Stock Option Plans (Tables)

6 Months Ended

Jun. 30, 2016

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock-Based Compensation

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2016		2015		2016		2015
	(in thousands)				(in thousands)
Research and development	$	272	$	178	$	558	$	383
Selling, general and administrative		1,384		1,390		2,712		2,594
Total stock-based compensation	$	1,656	$	1,568	$	3,270	$	2,977