Stockholders' Equity - Company's Stock Option Activity (Details) - 2013 Equity Incentive Plan - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
OUTSTANDING OPTIONS
Outstanding at beginning of period	6,774,792
Options granted	2,206,050
Options exercised	(16,800)	0
Options forfeited	(246,131)
Outstanding at end of period	8,717,911		6,774,792
WEIGHTED-AVERAGE EXERCISE PRICE
Outstanding at beginning of period	$ 6.37
Options granted	2.61
Options exercised	2.01
Options forfeited	2.25
Outstanding at end of period	$ 5.54		$ 6.37
VESTED AND EXPECTED TO VEST
Outstanding options	8,576,011
Weighted-Average Exercise Price	$ 5.62
Weighted-Average Remaining Contractual Term	6 years 6 months
Aggregate Intrinsic Value (in thousands)	$ 315
ADDITIONAL DISCLOSURES
Outstanding options exercisable at end of period	4,928,465
Weighted-average exercise price exercisable at end of period	$ 8.05
Weighted-average contractual term outstanding	6 years 7 months 6 days		4 years 8 months 12 days
Weighted-average contractual term (years) exercisable	4 years 6 months
Aggregate intrinsic value (in thousands) outstanding at end of period	$ 336
Aggregate intrinsic value (in thousands) exercisable at end of period	$ 58

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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