Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue:
Product	$ 387,124	$ 244,295	$ 278,875
Services	23,437	22,685	22,620
Total revenue	410,561	266,980	301,495
Cost of revenue:
Product	234,932	149,007	181,060
Services	25,382	18,375	18,729
Total cost of revenue	260,314	167,382	199,789
Gross profit	150,247	99,598	101,706
Operating expenses:
Research and development	43,071	34,402	32,586
Sales and marketing	28,532	23,839	23,325
General and administrative	30,802	24,452	25,059
Restructuring charges		282	18
Total operating expenses	102,405	82,975	80,988
Income from operations	47,842	16,623	20,718
Other (expense) income:
Interest income	714	238	64
Interest expense	(5,121)	(5,073)	(4,976)
Other, net	396	(764)	(601)
Total other expense	(4,011)	(5,599)	(5,513)
Income before income taxes	43,831	11,024	15,205
Income tax (benefit) provision	(83,128)	23	527
Net income	$ 126,959	$ 11,001	$ 14,678
Net income per share:
Basic (in dollars per share)	$ 4.11	$ 0.38	$ 0.51
Diluted (in dollars per share)	$ 3.80	$ 0.36	$ 0.49
Shares used in computing net income per share:
Basic weighted average common shares	30,866	29,195	28,595
Diluted weighted average common shares	33,436	30,947	30,229