CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Revenue	$ 65,010	$ 103,171	$ 125,935	$ 200,572
Cost of goods sold	55,135	69,669	102,721	137,344
Gross profit	9,875	33,502	23,214	63,228
Operating expenses:
Research and development	15,410	13,689	28,508	25,573
Sales and marketing	3,362	4,279	7,227	7,938
General and administrative	7,398	8,803	14,692	15,592
Acquisition and asset sale related costs (recoveries)	(36)	120	127	132
Restructuring charges	22	0	22	0
Total operating expenses	26,156	26,891	50,576	49,235
Income (loss) from operations	(16,281)	6,611	(27,362)	13,993
Interest income	140	22	245	120
Interest expense	(220)	(301)	(447)	(679)
Other income (expense), net	(880)	(195)	263	1,003
Total interest and other income (expense), net	(960)	(474)	61	444
Income (loss) before income taxes	(17,241)	6,137	(27,301)	14,437
Income tax provision	(192)	(412)	(823)	(2,405)
Net income (loss)	$ (17,433)	$ 5,725	$ (28,124)	$ 12,032
Basic net income (loss) per share (in dollars per share)	$ (0.34)	$ 0.12	$ (0.55)	$ 0.25
Diluted net income (loss) per share (in dollars per share)	$ (0.34)	$ 0.11	$ (0.55)	$ 0.24
Weighted average shares used to compute basic net income (loss) per share (in shares)	51,634	49,077	51,178	48,846
Weighted average shares used to compute diluted net income (loss) per share (in shares)	51,634	51,661	51,178	51,124