Warrants (Tables)

12 Months Ended

Dec. 31, 2020

Other Liabilities Disclosure [Abstract]

Schedule of Warrants Issued and Outstanding

The table below summarizes common stock warrants issued and outstanding at both December 31, 2020 and 2019:

Date			Number of Shares Underlying Warrants	Price per Share	Fair Value (in thousands)
Issuance	Expiration
3/1/2017	3/1/2027	[a]	1,388	$5.94	$	5	[b]
7/22/2013	7/22/2023	[a]	32,983	$9.10	122		[b]
11/26/2014	11/26/2024	[a]	6,680	$16.47	49		[b]
10/20/2015	10/20/2025	[a]	41,650	$16.47	396		[c]
11/9/2015	11/9/2025	[a]	25,709	$16.47	244		[c]
12/22/2016	12/22/2026	[a]	9,712	$10.03	45		[c]
			118,122		$	861

[a]    Common stock warrants will remain outstanding until the earlier of the expiration date or the date exercised by the holder.

[b]    Fair value at the date of issuance.

[c] Fair value at the date of conversion from redeemable convertible preferred stock to common stock warrants in conjunction with the IPO on October 16, 2018.