Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Consolidated Statements of Operations
Net sales	$ 97,822	$ 157,779	$ 197,193	$ 316,353
Cost of sales	61,537	102,384	126,192	204,278
Gross profit	36,285	55,395	71,001	112,075
Operating expenses, net:
Research and development	22,922	24,930	46,262	49,250
Selling, general, and administrative	19,757	24,274	39,660	50,657
Amortization of intangible assets	4,243	10,386	8,460	23,918
Restructuring	616	2,917	2,046	5,612
Acquisition costs		1,316		2,657
Asset impairment		252,343		252,343
Other, net	(44)	443	(80)	286
Total operating expenses, net	47,494	316,609	96,348	384,723
Operating income (loss)	(11,209)	(261,214)	(25,347)	(272,648)
Interest income	1,284	819	2,529	1,443
Interest expense	(5,495)	(5,264)	(10,941)	(10,511)
Income (loss) before income taxes	(15,420)	(265,659)	(33,759)	(281,716)
Income tax expense (benefit)	145	(28,025)	336	(28,255)
Net income (loss)	$ (15,565)	$ (237,634)	$ (34,095)	$ (253,461)
Income (loss) per common share:
Basic (in dollars per share)	$ (0.33)	$ (5.02)	$ (0.72)	$ (5.35)
Diluted (in dollars per share)	$ (0.33)	$ (5.02)	$ (0.72)	$ (5.35)
Weighted average number of shares:
Basic (in shares)	47,112	47,311	47,145	47,332
Diluted (in shares)	47,112	47,311	47,145	47,332