Employee Equity-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2021

Share-based Payment Arrangement [Abstract]

Summary of Option Activity

The following table summarizes option activity under the Company's equity-based compensation plans for the nine months ended September 30, 2021:

	Number of Shares	Weighted Average Exercise Price per Share
Options Outstanding January 1, 2021	8,045,461	$	14.18
Granted	489,804	7.09
Forfeited	(269,712)	14.66
Exercised	(391,362)	3.72
Expired	(240,460)	19.03
Options Outstanding September 30, 2021	7,633,731	$	14.09

Weighted Average Inputs to Calculate Estimated Fair Value of Options Awarded

The table below summarizes the resulting weighted average inputs used to calculate the estimated fair value of options awarded for the three months ended September 30, 2021 and 2020:

	Three Months Ended September 30,
	2021			2020
Expected term (in years)	0.00			6.14
Volatility	—		%	62		%
Expected dividends	—			—
Risk free interest rates	—		%	0.42		%
Weighted average fair value	$	—		$	8.10

Summary Information for Outstanding and Exercisable Options

The following table shows summary information for outstanding options and options that are exercisable (vested) as of September 30, 2021:

	Options Outstanding		Options Exercisable
Number of options	7,633,731		5,063,626
Weighted average remaining contractual term (in years)	5.92		4.87
Weighted average exercise price	$	14.09	$	14.68
Weighted average fair value	$	8.78	$	9.11
Aggregate intrinsic value (in thousands)	$	1,933	$	1,929

Summary of RSU and Performance-based Award Activity

The following table summarizes RSU and performance-based award activity for the nine months ended September 30, 2021:

	Number of Shares	Weighted Average Grant Date Fair Value per Share
Outstanding January 1, 2021	526,414	$	11.17
Granted	2,678,948	11.28
Forfeited	(225,359)	11.80
Vested/released	(659,539)	12.23
Outstanding September 30, 2021	2,320,464	$	10.78

Summary of Compensation Expense

The table below summarizes equity-based compensation expense for the three and nine months ended September 30, 2021 and 2020 (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Cost of sales	$	82	$	119	$	257	$	249
Research and development	266		1,349		4,340		2,807
Sales, general and administrative	3,281		3,208		14,461		9,235
	$	3,629	$	4,676	$	19,058	$	12,291

The table below summarizes share-based compensation cost capitalized to inventory or inventory transferred to property and equipment (also referred to as instruments) for the three and nine months ended September 30, 2021 and 2020 (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Cost capitalized to inventory	$	77	$	61	$	319	$	199

The table below summarizes share-based compensation cost in connection with performance-based stock options for the nine months ended September 30, 2021 and 2020 (in thousands):

	Nine Months Ended September 30,
	2021		2020
Performance-based stock option expense	$	230	$	109

The table below summarizes share-based compensation cost in connection with performance-based RSUs for the nine months ended September 30, 2021, and 2020 (in thousands):

	Nine Months Ended September 30,
	2021		2020
Performance-based RSU expense	$	818	$	401