| Condensed Consolidated Statements of Changes in Stockholders' Equity (Deficit) - USD ($) $ in Thousands | Total | Series A Preferred Stock [Member] | Series B Preferred Stock [Member] | Series C Preferred Stock [Member] | Preferred Stock [Member]  Series A Preferred Stock [Member] | Preferred Stock [Member]  Series B Preferred Stock [Member] | Preferred Stock [Member]  Series C Preferred Stock [Member] | Common Stock [Member] | Common Stock [Member]  Series A Preferred Stock [Member] | Common Stock [Member]  Series B Preferred Stock [Member] | Common Stock [Member]  Series C Preferred Stock [Member] | Additional Paid-in Capital [Member] | Additional Paid-in Capital [Member]  Series A Preferred Stock [Member] | Additional Paid-in Capital [Member]  Series B Preferred Stock [Member] | Additional Paid-in Capital [Member]  Series C Preferred Stock [Member] | Accumulated Other Comprehensive Loss [Member] | Accumulated Deficit [Member] | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Beginning balance at Dec. 31, 2019 | $ (18,655) | $ 52,809 | $ 35,228 | $ 65,222 | $ 2 | $ 7,354 | $ (628) | $ (178,642) | |||||||||||
| Beginning balance, shares at Dec. 31, 2019 | [1] | 21,615,723 | 8,306,818 | 12,804,176 | 17,602,594 | ||||||||||||||
| Exercise of stock options | 6 | 6 | |||||||||||||||||
| Exercise of stock options, shares | [1] | 4,351 | |||||||||||||||||
| Stock compensation expense | 1,451 | 1,451 | |||||||||||||||||
| Net loss | (22,340) | (22,340) | |||||||||||||||||
| Foreign currency translation adjustments | 30 | 30 | |||||||||||||||||
| Ending balance at Sep. 30, 2020 | (39,508) | $ 52,809 | $ 35,228 | $ 65,222 | $ 2 | 8,811 | (598) | (200,982) | |||||||||||
| Ending balance, shares at Sep. 30, 2020 | [1] | 21,615,723 | 8,306,818 | 12,804,176 | 17,606,945 | ||||||||||||||
| Beginning balance at Jun. 30, 2020 | (32,325) | $ 52,809 | $ 35,228 | $ 65,222 | $ 2 | 8,276 | (504) | (193,358) | |||||||||||
| Beginning balance, shares at Jun. 30, 2020 | [1] | 21,615,723 | 8,306,818 | 12,804,176 | 17,604,528 | ||||||||||||||
| Exercise of stock options | 4 | 4 | |||||||||||||||||
| Exercise of stock options, shares | [1] | 2,417 | |||||||||||||||||
| Stock compensation expense | 531 | 531 | |||||||||||||||||
| Net loss | (7,624) | (7,624) | |||||||||||||||||
| Foreign currency translation adjustments | (94) | (94) | |||||||||||||||||
| Ending balance at Sep. 30, 2020 | (39,508) | $ 52,809 | $ 35,228 | $ 65,222 | $ 2 | 8,811 | (598) | (200,982) | |||||||||||
| Ending balance, shares at Sep. 30, 2020 | [1] | 21,615,723 | 8,306,818 | 12,804,176 | 17,606,945 | ||||||||||||||
| Beginning balance at Dec. 31, 2020 | (48,736) | $ 52,809 | $ 35,228 | $ 65,222 | $ 2 | 10,131 | (982) | (211,146) | |||||||||||
| Beginning balance, shares at Dec. 31, 2020 | [1] | 21,615,723 | 8,306,818 | 12,804,176 | 17,664,015 | ||||||||||||||
| Exercise of stock options | 1,065 | 1,065 | |||||||||||||||||
| Exercise of stock options, shares | [1] | 799,901 | |||||||||||||||||
| Stock compensation expense | 6,600 | 6,600 | |||||||||||||||||
| Issuance of shares to FP Lenders (Note 6) | 22,868 | $ 1 | 22,868 | ||||||||||||||||
| Issuance of shares to FP Lenders (Note 6), shares | [1] | 2,468,492 | |||||||||||||||||
| Conversion of warrants to common stock | 308 | 308 | |||||||||||||||||
| Conversion of warrants to common stock, shares | [1] | 672,355 | |||||||||||||||||
| Conversion of convertible notes to common stock | 70,933 | $ 52,807 | $ 35,227 | $ 66,112 | $ (52,809) | $ (35,228) | $ (66,113) | $ 4 | $ 2 | $ 1 | $ 1 | 70,929 | |||||||
| Conversion of convertible notes to common stock, shares | [1] | 21,615,723 | 8,306,818 | 12,951,095 | (21,615,723) | (8,306,818) | (12,951,095) | 37,034,620 | |||||||||||
| Issuance of common stock upon the reverse recapitalization, net of issuance costs | 206,224 | $ 4 | 206,220 | ||||||||||||||||
| Issuance of common stock upon the reverse recapitalization, net of issuance costs, shares | [1] | 44,288,129 | |||||||||||||||||
| Contingent earnout liability upon closing of the merger | (78,395) | (78,395) | |||||||||||||||||
| Exercise of series C preferred warrants | $ 891 | $ 891 | |||||||||||||||||
| Exercise of series C preferred warrants, shares | [1] | 146,919 | |||||||||||||||||
| Net loss | (79,261) | (79,261) | |||||||||||||||||
| Foreign currency translation adjustments | 791 | 791 | |||||||||||||||||
| Ending balance at Sep. 30, 2021 | 103,289 | $ 0 | $ 0 | $ 0 | $ 15 | 393,872 | (191) | (290,407) | |||||||||||
| Ending balance, shares at Sep. 30, 2021 | [1] | 0 | 0 | 0 | 145,801,148 | ||||||||||||||
| Beginning balance at Jun. 30, 2021 | (80,699) | $ 52,809 | $ 35,228 | $ 66,113 | $ 2 | 23,370 | (515) | (257,706) | |||||||||||
| Beginning balance, shares at Jun. 30, 2021 | [1] | 21,615,723 | 8,306,818 | 12,951,095 | 19,212,323 | ||||||||||||||
| Exercise of stock options | 392 | 392 | |||||||||||||||||
| Exercise of stock options, shares | [1] | 229,316 | |||||||||||||||||
| Stock compensation expense | 2,099 | 2,099 | |||||||||||||||||
| Issuance of shares to FP Lenders (Note 6) | 14,804 | $ 1 | 14,803 | ||||||||||||||||
| Issuance of shares to FP Lenders (Note 6), shares | [1] | 1,490,769 | |||||||||||||||||
| Conversion of warrants to common stock | 308 | 308 | |||||||||||||||||
| Conversion of warrants to common stock, shares | [1] | 672,355 | |||||||||||||||||
| Conversion of convertible notes to common stock | 70,933 | $ (52,809) | $ (35,228) | $ (66,113) | $ 4 | $ 2 | $ 1 | $ 1 | 70,929 | $ 52,807 | $ 35,227 | $ 66,112 | |||||||
| Conversion of convertible notes to common stock, shares | [1] | (21,615,723) | (8,306,818) | (12,951,095) | 37,034,620 | 21,615,723 | 8,306,818 | 12,951,095 | |||||||||||
| Issuance of common stock upon the reverse recapitalization, net of issuance costs | 206,224 | $ 4 | 206,220 | ||||||||||||||||
| Issuance of common stock upon the reverse recapitalization, net of issuance costs, shares | [1] | 44,288,129 | |||||||||||||||||
| Contingent earnout liability upon closing of the merger | (78,395) | (78,395) | |||||||||||||||||
| Net loss | (32,701) | (32,701) | |||||||||||||||||
| Foreign currency translation adjustments | 324 | 324 | |||||||||||||||||
| Ending balance at Sep. 30, 2021 | $ 103,289 | $ 0 | $ 0 | $ 0 | $ 15 | $ 393,872 | $ (191) | $ (290,407) | |||||||||||
| Ending balance, shares at Sep. 30, 2021 | [1] | 0 | 0 | 0 | 145,801,148 | ||||||||||||||
| 
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