Stock-Based Compensation - Stock-based Compensation Expense and Related Income Tax Benefit (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Employee and director stock-based compensation expense	$ 2,444	$ 2,291	$ 5,044	$ 4,594
Income tax benefit	416	500	882	1,006
Cost of sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Employee and director stock-based compensation expense	40	36	77	110
Research and development expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Employee and director stock-based compensation expense	318	288	631	524
Selling, general and administrative expenses | Employees
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Employee and director stock-based compensation expense	1,705	1,557	3,573	3,140
Selling, general and administrative expenses | Outside directors
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Employee and director stock-based compensation expense	$ 381	$ 410	$ 763	$ 820