 | | |
Exercise of stock options, shares | | 5,399 | | | |
Issuance of common stock and pre-funded warrants in follow-on offering, net | 75,479 | $ 151 | 75,328 | | |
Issuance of common stock and pre-funded warrants in follow-on offering, net , shares | | 15,125,000 | | | |
Issuance of common stock from cashless warrant exercise | 0 | $ 4 | (4) | | |
Issuance of common stock from cashless warrant exercise , shares | | 404,764 | | | |
Other comprehensive income (loss) | (20) | | | (20) | |
Net loss | (18,457) | | | | (18,457) |
Ending balance at Sep. 30, 2020 | $ 110,338 | $ 578 | $ 437,659 | $ 6 | $ (327,905) |
Ending balance, shares at Sep. 30, 2020 | | 57,804,095 | | | |