INTANGIBLE ASSETS - Amounts Allocated to Intangible Assets from Acquisitions (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Mar. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 122,404	$ 122,479
Accumulated amortization	(117,043)	(112,611)
Total finite-lived intangible assets, net	5,361	9,868
Developed technology, gross
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	72,028	72,095
Accumulated amortization	(66,698)	(63,658)
Total finite-lived intangible assets, net	5,330	8,437
Customer relationship/trade name, gross
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	34,376	34,384
Accumulated amortization	(34,345)	(33,953)
Total finite-lived intangible assets, net	31	431
Publisher/data supply relationships, gross
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	16,000	16,000
Accumulated amortization	(16,000)	(15,000)
Total finite-lived intangible assets, net	$ 0	$ 1,000