SEGMENT AND GEOGRAPHIC INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Total revenue	$ 235,002	$ 246,008	$ 223,797	$ 205,111	$ 235,224	$ 268,944	$ 256,863	$ 225,756	$ 909,918	$ 986,787	$ 1,162,112
United States
Segment Reporting Information [Line Items]
Total revenue									553,267	581,853	722,440
Europe
Segment Reporting Information [Line Items]
Total revenue									148,036	174,445	193,441
Asia
Segment Reporting Information [Line Items]
Total revenue									72,355	88,917	95,735
Rest of the world
Segment Reporting Information [Line Items]
Total revenue									$ 136,260	$ 141,572	$ 150,496