FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents	$ 109,288	$ 112,531	$ 116,690
Accumulated gross unrealized gain, before tax	32	60
Accumulated gross unrealized loss, before tax	(5)	0
Cash, cash equivalents and debt securities available-for-sale, amortized cost	161,845	161,449
Cash, cash equivalents and debt securities available-for-sale	161,872	161,509
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accumulated gross unrealized gain, before tax	0	17
Accumulated gross unrealized loss, before tax	0	0
Cash, cash equivalents and debt securities available-for-sale, amortized cost	106,588	112,959
Cash, cash equivalents and debt securities available-for-sale	106,588	112,976
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized cost	55,257	48,490
Accumulated gross unrealized gain, before tax	32	43
Accumulated gross unrealized loss, before tax	(5)	0
Debt securities, available-for-sale	55,284	48,533
Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents	39,480	39,070
Cash and cash equivalents, fair value	39,480	39,070
Money market funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents	67,108	67,712
Cash and cash equivalents, fair value	67,108	67,712
Treasury securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized cost		6,177
Accumulated gross unrealized gain, before tax		17
Accumulated gross unrealized loss, before tax		0
Debt securities, available-for-sale		6,194
Certificate of deposit | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents	8,641	8,641
Cash and cash equivalents, fair value	8,641	8,641
Municipal bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents	700
Cash and cash equivalents, fair value	700
Commercial paper | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized cost	15,120	17,656
Accumulated gross unrealized gain, before tax	2	42
Accumulated gross unrealized loss, before tax	0	0
Debt securities, available-for-sale	15,122	17,698
Corporate debt | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized cost	30,796	22,193
Accumulated gross unrealized gain, before tax	30	1
Accumulated gross unrealized loss, before tax	(5)	0
Debt securities, available-for-sale	30,821	22,194
Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash, cash equivalents and debt securities available-for-sale	109,288	112,531
Cash and Cash Equivalents | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash, cash equivalents and debt securities available-for-sale	106,588	106,782
Cash and Cash Equivalents | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	2,700	5,749
Cash and Cash Equivalents | Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents	39,480	39,070
Cash and Cash Equivalents | Money market funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents	67,108	67,712
Cash and Cash Equivalents | Municipal bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents	700
Cash and Cash Equivalents | Commercial paper | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	2,000	700
Cash and Cash Equivalents | Corporate debt | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	0	5,049
Restricted Cash (Current & Non-Current)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash, cash equivalents and debt securities available-for-sale	8,641	8,641
Restricted Cash (Current & Non-Current) | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash, cash equivalents and debt securities available-for-sale	0	0
Restricted Cash (Current & Non-Current) | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	8,641	8,641
Restricted Cash (Current & Non-Current) | Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents	0	0
Restricted Cash (Current & Non-Current) | Certificate of deposit | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents	8,641	8,641
Short-Term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash, cash equivalents and debt securities available-for-sale	31,231	40,337
Short-Term Investments | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	0	6,194
Short-Term Investments | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	31,231	34,143
Short-Term Investments | Treasury securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale		6,194
Short-Term Investments | Commercial paper | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	13,122	16,998
Short-Term Investments | Corporate debt | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	18,109	17,145
Long-Term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash, cash equivalents and debt securities available-for-sale	12,712	0
Long-Term Investments | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	0	0
Long-Term Investments | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	12,712	0
Long-Term Investments | Treasury securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale		0
Long-Term Investments | Certificate of deposit | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	0
Long-Term Investments | Corporate debt | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	$ 12,712	$ 0