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Common Stock and Warrants - Additional Information (Details) $ / shares in Units, $ / shares in Units, $ in Millions |  |  |  |  |  |  |  | 1 Months Ended | 6 Months Ended |  |  |
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Jun. 30, 2021 USD ($) $ / shares shares | Jun. 30, 2021 CAD ($) shares | Feb. 01, 2021 USD ($) $ / shares shares | Oct. 26, 2020 USD ($) $ / shares shares | Mar. 20, 2020 USD ($) $ / shares shares | Jan. 27, 2020 USD ($) | Apr. 24, 2018 shares | Apr. 24, 2018 USD ($) shares | Apr. 13, 2018 USD ($) $ / shares shares | Apr. 30, 2021 shares | Mar. 31, 2020 USD ($) | Jun. 30, 2021 USD ($) $ / shares shares | Jun. 30, 2020 USD ($) $ / shares shares | Dec. 31, 2020 $ / shares shares | Dec. 31, 2019 USD ($) | Apr. 13, 2018 $ / shares shares
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock, shares authorized | 150,000,000 |  |  |  |  |  |  |  |  |  |  | 150,000,000 |  | 150,000,000 |  |
Common stock, par value | $ / shares | $ 0.001 |  |  |  |  |  |  |  |  |  |  | $ 0.001 |  | $ 0.001 |  |
Preferred stock, shares authorized | 10,000,000 |  |  |  |  |  |  |  |  |  |  | 10,000,000 |  | 10,000,000 |  |
Preferred stock, par value | $ / shares | $ 0.001 |  |  |  |  |  |  |  |  |  |  | $ 0.001 |  | $ 0.001 |  |
Common share, voting rights |  |  |  |  |  |  |  |  |  |  |  | one vote per share |  |  |  |
Common share, dividends declared | $ |  |  |  |  |  |  |  |  |  |  |  | $ 0 |  |  |  |
Gross proceeds from issuance of common stock | $ |  |  |  |  |  |  |  |  |  |  |  | 11,037,000 | $ 7,233,000 |  |  |
Warrants liability | $ | $ 0 |  |  |  |  |  |  |  |  |  |  | 0 | $ 1,000 |  | $ 5,000 |
Warrants Outstanding | $ | $ 0 |  |  |  |  |  |  |  |  |  |  | $ 0 |  |  |  |
April 2018 Offering |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Warrants to purchase number of common stock, shares |  |  |  |  |  |  |  |  | 61,197 |  |  |  |  |  |  | 61,197
Price per share | $ / shares |  |  |  |  |  |  |  |  | $ 261.45 |  |  |  |  |  |  |
Net proceeds from offering | $ |  |  |  |  |  |  |  | $ 16,300,000 |  |  |  |  |  |  |  |
Fair value of warrants at issuance | $ |  |  |  |  |  |  |  |  | $ 7,400,000 |  |  |  |  |  |  |
Warrant exercisable price per share | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 428.75
Warrants expiration date |  |  |  |  |  |  |  |  | Apr. 10, 2021 |  |  |  |  |  |  |
Number of common stock converted by each warrant |  |  |  |  |  |  |  |  | 1 |  |  |  |  |  |  | 1
Class of warrants exercised | 2,025 | 2,025 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from the exercise of warrants | $ |  | $ 0.9 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Class of warrants expired |  |  |  |  |  |  |  |  |  | 68,351 |  |  |  |  |  |
April 2018 Offering | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issued |  |  |  |  |  |  |  |  | 61,197 |  |  |  |  |  |  |
Over-Allotment Option |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Warrants to purchase number of common stock, shares |  |  |  |  |  |  | 9,179 | 9,179 |  |  |  |  |  |  |  |
Price per share | $ / shares |  |  | $ 18.525 |  |  |  |  |  |  |  |  |  |  |  |  |
Over-Allotment Option | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issued |  |  | 29,797 |  |  |  | 9,179 |  |  |  |  |  |  |  |  |
2020 ATM |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Price per share | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  | $ 21.68 |  |  |
Gross proceeds from issuance of common stock | $ |  |  |  |  |  |  |  |  |  |  |  |  | $ 5,000,000.0 |  |  |
Offering expenses incurred | $ |  |  |  |  |  |  |  |  |  |  |  |  | $ 181,000 |  |  |
2020 ATM | Form S3 Shelf Registration |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate offering amount | $ |  |  |  |  |  | $ 11,340,000 |  |  |  |  | $ 9,150,000 |  |  |  |  |
2020 ATM | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issued |  |  |  |  |  |  |  |  |  |  |  |  | 2 |  |  |
March 2020 Offering |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Warrants to purchase number of common stock, shares |  |  |  |  | 178,776 |  |  |  |  |  |  |  |  |  |  |
Price per share | $ / shares |  |  |  |  | $ 12.25 |  |  |  |  |  |  |  |  |  |  |
Fair value of warrants at issuance | $ |  |  |  |  | $ 800,000 |  |  |  |  |  |  |  |  |  |  |
Warrant exercisable price per share | $ / shares |  |  |  |  | $ 16.10 |  |  |  |  |  |  |  |  |  |  |
Number of common stock converted by each warrant |  |  |  |  | 1 |  |  |  |  |  |  |  |  |  |  |
Class of warrants exercised | 81,633 | 81,633 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from the exercise of warrants | $ | $ 1,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gross proceeds from issuance of common stock | $ |  |  |  |  | $ 2,200,000 |  |  |  |  |  |  |  |  |  |  |
Underwriting discounts and commissions paid | $ |  |  |  |  | $ 300,000 |  |  |  |  |  |  |  |  |  |  |
Warrants expiration date |  |  |  |  | Mar. 20, 2025 |  |  |  |  |  |  |  |  |  |  |
March 2020 Offering | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issued |  |  |  |  | 178,776 |  |  |  |  |  |  |  |  |  |  |
October 2020 Offering |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issued |  |  |  | 187,646 |  |  |  |  |  |  |  |  |  |  |  |
Warrants to purchase number of common stock, shares |  |  |  | 93,817 |  |  |  |  |  |  |  |  |  |  |  |
Price per share | $ / shares |  |  |  | $ 18.20 |  |  |  |  |  |  |  |  |  |  |  |
Fair value of warrants at issuance | $ |  |  |  | $ 600,000 |  |  |  |  |  |  |  |  |  |  |  |
Warrant exercisable price per share | $ / shares |  |  |  | $ 15.82 |  |  |  |  |  |  |  |  |  |  |  |
Gross proceeds from issuance of common stock | $ |  |  |  | $ 3,400,000 |  |  |  |  |  |  |  |  |  |  |  |
Share issuance cost including placement agent fees | $ |  |  |  | $ 300,000 |  |  |  |  |  |  |  |  |  |  |  |
Warrants expiration period |  |  |  | 3 years |  |  |  |  |  |  |  |  |  |  |  |
Percentage of right to participate subsequent financing |  |  |  | 30.00% |  |  |  |  |  |  |  |  |  |  |  |
October 2020 Offering | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subscription to participate subsequent financing | $ |  |  |  | $ 250,000 |  |  |  |  |  |  |  |  |  |  |  |
October 2020 Offering | Officer, Affiliates of an Officer and Director |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Price per share | $ / shares |  |  |  | $ 18.354 |  |  |  |  |  |  |  |  |  |  |  |
Warrant exercisable price per share | $ / shares |  |  |  | $ 16.1665 |  |  |  |  |  |  |  |  |  |  |  |
October 2020 Offering | Placement Agent |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issued |  |  |  | 961 |  |  |  |  |  |  |  |  |  |  |  |
Price per share | $ / shares |  |  |  | $ 19.775 |  |  |  |  |  |  |  |  |  |  |  |
October 2020 Offering | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of common stock converted by each warrant |  |  |  | 0.50 |  |  |  |  |  |  |  |  |  |  |  |
Common unit issued |  |  |  | 1 |  |  |  |  |  |  |  |  |  |  |  |
February 2021 Offering |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Warrants to purchase number of common stock, shares |  |  | 372,468 |  |  |  |  |  |  |  |  |  |  |  |  |
Price per share | $ / shares |  |  | $ 14.82 |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds from offering | $ |  |  | $ 9,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Fair value of warrants at issuance | $ |  |  | $ 2,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Warrant exercisable price per share | $ / shares |  |  | $ 16.302 |  |  |  |  |  |  |  |  |  |  |  |  |
Number of common stock converted by each warrant |  |  | 0.50 |  |  |  |  |  |  |  |  |  |  |  |  |
Class of warrants exercised | 262 | 262 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from the exercise of warrants | $ | $ 4,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Warrants expiration period |  |  | 5 years |  |  |  |  |  |  |  |  |  |  |  |  |
February 2021 Offering | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issued |  |  | 744,936 |  |  |  |  |  |  |  |  |  |  |  |  |
Class A Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule Of Stockholders Equity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock, shares authorized | 150,000,000 |  |  |  |  |  |  |  |  |  |  | 150,000,000 |  |  |  |
Common stock, par value | $ / shares | $ 0.001 |  |  |  |  |  |  |  |  |  |  | $ 0.001 |  |  |  |

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