Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2019

Share-based Payment Arrangement, Noncash Expense [Abstract]

Schedule of allocated non-cash, stock-based compensation expense for all employees

Total noncash, stock-based compensation expense for all of our employees is shown in the following table for the three and six months ended June 30, 2019 and 2018, respectively, and was assigned to the same expense categories as the base compensation for such employees (amounts in thousands):

	For the three months ended June 30,				For the six months ended June 30,
	2019		2018		2019		2018
Research and development expenses	$	81	$	150	$	242	$	341
Selling, general and administrative expenses	2,124		2,195		4,591		4,769
Total stock-based compensation	$	2,205	$	2,345	$	4,833	$	5,110