NET LOSS PER SHARE - Antidilutive Securities (Details) - shares shares in Thousands	3 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential anti-dilutive shares (in shares)	14,340	12,284
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential anti-dilutive shares (in shares)	1,413	2,259
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential anti-dilutive shares (in shares)	12,483	9,443
Potential shares attributable to the ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential anti-dilutive shares (in shares)	444	582