Stock-Based Compensation Expense (Tables)

9 Months Ended

Sep. 30, 2021

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2021		2020		2021		2020
Cost of sales
Nonqualified stock options	$	383	$	336	$	1,019	$	1,022
Research and development
Nonqualified stock options		355		304		910		851
Selling, general and administrative
Nonqualified stock options		2,071		1,948		4,512		5,377
Performance-based restricted stock units		1,193		842		2,896		1,987
Restricted stock units		409		363		1,149		395
Cash-settled performance-based share-based awards ("Liability Awards")		446		270		1,103		636
Total selling, general and administrative		4,119		3,423		9,660		8,395
Stock-based compensation expense before taxes	$	4,857	$	4,063	$	11,589	$	10,268

Stock Options

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

	Nine Months Ended
	September 30,
	2021	2020
Risk-free interest rate	0.5% - 0.7%	0.3% - 1.7%
Expected option term	4.0 years	4.0 - 5.0 years
Expected dividend yield	—	—
Expected price volatility	46.3% - 46.7%	38.7% - 45.1%

Stock-Settled Performance-Based Restricted Stock Units

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

	Nine Months Ended
	September 30,
	2021	2020
Risk-free interest rate	0.1% - 0.3%	1.1% - 1.3%
Performance period	1.8 - 2.8 years	0.8 - 2.8 years
Expected dividend yield	—	—
Expected price volatility	43.7% - 49.3%	40.2% - 56.1%