Collaboration and Commercial Technology Licensing Agreements (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2013
Specimen transfer agreements
Collaboration payments and costs
Collaboration expense	$ 938,000	$ 7,100,000
Technology license agreements
Collaboration payments and costs
Costs recorded under collaborative arrangements	2,500,000	2,200,000
Exclusive license agreement
Collaboration payments and costs
Collaboration expense		5,500,000
Estimated total remaining obligation, including milestone payments	$ 0
Exclusive license agreement | Research and development expense.
Collaboration payments and costs
Up-front payment			$ 9,000,000
Milestone payment		$ 5,500,000
Oncotype DX DCIS score agreement
Collaboration payments and costs
Period from achieving key milestone entity required to make fixed annual payments	1 year
Fixed annual payments
2016	$ 604,000
2017	$ 504,000