RESTRUCTURING CHARGES - Restructuring charges (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 4,895	$ 3,362	$ 9,104	$ 4,376
Workforce reduction
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	4,895	3,100	9,055	3,793
Other restructuring costs
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 0	$ 262	$ 49	$ 583