CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (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
Revenue:
Total revenue	$ 52,101	$ 68,722	$ 87,587	$ 157,796
Cost of revenue:
Total cost of revenue	12,796	19,321	23,785	46,440
Gross profit	39,305	49,401	63,802	111,356
Operating expenses:
Research and development	18,260	16,696	36,665	37,226
Selling, general and administrative	17,302	16,163	37,495	34,619
Total operating expenses	35,562	32,859	74,160	71,845
Income (loss) from operations	3,743	16,542	(10,358)	39,511
Other income (expense):
Interest income	1,570	1,680	3,222	2,775
Interest expense	(5,225)	(4,875)	(10,422)	(9,547)
Gain (loss) on foreign currency, net	503	(490)	411	(514)
Other income, net	142	366	371	567
Total other income (expense), net	(3,010)	(3,319)	(6,418)	(6,719)
Income (loss) before benefit from income taxes	733	13,223	(16,776)	32,792
Benefit from income taxes	(558)	(8,194)	(2,728)	(6,401)
Net income (loss)	1,291	21,417	(14,048)	39,193
Other comprehensive income—foreign currency translation adjustment	(646)	(1,665)	67	(503)
Comprehensive income (loss)	645	19,752	(13,981)	38,690
Net income (loss) attributable to common stockholders:
Basic and diluted	$ 1,291	$ 21,417	$ (14,048)	$ 39,193
Net income (loss) per share attributable to common stockholders:
Basic	$ 0.02	$ 0.26	$ (0.17)	$ 0.48
Diluted	$ 0.01	$ 0.23	$ (0.17)	$ 0.42
Weighted-average shares used to compute net income (loss) per share attributable to common stockholders:
Basic	83,884	83,257	83,605	82,447
Diluted	86,369	93,864	83,605	93,733
Product
Revenue:
Total revenue	$ 42,223	$ 58,537	$ 68,876	$ 138,727
Cost of revenue:
Total cost of revenue	10,976	18,560	20,405	44,340
Service
Revenue:
Total revenue	9,878	10,185	18,711	19,069
Cost of revenue:
Total cost of revenue	$ 1,820	$ 761	$ 3,380	$ 2,100