Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenue
Laboratory service revenue	$ 72,574	$ 28,115	$ 178,583	$ 64,135
Cost of sales	20,729	12,174	55,701	31,330
Gross margin	51,845	15,941	122,882	32,805
Operating expenses:
Research and development	11,725	7,625	29,464	26,391
General and administrative	30,763	20,292	75,442	55,400
Sales and marketing	37,768	26,308	113,297	82,320
Total operating expenses	80,256	54,225	218,203	164,111
Loss from operations	(28,411)	(38,284)	(95,321)	(131,306)
Other income (expense)
Investment income	1,334	535	2,612	1,426
Interest expense	(51)	(54)	(155)	(161)
Total other income	1,283	481	2,457	1,265
Net loss before tax	(27,128)	(37,803)	(92,864)	(130,041)
Income tax benefit	231		231
Net loss	$ (26,897)	$ (37,803)	$ (92,633)	$ (130,041)
Net loss per share-basic and diluted (in dollars per share)	$ (0.23)	$ (0.36)	$ (0.81)	$ (1.30)
Weighted average common shares outstanding-basic and diluted (in shares)	119,215	104,807	114,246	100,006