FAIR VALUE MEASUREMENTS - Schedule of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020
ASSETS:
Cash and cash equivalents	$ 403,306	$ 338,489
Available-for-sale securities	23,202	50,582
Derivative financial instruments	21
Total assets	426,529	389,071
LIABILITIES:
Contingent purchase consideration	(748)	(1,748)
Derivative financial instruments	(20)	(49)
Total liabilities	(768)	(1,797)
U.S. government and municipal obligations
ASSETS:
Available-for-sale securities	10,640	31,341
Commercial paper
ASSETS:
Available-for-sale securities	10,626	14,644
Corporate bonds
ASSETS:
Available-for-sale securities	1,936	4,597
Level 1
ASSETS:
Cash and cash equivalents	403,306	338,489
Derivative financial instruments	0
Total assets	415,882	374,427
LIABILITIES:
Contingent purchase consideration	0	0
Derivative financial instruments	0	0
Total liabilities	0	0
Level 1 \| U.S. government and municipal obligations
ASSETS:
Available-for-sale securities	10,640	31,341
Level 1 \| Commercial paper
ASSETS:
Available-for-sale securities	0	0
Level 1 \| Corporate bonds
ASSETS:
Available-for-sale securities	1,936	4,597
Level 2
ASSETS:
Cash and cash equivalents	0	0
Derivative financial instruments	21
Total assets	10,647	14,644
LIABILITIES:
Contingent purchase consideration	0	0
Derivative financial instruments	(20)	(49)
Total liabilities	(20)	(49)
Level 2 \| U.S. government and municipal obligations
ASSETS:
Available-for-sale securities	0	0
Level 2 \| Commercial paper
ASSETS:
Available-for-sale securities	10,626	14,644
Level 2 \| Corporate bonds
ASSETS:
Available-for-sale securities	0	0
Level 3
ASSETS:
Cash and cash equivalents	0	0
Derivative financial instruments	0
Total assets	0	0
LIABILITIES:
Contingent purchase consideration	(748)	(1,748)
Derivative financial instruments	0	0
Total liabilities	(748)	(1,748)
Level 3 \| U.S. government and municipal obligations
ASSETS:
Available-for-sale securities	0	0
Level 3 \| Commercial paper
ASSETS:
Available-for-sale securities	0	0
Level 3 \| Corporate bonds
ASSETS:
Available-for-sale securities	$ 0	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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