DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Mar. 31, 2018
Derivative [Line Items]
Forward contracts to sell foreign currencies	$ 345,710		$ 345,710		$ 67,580
Forward contracts to purchase foreign currencies	10,329		10,329		$ 4,359
Derivative instrument not designated as hedging instruments, gain (loss), net	(247)	$ (6,102)	2,157	$ (14,705)
Cash Flow Hedging | Foreign currency forward contracts
Derivative [Line Items]
Derivative, notional amount	$ 129,000		$ 129,000