Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2020

Equity [Abstract]

Summary of Option Activity under 2018 Plan, 2013 Plan and 2010 Plan

Stock Plan Activity

A summary of option activity under the 2018 Plan, 2013 Plan, and 2010 Plan for the year ended December 31, 2020 is as follows:

	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in millions)
Options outstanding at December 31, 2019		1,313,475		$	12.28		8.7
Granted		141,000		$	3.56
Cancelled/forfeited		(214,121	)	$	13.04
Options outstanding at December 31, 2020		1,240,354		$	11.16		7.8	$	—
Options exercisable at December 31, 2020		490,345		$	15.36		6.6	$	—

Summary of Restricted Stock Unit Activity under 2018 Plan

A summary of restricted stock unit activity under the 2018 Plan for the year ended December 31, 2020 is as follows:

	Number of Shares			Weighted Average Grant Date Fair Value Per Share		Aggregate Intrinsic Value (in millions)
Non-vested outstanding at December 31, 2019		9,000		$	23.60
Vested/settled		(5,858	)
Cancelled/forfeited		(3,142	)
Non-vested outstanding at December 31, 2020		—		$	—	$	—