Stock-Based Compensation Expense (Tables)

6 Months Ended

Jun. 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				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019
Cost of sales	$	347	$	355	$	686	$	607
Research and development		262		281		547		473
Selling, general and administrative		2,819		1,887		4,972		3,209
Stock-based compensation expense before taxes	$	3,428	$	2,523	$	6,205	$	4,289

Stock Options

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

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

	Six Months Ended
	June 30,
	2020	2019
Risk-free interest rate	0.52% - 1.67%	1.90% - 2.56%
Expected option term	4.0 - 5.0 years	3.0 - 5.0 years
Expected dividend yield	—	—
Expected price volatility	38.65% - 43.24%	28.66% - 33.69%

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

	Six Months Ended
	June 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%