Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue:
Product revenue	$ 89,003	$ 102,140	$ 107,071
Service revenue	15,205	12,315	8,844
License revenue	238	257	323
Grant revenue	0	0	218
Total revenue	104,446	114,712	116,456
Costs and expenses:
Cost of product revenue	41,110	43,001	39,511
Cost of service revenue	4,899	3,629	3,338
Research and development	38,415	39,264	43,423
Selling, general and administrative	93,212	82,959	71,324
Acquisition-related expenses	0	0	10,696
Gain on escrow settlement	0	(3,986)	0
Total costs and expenses	177,636	164,867	168,292
Loss from operations	(73,190)	(50,155)	(51,836)
Interest expense	(5,820)	(5,808)	(5,344)
Gain from sale of investment in Verinata	0	2,330	332
Other expense, net	(1,167)	(1,157)	(857)
Loss before income taxes	(80,177)	(54,790)	(57,705)
Benefit from income taxes	4,192	1,475	4,875
Net loss	$ (75,985)	$ (53,315)	$ (52,830)
Net loss per share, basic and diluted (usd per share)	$ (2.62)	$ (1.86)	$ (1.90)
Shares used in computing net loss per share, basic and diluted (shares)	29,008	28,711	27,768