CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Mar. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 64,183	$ 67,071
Unrealized Losses	(15)	(34)
Fair Value	64,168	67,037
Short-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	57,264	67,071
Unrealized Losses	(2)	(34)
Fair Value	57,262	67,037
Long-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	6,919	0
Unrealized Losses	(13)	0
Fair Value	6,906	0
U.S. government and municipal obligations
Debt Securities, Available-for-sale [Line Items]
Fair Value	26,116	40,863
U.S. government and municipal obligations \| Short-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	19,211	40,895
Unrealized Losses	(1)	(32)
Fair Value	19,210	40,863
U.S. government and municipal obligations \| Long-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	6,919
Unrealized Losses	(13)
Fair Value	6,906
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Fair Value	33,487	23,353
Commercial paper \| Short-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	33,487	23,353
Unrealized Losses	0	0
Fair Value	33,487	23,353
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value	1,129	821
Corporate bonds \| Short-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,130	823
Unrealized Losses	(1)	(2)
Fair Value	1,129	821
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Fair Value	3,436	2,000
Certificates of deposit \| Short-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	3,436	2,000
Unrealized Losses	0	0
Fair Value	$ 3,436	$ 2,000

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27161-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

+ Details

Name:	us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124260329&loc=d3e26610-111562

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, before tax, of unrealized gain (loss) in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

No definition available.

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainLossBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_BalanceSheetLocationAxis=ntct_ShortTermMarketableSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=ntct_LongTermMarketableSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CertificatesOfDepositMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: