ACCUMULATED OTHER COMPREHENSIVE LOSS (Details) - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Changes in accumulated other comprehensive loss
Balance	$ (15,732)	$ (47,142)
Other comprehensive (loss) income before reclassifications	(14,391)	18,106
Amounts reclassified from accumulated other comprehensive loss	(7,076)	564
Balance	(37,199)	(28,472)
Foreign currency translation adjustments
Changes in accumulated other comprehensive loss
Balance	(4,287)	(47,666)
Other comprehensive (loss) income before reclassifications	(24,335)	23,776
Amounts reclassified from accumulated other comprehensive loss	0	0
Balance	(28,622)	(23,890)
Unrealized gain (loss) on forward contracts
Changes in accumulated other comprehensive loss
Balance	600	600
Other comprehensive (loss) income before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive loss	0	0
Balance	600	600
Unrealized gain (loss) on cross-currency swap
Changes in accumulated other comprehensive loss
Balance	(10,191)	0
Other comprehensive (loss) income before reclassifications	9,054	(5,781)
Amounts reclassified from accumulated other comprehensive loss	(7,076)	564
Balance	(8,213)	(5,217)
Unrealized gain (loss) on available-for- sales securities
Changes in accumulated other comprehensive loss
Balance	(1,854)	(76)
Other comprehensive (loss) income before reclassifications	890	111
Amounts reclassified from accumulated other comprehensive loss	0	0
Balance	$ (964)	$ 35