Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2022

Equity [Abstract]

Summary of Series B Preferred Stock and Accretion of Dividends

The following table summarizes Series B convertible preferred stock and the accretion of dividend activity for the years ended December 31, 2022 and 2021 (in thousands):

	Year Ended December 31,
	2022		2021
Series B Convertible Preferred Stock:
Balance at beginning of period		24,117	$	22,969
Cumulative dividends on Series B convertible preferred stock		1,206		1,148
Balance at end of period	$	25,323	$	24,117
Number of Common Shares Issuable Upon Conversion:
Number of shares at beginning of period		6,029		5,742
Cumulative dividends on Series B convertible preferred stock		302		287
Number of shares at end of period		6,331		6,029

Summary of Outstanding Warrants Issued by Company

Below is the summary of outstanding warrants issued by the Company as of December 31, 2022:

Warrant Type	Number of Shares Issuable Upon Exercise		Weighted Average Exercise Price		Issue Date	Expiration Date
April 21 Funds Warrants		275,000	$	3.50	May 5, 2020	May 5, 2023

Summary of Common Stock Reserved for Future Issuance

Common Stock Reserved for Future Issuance

Common stock reserved for future issuance as of December 31, 2022 was as follows:

Exercise of outstanding stock options, vesting of restricted stock units ("RSU"), vesting of performance stock    units ("PSU"), and issuance of RSUs vested but not released	1,495,944
Employee Stock Purchase Plan	293,888
Shares of common stock available for grant under the 2011 Plan	530,537
Warrants to purchase common stock	275,000
Shares of common stock issuable upon conversion of Series B convertible preferred stock	7,541,449
Total	10,136,818