Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Options Activity

The following is a summary of stock options activity during the year-ended December 31, 2019:

	Options Outstanding
	Number of Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (years)		Aggregate Intrinsic Value
Balance—January 1, 2019		1,867,747		$	9.01		9.64	$	19,573,295
Options granted		195,975		$	9.49
Options exercised		(487	)	$	4.14			$	1,630
Options cancelled		(200,666	)	$	8.90
Balance—December 31, 2019		1,862,569		$	9.09		8.64	$	99,289
Exercisable as of December 31, 2019		777,147		$	8.69		8.21	$	93,775
Vested and expected to vest as of December 31, 2019		1,862,569		$	9.09		8.64	$	99,289

Summary of Weighted Average Assumptions Used in Black-Scholes Option-Pricing Model to Determine Grant Fair Value

The following are weighted-average assumptions used in the Black-Scholes option-pricing model to determine grant fair value:

	December 31, 2018			December 31, 2019
	Weighted- Average			Weighted- Average
Expected term (in years)		5.73			5.77
Volatility		55.06	%		66.72	%
Risk-free interest rate		2.59	%		1.76	%
Dividend Yield		0.000			0.000

Summary of Restricted Stock Activity

A summary of restricted stock activity within the Company’s equity plans and changes for the year-ended December 31, 2019, is as follows:

Restricted Stock Awards	Shares			Weighted Average Grant- Date Fair Value
Nonvested at January 1, 2019		—		$	—
Granted		2,719,633		$	18.52
Vested		—		$	—
Forfeited		(117,661	)	$	19.50
Nonvested at December 31, 2019		2,601,972		$	18.21

Summary of Total Stock-based Compensation Expense by Function

The following table summarizes the total stock-based compensation expense by function for the years-ended December 31, 2018 and 2019:

	Years-end December 31,
	2018		2019
	(in thousands)
Sales and distribution expenses	$	69	$	7,358
Research and development expenses		25		5,711
General and administrative expenses		525		21,612
Total stock-based compensation expense	$	619	$	34,681