Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues:
Total revenues	$ 787,309	$ 712,714	$ 695,908
Cost of revenues:
Total cost of revenues	414,979	394,077	378,823
Gross profit	372,330	318,637	317,085
Operating expenses:
Research and development	64,843	66,022	57,799
Selling, general, and administrative	263,095	241,470	237,881
Total operating expenses	327,938	307,492	295,680
Income from operations	44,392	11,145	21,405
Interest and other income (expense), net	(8,776)	(6,633)	(8,429)
Income before provision for income taxes	35,616	4,512	12,976
Provision for (benefit from) income taxes	(2,113)	(26,006)	3,220
Net income	$ 37,729	$ 30,518	$ 9,756
Net income per share:
Basic (in dollars per share)	$ 0.96	$ 0.81	$ 0.27
Diluted (in dollars per share)	$ 0.93	$ 0.79	$ 0.26
Weighted-average shares outstanding:
Basic (in shares)	39,242	37,483	36,156
Diluted (in shares)	40,559	38,712	36,864
Product revenues
Revenues:
Total revenues	$ 569,595	$ 510,201	$ 527,727
Cost of revenues:
Total cost of revenues	312,360	304,842	302,437
Service
Revenues:
Total revenues	217,714	202,513	168,181
Cost of revenues:
Total cost of revenues	$ 102,619	$ 89,235	$ 76,386