Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Options Activity

The following is a summary of stock option activity during the six months ended June 30, 2021:

	Options Outstanding
	Number of Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (years)		Aggregate Intrinsic Value
Balance—January 1, 2021		1,570,728		$	9.09		7.71	$	12,756
Options granted		—		$	—		—	$	—
Options exercised		(978,495	)	$	9.01		—	$	—
Options cancelled		(29,705	)	$	9.23		—	$	—
Balance—June 30, 2021		562,528		$	9.21		7.31	$	3,049
Exercisable as of June 30, 2021		467,528		$	9.12		7.26	$	2,574
Vested and expected to vest as of June 30, 2021		562,528		$	9.21		7.31	$	3,049

Summary of Restricted Stock Award Activity

A summary of restricted stock award activity within the Company’s equity plans and changes for the six months ended June 30, 2021 is as follows:

Restricted Stock Awards	Shares			Weighted Average Grant- Date Fair Value
Nonvested at January 1, 2021		3,259,389		$	13.51
Granted		1,895,642		$	16.15
Vested		(1,460,312	)	$	15.68
Forfeited		(258,971	)	$	13.53
Nonvested at June 30, 2021		3,435,748		$	13.88

Summary of Total Stock-based Compensation Expense by Function

The following table summarizes the total stock-based compensation expense by function, including expense related to consultants, for the three and six months ended June 30, 2020 and 2021:

	Three Months Ended June 30,					Six Months Ended June 30,
	2020			2021		2020		2021
	(in thousands)					(in thousands)
Sales and distribution expenses	$	(579	)	$	1,569	$	1,013	$	2,524
Research and development expenses		1,179			1,221		2,452		2,104
General and administrative expenses		4,571			2,072		9,145		7,132
Total stock-based compensation expense	$	5,171		$	4,862	$	12,610	$	11,760