Stock-Based Compensation Expense (Tables)

9 Months Ended

Sep. 30, 2020

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,
	2020		2019		2020		2019
Cost of sales	$	336	$	346	$	1,022	$	953
Research and development		304		277		851		750
Selling, general and administrative		3,423		2,003		8,395		5,212
Stock-based compensation expense before taxes	$	4,063	$	2,626	$	10,268	$	6,915

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,
	2020	2019
Risk-free interest rate	0.29% - 1.67%	1.39% - 2.56%
Expected option term	4.0 - 5.0 years	3.0 - 5.0 years
Expected dividend yield	—	—
Expected price volatility	38.65% - 45.12%	28.66% - 35.79%

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,
	2020
Risk-free interest rate	1.1% - 1.3%
Performance period	0.8 - 2.8 years
Expected dividend yield	—
Expected price volatility	40.2% - 56.1%