COMMITMENTS AND CONTINGENCIES - LEASES (Details) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Apr. 30, 2012 ft² item	Jun. 30, 2014	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Future minimum payments under operating leases for facilities
2016			$ 4,442
2017			3,309
2018			2,416
2019			1,578
2020			1,621
Thereafter			3,245
Total future minimum lease payments			16,611
Enterprise FM Trust
Future minimum payments under operating leases for facilities
Total future minimum lease payments			5,700
Enterprise FM Trust | Minimum
Future minimum payments under operating leases for facilities
Lessee Leasing Arrangements, Operating Leases, Term of Contract		18 months
Enterprise FM Trust | Maximum
Future minimum payments under operating leases for facilities
Lessee Leasing Arrangements, Operating Leases, Term of Contract		36 months
Lease of cars
Future minimum payments under operating leases for facilities
Rent expense			2,200	$ 1,100
Office and laboratory
Future minimum payments under operating leases for facilities
Rent expense			600	700
New lease Newark
Future minimum payments under operating leases for facilities
Total future minimum lease payments			10,900
Square feet agreed to lease | ft²	52,500
Additional square feet obligated lease | ft²	8,000
Number of lease renewal terms | item	1
Lease renewal option period	5 years
Lease renewal, minimum notice period prior to lease expiration	12 months
Lease termination penalty interest (as a percent)	8.00%
Deferred rent			$ 1,700	$ 1,700