SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Property & Equipment and Patent Costs (Details) $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
	Apr. 25, 2017 USD ($)	Jun. 30, 2017 USD ($) item	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) item	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Property and equipment
Assets under construction		$ 9,095		$ 9,095		$ 6,711
Leasehold improvements		$ 13,682		13,682		13,549
Impairment of long-lived assets				$ 0		0
Software Capitalization Policy
Software development stages | item		3		3
Patent Costs and Intangible Assets
Accrued liabilities		$ 26,935		$ 26,935		28,106
Amortization of intangible assets				290	$ 100
Licensed Intellectual Property
Patent Costs and Intangible Assets
Intangible asset, net						1,600
Accrued liabilities						1,300
Amortization of intangible assets		200	$ 100	$ 300	$ 100
Amortization expense over remaining useful life
Total						$ 1,600
MDx | Licensed Intellectual Property
Patent Costs and Intangible Assets
Estimated useful life				10 years
Laboratory equipment | Minimum
Property and equipment
Estimated Useful Life				3 years
Laboratory equipment | Maximum
Property and equipment
Estimated Useful Life				5 years
Computer equipment and computer software
Property and equipment
Estimated Useful Life				3 years
Assets under construction		2,700		$ 2,700
Expected cost to complete construction of project		300		300
Leasehold improvements
Property and equipment
Assets under construction		1,200		1,200
Expected cost to complete construction of project		13,200		$ 13,200
Furniture and fixtures
Property and equipment
Estimated Useful Life				3 years
Buildings
Property and equipment
Estimated Useful Life				30 years
Machinery and equipment
Property and equipment
Assets under construction		5,200		$ 5,200
Expected cost to complete construction of project		10,600		$ 10,600
Royalty Buy-Out Agreement | Licensed Intellectual Property
Property and equipment
Estimated Useful Life				7 years
Patent Costs and Intangible Assets
Intangible asset, net		9,701		$ 9,701
Amortization expense over remaining useful life
2017		669		669
2018		1,338		1,338
2019		1,338		1,338
2020		1,338		1,338
2021		1,338		1,338
Thereafter		3,680		3,680
Total		$ 9,701		$ 9,701
Royalty Buy-Out Agreement | MDx
Patent Costs and Intangible Assets
One-time fee for a royalty-free, fully-paid, perpetual and assignable license to patents	$ 8,000
Payment for the assignment of certain other patent rights which were not covered by the original agreement	7,000
Total payment under second amendment to license agreement	15,000
Current liabilities related to the second amendment to the license agreement	$ 6,600
Royalty Buy-Out Agreement | MDx | Licensed Intellectual Property
Patent Costs and Intangible Assets
Estimated useful life	10 years