Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue:
Revenue	$ 474,560	$ 342,958	$ 442,575
Cost of revenue:
Cost of revenue	275,976	198,806	262,939
Gross profit	198,584	144,152	179,636
Operating expenses:
Research and development	61,833	53,931	51,876
Sales and marketing	38,746	34,290	34,608
General and administrative	39,964	31,726	33,193
Total operating expenses	140,543	119,947	119,677
Income from operations	58,041	24,205	59,959
Other (expense) income:
Interest income	738	2,955	2,328
Interest expense	(5,211)	(5,155)	(5,110)
Other, net	2,318	(1,083)	(2,472)
Total other expense	(2,155)	(3,283)	(5,254)
Income before income taxes	55,886	20,922	54,705
Income tax provision	5,904	3,888	8,820
Net income	$ 49,982	$ 17,034	$ 45,885
Net income per share:
Basic	$ 1.50	$ 0.52	$ 1.42
Diluted	$ 1.46	$ 0.50	$ 1.35
Shares used in computing net income per share:
Basic weighted average common shares	33,257	32,559	32,286
Diluted weighted average common shares	34,128	33,828	34,002
Product
Revenue:
Revenue	$ 449,903	$ 319,505	$ 415,922
Cost of revenue:
Cost of revenue	252,390	175,732	236,446
Services
Revenue:
Revenue	24,657	23,453	26,653
Cost of revenue:
Cost of revenue	$ 23,586	$ 23,074	$ 26,493