Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Total revenues	$ 204,267	$ 186,748	$ 575,559	$ 516,343
Cost of revenues:
Total cost of revenues	105,358	101,929	305,412	291,201
Gross profit	98,909	84,819	270,147	225,142
Operating expenses:
Research and development	15,805	16,414	47,854	50,128
Selling, general, and administrative	65,609	56,208	196,831	180,070
Total operating expenses	81,414	72,622	244,685	230,198
Income (loss) from operations	17,495	12,197	25,462	(5,056)
Interest and other income (expense), net	(2,837)	(2,732)	(6,462)	(4,992)
Income (loss) before provision for income taxes	14,658	9,465	19,000	(10,048)
Provision for (benefit from) income taxes	1,030	1,717	(3,936)	(9,341)
Net income (loss)	$ 13,628	$ 7,748	$ 22,936	$ (707)
Net income (loss) per share:
Net income (loss) per share - basic (in dollars per share)	$ 0.35	$ 0.21	$ 0.59	$ (0.02)
Net income (loss) per share - diluted (in dollars per share)	$ 0.33	$ 0.20	$ 0.57	$ (0.02)
Weighted-average shares outstanding:
Weighted-average shares outstanding — basic (in shares)	39,432	37,698	39,015	37,266
Weighted-average shares outstanding — diluted (in shares)	40,860	38,973	40,237	37,266
Product revenues
Revenues:
Total revenues	$ 149,709	$ 136,838	$ 415,004	$ 365,834
Cost of revenues:
Total cost of revenues	79,149	79,725	229,642	225,051
Services and other revenues
Revenues:
Total revenues	54,558	49,910	160,555	150,509
Cost of revenues:
Total cost of revenues	$ 26,209	$ 22,204	$ 75,770	$ 66,150