FAIR VALUE MEASUREMENT OF ASSETS AND LIABILITIES - Assets and Liabilities Measured at Fair Value (Details) - Recurring basis - USD ($) $ in Thousands	Dec. 31, 2019	Mar. 31, 2019
Money market funds and time deposits
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total assets	$ 373,644	$ 473,888
Foreign currency contracts
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total assets	46,042	27,277
Total liabilities	(31,631)	(27,426)
Mutual funds, money market accounts and equity securities
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total assets	58,204	79,697
Level 1 | Money market funds and time deposits
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total assets	0	0
Level 1 | Foreign currency contracts
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total assets	0	0
Total liabilities	0	0
Level 1 | Mutual funds, money market accounts and equity securities
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total assets	0	2,845
Level 2 | Money market funds and time deposits
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total assets	373,644	473,888
Level 2 | Foreign currency contracts
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total assets	46,042	27,277
Total liabilities	(31,631)	(27,426)
Level 2 | Mutual funds, money market accounts and equity securities
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total assets	58,204	76,852
Level 3 | Money market funds and time deposits
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total assets	0	0
Level 3 | Foreign currency contracts
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total assets	0	0
Total liabilities	0	0
Level 3 | Mutual funds, money market accounts and equity securities
Financial Instruments Measured at Fair Value on a Recurring Basis and Nonrecurring Basis
Total assets	$ 0	$ 0