Consolidated Statements of Operations - USD ($) shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue Recognition
Product revenues	$ 92,625,000	$ 83,979,000
Operating expenses:
Cost of product revenues	18,733,000	13,672,000
Research and development	16,807,000	14,874,000
Selling and marketing	41,755,000	41,507,000
General and administrative	19,718,000	16,751,000
Total operating expenses	97,013,000	86,804,000
Loss from operations	(4,388,000)	(2,825,000)
Interest income	417,000	158,000
Gain on sale of equity securities		2,807,000
Unrealized gain on equity securities	127,000
Other income, net	309,000	95,000
Income (loss) before income taxes	(3,535,000)	235,000
Income tax expense	240,000	1,041,000
Net loss	$ (3,775,000)	$ (806,000)
Basic and diluted net loss per share (in dollars per share)	$ (0.11)	$ (0.02)
Shares used in computing basic and diluted net loss per share (in shares)	35,198	34,009