MYOSCIENCE ACQUISITION (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Apr. 09, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Business Acquisition [Line Items]
Income (loss) before income taxes		$ 1,127	$ 2,599	$ (1,390)	$ (8,046)
Valuation allowance on deferred tax assets		1,800		1,800
Myoscience Acquisition
Business Acquisition [Line Items]
Initial cash payment		120,000
Fair value of contingent consideration	$ 28,470
Contingent consideration		100,000
Contingent consideration maximum amount payable in shares	$ 25,000
Payment term	60 days
Total consideration transferred		148,499
Net income (loss)		$ 4,234	$ (3,519)	$ (4,742)	$ (20,496)