Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Condensed Consolidated Statements of Operations
Laboratory service revenue	$ 118,291	$ 72,574	$ 311,481	$ 178,583
Cost of sales	30,020	20,729	79,822	55,701
Gross margin	88,271	51,845	231,659	122,882
Operating expenses:
Research and development	17,631	11,725	47,278	29,464
General and administrative	46,729	30,763	121,861	75,442
Sales and marketing	64,836	37,768	172,675	113,297
Total operating expenses	129,196	80,256	341,814	218,203
Loss from operations	(40,925)	(28,411)	(110,155)	(95,321)
Other income (expense)
Investment income	6,292	1,334	14,882	2,612
Interest expense	(10,704)	(51)	(25,817)	(155)
Total other income (expense)	(4,412)	1,283	(10,935)	2,457
Net loss before tax	(45,337)	(27,128)	(121,090)	(92,864)
Income tax benefit (expense)	(27)	231	(85)	231
Net loss	$ (45,364)	$ (26,897)	$ (121,175)	$ (92,633)
Net loss per share-basic and diluted (in dollars per share)	$ (0.37)	$ (0.23)	$ (0.99)	$ (0.81)
Weighted average common shares outstanding-basic and diluted (in shares)	122,671	119,215	121,946	114,246