RESTRUCTURING CHARGES - Restructuring charges (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 4,209	$ 1,014
Workforce reduction
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	4,160	693
Other restructuring costs
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 49	$ 321