Stock Option Plans (Tables)

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Stock Option Activity Under Stock Option Plan

Stock option activity under the Company's stock options plans for the years ending December 31, 2022 and 2021 were as follows:

(in thousands, except share and per share data)	Number of Shares			Weighted- Average Exercise Price		Weighted- Average Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding, December 31, 2020		6,840,719			3.81
Granted		9,380,438			2.62
Exercised		(363,109	)		2.86
Cancelled		(5,192,179	)		3.65
Outstanding, December 31, 2021		10,665,869		$	2.87
Granted		4,697,500			1.08
Exercised		(26,250	)		0.80
Cancelled		(4,928,497	)		3.34
Outstanding, December 31, 2022		10,408,622		$	1.84		8.69	$	3
Options exercisable, December 31, 2022		3,891,598		$	2.46		8.08	$	—
Options exercisable, December 31, 2021		4,410,312		$	3.85		7.53	$	—
Options available for future grant, December 31, 2022		15,460,088

Summary of Non-Vested Restricted Stock

A summary of the status of restricted stock as of December 31, 2022 and 2021 is as follows:

	Number of Shares			Weighted-Average Grant Date Fair Value
Unvested, December 31, 2020		786,280			3.08
Granted		1,601,224			2.60
Vested		(754,137	)		3.40
Cancelled		(434,787	)		3.45
Unvested, December 31, 2021		1,198,580		$	2.10
Granted		280,000			0.82
Vested		(306,617	)		2.28
Cancelled		(232,901	)		3.15
Unvested, December 31, 2022		939,062		$	1.40