Stock-Based Compensation - Schedule of Stock-based Compensation Expense Recorded in Operating Expenses (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]
Stock-based compensation in operating expenses	$ 636	$ 946	$ 1,727	$ 1,907
Selling, General and Administrative [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation in operating expenses	541	843	1,503	1,705
Research and Development [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation in operating expenses	$ 95	$ 103	$ 224	$ 202