Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues:
Product	$ 135,103	$ 133,621	$ 362,089	$ 392,190
Services and other revenues	51,679	43,116	156,132	128,458
Total revenues	186,782	176,737	518,221	520,648
Cost of revenues:
Cost of product revenues	79,725	76,188	225,051	224,412
Cost of services and other revenues	22,204	19,041	66,150	56,766
Total cost of revenues	101,929	95,229	291,201	281,178
Gross profit	84,853	81,508	227,020	239,470
Operating expenses:
Research and development	16,414	15,264	50,128	42,896
Selling, general and administrative	58,725	61,316	186,818	189,912
Total operating expenses	75,139	76,580	236,946	232,808
Income (loss) from operations	9,714	4,928	(9,926)	6,662
Interest and other income (expense), net	(2,732)	(2,721)	(4,992)	(6,773)
Income (loss) before provision for income taxes	6,982	2,207	(14,918)	(111)
Provision for (benefit from) income taxes	751	224	(11,232)	(557)
Net income (loss)	$ 6,231	$ 1,983	$ (3,686)	$ 446
Net income (loss) per share:
Net income (loss) per share - basic (in dollars per share)	$ 0.17	$ 0.05	$ (0.10)	$ 0.01
Net income (loss) per share - diluted (in dollars per share)	$ 0.16	$ 0.05	$ (0.10)	$ 0.01
Weighted-average shares outstanding:
Weighted-average shares outstanding — basic (in shares)	37,698	36,332	37,266	36,020
Weighted-average shares outstanding — diluted (in shares)	38,973	37,079	37,266	36,695