Consolidated Statements of Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue	$ 294,490	$ 348,201	$ 266,277
Cost of revenue	129,345	151,698	85,581
Gross profit	165,145	196,503	180,696
Operating expenses:
Research and development	167,924	200,539	108,013
Sales and marketing	43,080	42,381	26,534
General and administrative	28,302	23,782	21,201
Total operating expenses	239,306	266,702	155,748
Income (loss) from operations	(74,161)	(70,199)	24,948
Interest expense	(32,209)	(29,842)	(17,406)
Other income, net	2,408	3,961	3,914
Income (loss) before income taxes from continuing operations	(103,962)	(96,080)	11,456
Benefit for income taxes	(8,211)	(21,176)	(15,057)
Net income (loss) from continuing operations	(95,751)	(74,904)	26,513
Discontinued operations:
Gain from sale			78,544
Loss from discontinued operations			(3,802)
Provision for income taxes			(1,799)
Net income from discontinued operations			72,943
Net income (loss)	$ (95,751)	$ (74,904)	$ 99,456
Basic
Net income (loss) from continuing operations (in dollars per share)	$ (2.19)	$ (1.78)	$ 0.65
Net income from discontinued operations (in dollars per share)			1.80
Basic earnings per share (in dollars per share)	(2.19)	(1.78)	2.45
Diluted
Net income (loss) from continuing operations (in dollars per share)	(2.19)	(1.78)	0.60
Net income from discontinued operations (in dollars per share)			1.65
Diluted earnings per share (in dollars per share)	$ (2.19)	$ (1.78)	$ 2.25
Weighted-average shares used in computing earnings per share:
Basic (in shares)	43,690,581	42,165,213	40,565,433
Diluted (in shares)	43,690,581	42,165,213	44,124,881