Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues:
Total revenues	$ 217,413	$ 188,673	$ 419,930	$ 371,292
Cost of revenues:
Total cost of revenues	113,368	99,890	218,768	200,054
Gross profit	104,045	88,783	201,162	171,238
Operating expenses:
Research and development	16,848	15,512	32,926	32,049
Selling, general, and administrative	68,434	65,937	136,712	131,222
Total operating expenses	85,282	81,449	169,638	163,271
Income from operations	18,763	7,334	31,524	7,967
Interest and other income (expense), net	(1,629)	(896)	(3,039)	(3,625)
Income before provision for income taxes	17,134	6,438	28,485	4,342
Provision for (benefit from) income taxes	1,158	(150)	9,225	(4,966)
Net income	$ 15,976	$ 6,588	$ 19,260	$ 9,308
Net income per share:
Net income per share - basic (in dollars per share)	$ 0.39	$ 0.17	$ 0.47	$ 0.24
Net income per share - diluted (in dollars per share)	$ 0.37	$ 0.16	$ 0.45	$ 0.23
Weighted-average shares outstanding:
Weighted-average shares outstanding — basic (in shares)	41,371	38,970	41,033	38,804
Weighted-average shares outstanding — diluted (in shares)	42,945	40,000	42,646	39,854
Product revenues
Revenues:
Total revenues	$ 158,379	$ 134,636	$ 303,989	$ 265,295
Cost of revenues:
Total cost of revenues	84,583	75,076	163,394	150,493
Services and other revenues
Revenues:
Total revenues	59,034	54,037	115,941	105,997
Cost of revenues:
Total cost of revenues	$ 28,785	$ 24,814	$ 55,374	$ 49,561