DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Narrative (Details)	12 Months Ended
Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Managing period of hedging forecasted cash flows for operating expenses denominated in foreign currencies	12 months
Contract maturity period	12 months

Hedging Forecasted Cash Flows For Operating Expenses Denominated In Foreign Currencies Managed In Months

No definition available.

Name:	ntct_HedgingForecastedCashFlowsForOperatingExpensesDenominatedInForeignCurrenciesManagedInMonths
Namespace Prefix:	ntct_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration