Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Unaudited) - USD ($) shares in Thousands, $ in Thousands | Total | Redeemable Convertible Preferred Stock | Common Stock | Additional Paid-In Capital | Accumulated Other Comprehensive Income (Loss) | Accumulated Deficit |
Beginning balance at Dec. 31, 2019 | $ (41,119) | | | $ 6,095 | $ (7) | $ (47,207) |
Beginning balance, Shares at Dec. 31, 2019 | | 7,597 | | | | |
Beginning balance at Dec. 31, 2019 | | $ 19,835 | | | | |
Beginning balance, Shares at Dec. 31, 2019 | | | 4,502 | | | |
Issuance of common stock upon exercise of stock options | 1 | | | 1 | | |
Issuance of common stock upon exercise of stock options, Shares | | | 4 | | | |
Repurchase of unvested restricted stock awards | | | (40) | | | |
Issuance of Series A redeemable convertible preferred stock | | $ 14,479 | | | | |
Issuance of Series A redeemable, Shares | | 4,237 | | | | |
Exercise of redeemable convertible preferred stock tranche liability | | $ 9,723 | | | | |
Stock-based compensation expense | 100 | | | 100 | | |
Other comprehensive income (loss) | (215) | | | | (215) | |
Net loss | (5,149) | | | | | (5,149) |
Ending balance at Mar. 31, 2020 | (46,382) | | | 6,196 | (222) | (52,356) |
Ending balance, Shares at Mar. 31, 2020 | | 11,834 | | | | |
Ending balance at Mar. 31, 2020 | | $ 44,037 | | | | |
Ending balance, Shares at Mar. 31, 2020 | | | 4,466 | | | |
Beginning balance at Dec. 31, 2019 | (41,119) | | | 6,095 | (7) | (47,207) |
Beginning balance, Shares at Dec. 31, 2019 | | 7,597 | | | | |
Beginning balance at Dec. 31, 2019 | | $ 19,835 | | | | |
Beginning balance, Shares at Dec. 31, 2019 | | | 4,502 | | | |
Net loss | (31,709) | | | | | |
Ending balance at Sep. 30, 2020 | (72,192) | $ 44,037 | | 6,810 | (86) | (78,916) |
Ending balance, Shares at Sep. 30, 2020 | | 11,834 | | | | |
Ending balance, Shares at Sep. 30, 2020 | | | 4,456 | | | |
Beginning balance at Mar. 31, 2020 | (46,382) | | | 6,196 | (222) | (52,356) |
Beginning balance, Shares at Mar. 31, 2020 | | 11,834 | | | | |
Beginning balance at Mar. 31, 2020 | | $ 44,037 | | | | |
Beginning balance, Shares at Mar. 31, 2020 | | | 4,466 | | | |
Stock-based compensation expense | 299 | | | 299 | | |
Other comprehensive income (loss) | 49 | | | | 49 | |
Net loss | (7,743) | | | | | (7,743) |
Ending balance at Jun. 30, 2020 | (53,777) | $ 44,037 | | 6,495 | (173) | (60,099) |
Ending balance, Shares at Jun. 30, 2020 | | 11,834 | | | | |
Ending balance, Shares at Jun. 30, 2020 | | | 4,466 | | | |
Repurchase of unvested restricted stock awards | | | (10) | | | |
Stock-based compensation expense | 315 | | | 315 | | |
Other comprehensive income (loss) | 87 | | | | 87 | |
Net loss | (18,817) | | | | | (18,817) |
Ending balance at Sep. 30, 2020 | (72,192) | $ 44,037 | | 6,810 | (86) | (78,916) |
Ending balance, Shares at Sep. 30, 2020 | | 11,834 | | | | |
Ending balance, Shares at Sep. 30, 2020 | | | 4,456 | | | |
Beginning balance at Dec. 31, 2020 | $ 334,622 | | $ 4 | 463,436 | 11 | (128,829) |
Beginning balance, Shares at Dec. 31, 2020 | 42,282 | | 42,282 | | | |
Issuance of common stock upon exercise of stock options and warrants and vesting of restricted stock units | $ 580 | | | 580 | | |
Issuance of common stock upon exercise of stock options and warrants and vesting of restricted stock units, shares | | | 100 | | | |
Stock-based compensation expense | 2,478 | | | 2,478 | | |
Other comprehensive income (loss) | 54 | | | | 54 | |
Net loss | (37,215) | | | | | (37,215) |
Ending balance at Mar. 31, 2021 | 300,519 | | $ 4 | 466,494 | 65 | (166,044) |
Ending balance, Shares at Mar. 31, 2021 | | | 42,382 | | | |
Beginning balance at Dec. 31, 2020 | $ 334,622 | | $ 4 | 463,436 | 11 | (128,829) |
Beginning balance, Shares at Dec. 31, 2020 | 42,282 | | 42,282 | | | |
Issuance of common stock upon exercise of stock options, Shares | 281 | | | | | |
Net loss | $ (110,482) | | | | | |
Ending balance at Sep. 30, 2021 | $ 269,780 | | $ 4 | 508,714 | 373 | (239,311) |
Ending balance, Shares at Sep. 30, 2021 | 44,830 | | 44,830 | | | |
Beginning balance at Mar. 31, 2021 | $ 300,519 | | $ 4 | 466,494 | 65 | (166,044) |
Beginning balance, Shares at Mar. 31, 2021 | | | 42,382 | | | |
Issuance of common stock upon exercise of stock options and warrants, issuance of common stock under Employee Stock Purchase Plan, and vesting of restricted stock units | 1,188 | | | 1,188 | | |
Issuance of common stock upon exercise of stock options and warrants, issuance of common stock under Employee Stock Purchase Plan, and vesting of restricted stock units, shares | | | 178 | | | |
Issuance of common stock under the at-the-market sales agreement,net of offering costs | 33,891 | | | 33,891 | | |
Issuance of common stock under the at-the-market sales agreement net of offering costs, shares | | | 2,216 | | | |
Stock-based compensation expense | 3,595 | | | 3,595 | | |
Other comprehensive income (loss) | 107 | | | | 107 | |
Net loss | (42,571) | | | | | (42,571) |
Ending balance at Jun. 30, 2021 | 296,729 | | $ 4 | 505,168 | 172 | (208,615) |
Ending balance, Shares at Jun. 30, 2021 | | | 44,776 | | | |
Issuance of common stock upon exercise of stock options and warrants and vesting of restricted stock units | 259 | | | 259 | | |
Issuance of common stock upon exercise of stock options and warrants and vesting of restricted stock units, shares | | | 54 | | | |
Stock-based compensation expense | 3,287 | | | 3,287 | | |
Other comprehensive income (loss) | 201 | | | | 201 | |
Net loss | (30,696) | | | | | (30,696) |
Ending balance at Sep. 30, 2021 | $ 269,780 | | $ 4 | $ 508,714 | $ 373 | $ (239,311) |
Ending balance, Shares at Sep. 30, 2021 | 44,830 | | 44,830 | | | |