Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue
Laboratory service revenue	$ 28,115	$ 12,632	$ 64,135	$ 25,017
Cost of sales	12,174	7,528	31,330	16,834
Gross margin	15,941	5,104	32,805	8,183
Operating expenses:
Research and development	7,625	9,863	26,391	24,549
General and administrative	20,292	15,432	55,400	42,086
Sales and marketing	26,308	23,079	82,320	60,196
Total operating expenses	54,225	48,374	164,111	126,831
Loss from operations	(38,284)	(43,270)	(131,306)	(118,648)
Other income (expense)
Investment income	535	365	1,426	780
Interest income (expense)	(54)	(40)	(161)	56
Total other income	481	325	1,265	836
Net loss	$ (37,803)	$ (42,945)	$ (130,041)	$ (117,812)
Net loss per share-basic and diluted (in dollars per share)	$ (0.36)	$ (0.45)	$ (1.30)	$ (1.30)
Weighted average common shares outstanding-basic and diluted (in shares)	104,807	94,444	100,006	90,696