SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Inventory (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Laboratory service revenue	$ 21,185	$ 8,119	$ 36,020	$ 12,385
Gross Profit	11,088	$ 3,025	16,864	$ 3,079
Inventory
Raw materials	2,149		2,149		$ 1,772
Semi-finished and finished goods	6,255		6,255		4,905
Total inventory	$ 8,404		$ 8,404		$ 6,677