RESTRUCTURING CHARGES - Schedule of Accrued Restructuring and Severance Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019
Accrued restructuring and severance costs rollforward
Balance at beginning of period			$ 1,578
Balance at end of period	$ 435
Employee compensation costs
Accrued restructuring and severance costs rollforward
Balance at beginning of period	478	$ 820	1,578
Cash paid	(43)	(342)	(758)
Balance at end of period	$ 435	$ 478	$ 820