Shelf Registration and At-the-Market Offering	12 Months Ended
Dec. 31, 2021
Shelf Registration And At The Market Offering [Abstract]
Shelf Registration and At-the-Market Offering	8. Shelf Registration and At-the-Market Offering On March 14, 2019, the Company filed a shelf registration statement on Form S-3 with the SEC, which was declared effective by the SEC on May 10, 2019 and enables the Company to offer its common stock, preferred stock, debt securities, warrants, subscription rights and units having an aggregate offering price of up to $50,000. As part of this shelf registration, the Company entered into an equity distribution agreement with JMP Securities, pursuant to which the Company could offer and sell shares of its common stock having an aggregate offering price of up to $13,000 through an at-the-market offering program administered by JMP Securities. The Company was not required to sell any securities under this offering program. JMP Securities was entitled to compensation of up to 5.0% of the gross proceeds from sales of the Company’s common stock pursuant to the equity distribution agreement. For the year ended December 31, 2020, the Company sold 2,726 shares of its common stock under this equity distribution agreement and received proceeds of $7,500, net of offering costs of $463, at a weighted average sales price of $2.92 per share. For the year ended December 31, 2019, the Company sold 658 shares of its common stock under this equity distribution agreement and received proceeds of $1,643, net of offering costs of $210, at a weighted average sales price of $2.82 per share. During February 2021, the Company sold an additional 1,186 shares of its common stock under the equity distribution agreement and received proceeds of $3,025, net of offering costs of $157, at a weighted average sales price of $2.68 per share. There are currently no additional amounts available to be sold under this equity distribution agreement. On July 15, 2021, the Company increased the size of the remaining $37,000 available on the Initial Registration Statement by an additional $3,000 allowing it to offer securities with an aggregate gross sales price of up to $40,000. The Company also entered into a new equity distribution agreement with JMP Securities (the “July 2021 equity distribution agreement”) under which it could sell shares of its common stock up to a gross aggregate sales price of $40,000 through an at-the-market offering program administered by JMP Securities. JMP Securities was entitled to fees of 3% of the gross proceeds from sales of the Company’s common stock under this July 2021 equity distribution agreement. In July 2021 the Company sold 4,316 shares of its common stock under the July 2021 equity distribution agreement and received proceeds of $38,800, net of $1,200 in fees to JMP Securities, at a weighted average sales price of $9.27 per share, which resulted in the Company exhausting the amounts available for sale under the 2021 equity distribution agreement. On August 3, 2021, the Company filed a new shelf registration statement on Form S-3 with the SEC (the “2021 Registration Statement”), which was declared effective by the SEC on August 19, 2021 and provides that the Company may offer its common stock, preferred stock, debt securities, warrants, subscription rights and units having an aggregate offering price of up to $100,000. As part of this 2021 Registration Statement, the Company entered into a third equity distribution agreement with JMP Securities and established a new $50,000 “at-the-market” securities offering facility, pursuant to which, the Company may be able to issue and sell shares of the Company common stock. The Company has not yet sold any shares under this August 2021 equity distribution agreement and no assurances can be provided as to if or when the Company may be able to sell any shares or the terms of any such sales. In accordance with the SEC’s Instruction I.B.6 of Registration Statement on Form S-3, the Company is adjusting the maximum aggregate market value of the securities that may be sold pursuant to this current "at-the-market" securities offering facility from $50,000 to approximately $22,800 based on the estimated market capitalization of the Company on the date the Company files this Annual Report until such time when the Company is eligible to conduct such offering in accordance with Instruction I.B.1 of the Registration Statement on Form S-3.

Shelf Registration and At-the-Market Offering

12 Months Ended

Dec. 31, 2021

Shelf Registration And At The Market Offering [Abstract]

Shelf Registration and At-the-Market Offering

8. Shelf Registration and At-the-Market Offering

On March 14, 2019, the Company filed a shelf registration statement on Form S-3 with the SEC, which was declared effective by the SEC on May 10, 2019 and enables the Company to offer its common stock, preferred stock, debt securities, warrants, subscription rights and units having an aggregate offering price of up to $50,000. As part of this shelf registration, the Company entered into an equity distribution agreement with JMP Securities, pursuant to which the Company could offer and sell shares of its common stock having an aggregate offering price of up to $13,000 through an at-the-market offering program administered by JMP Securities. The Company was not required to sell any securities under this offering program. JMP Securities was entitled to compensation of up to 5.0% of the gross proceeds from sales of the Company’s common stock pursuant to the equity distribution agreement.

For the year ended December 31, 2020, the Company sold 2,726 shares of its common stock under this equity distribution agreement and received proceeds of $7,500, net of offering costs of $463, at a weighted average sales price of $2.92 per share. For the year ended December 31, 2019, the Company sold 658 shares of its common stock under this equity distribution agreement and received proceeds of $1,643, net of offering costs of $210, at a weighted average sales price of $2.82 per share. During February 2021, the Company sold an additional 1,186 shares of its common stock under the equity distribution agreement and received proceeds of $3,025, net of offering costs of $157, at a weighted average sales price of $2.68 per share. There are currently no additional amounts available to be sold under this equity distribution agreement.

On July 15, 2021, the Company increased the size of the remaining $37,000 available on the Initial Registration Statement by an additional $3,000 allowing it to offer securities with an aggregate gross sales price of up to $40,000. The Company also entered into a new equity distribution agreement with JMP Securities (the “July 2021 equity distribution agreement”) under which it could sell shares of its common stock up to a gross aggregate sales price of $40,000 through an at-the-market offering program administered by JMP Securities. JMP Securities was entitled to fees of 3% of the gross proceeds from sales of the Company’s common stock under this July 2021 equity distribution agreement. In July 2021 the Company sold 4,316 shares of its common stock under the July 2021 equity distribution agreement and received proceeds of $38,800, net of $1,200 in fees to JMP Securities, at a weighted average sales price of $9.27 per share, which resulted in the Company exhausting the amounts available for sale under the 2021 equity distribution agreement.

On August 3, 2021, the Company filed a new shelf registration statement on Form S-3 with the SEC (the “2021 Registration Statement”), which was declared effective by the SEC on August 19, 2021 and provides that the Company may offer its common stock, preferred stock, debt securities, warrants, subscription rights and units having an aggregate offering price of up to $100,000. As part of this 2021 Registration Statement, the Company entered into a third equity distribution agreement with JMP Securities and established a new $50,000 “at-the-market” securities offering facility, pursuant to which, the Company may be able to issue and sell shares of the Company common stock. The Company has not yet sold any shares under this August 2021 equity distribution agreement and no assurances can be provided as to if or when the Company may be able to sell any shares or the terms of any such sales. In accordance with the SEC’s Instruction I.B.6 of Registration Statement on Form S-3, the Company is adjusting the maximum aggregate market value of the securities that may be sold pursuant to this current "at-the-market" securities offering facility from $50,000 to approximately $22,800 based on the estimated market capitalization of the Company on the date the Company files this Annual Report until such time when the Company is eligible to conduct such offering in accordance with Instruction I.B.1 of the Registration Statement on Form S-3.