Stock Repurchase Program, Number Of Dealers

No definition available.

Name:	ntct_StockRepurchaseProgramNumberOfDealers
Namespace Prefix:	ntct_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Stock Repurchase Program, Percentage Of Total Number Of Shares Expected To be Repurchased

+ References

No definition available.

+ Details

Name:	ntct_StockRepurchaseProgramPercentageOfTotalNumberOfSharesExpectedTobeRepurchased
Namespace Prefix:	ntct_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Treasury Stock, Shares, Acquired From Each Of Dealers

+ References

No definition available.

+ Details

Name:	ntct_TreasuryStockSharesAcquiredFromEachOfDealers
Namespace Prefix:	ntct_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

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

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

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

- Definition

The cash outflow to reacquire common stock during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585

+ Details

Name:	us-gaap_PaymentsForRepurchaseOfCommonStock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The remaining number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655

+ Details

Name:	us-gaap_TreasuryStockAcquiredAverageCostPerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares that have been repurchased during the period and are being held in treasury.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_TreasuryStockSharesAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=ntct_DealerOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=ntct_DealerTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareRepurchaseProgramAxis=ntct_ShareRepurchaseProgramMay2015Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareRepurchaseProgramAxis=ntct_ASRAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareRepurchaseProgramAxis=ntct_ShareRepurchaseProgramOctober2017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

TREASURY STOCK (Details) $ / shares in Units, $ in Thousands			7 Months Ended	12 Months Ended
	Feb. 02, 2018 USD ($) shares	Feb. 01, 2018 USD ($) dealer shares	Aug. 31, 2018 $ / shares shares	Mar. 31, 2019 USD ($) shares	Mar. 31, 2018 USD ($) shares	Mar. 31, 2017 USD ($) shares	Jan. 16, 2018 shares	Oct. 24, 2017 shares	May 19, 2015 shares
Equity, Class of Treasury Stock [Line Items]
Stock authorized to repurchase under stock repurchase program (in shares)							25,000,000
Shares repurchased during the period, value \| $				$ 14,468	$ 501,324	$ 79,996
Restricted stock units
Equity, Class of Treasury Stock [Line Items]
Shares repurchased during the period (in shares)				451,683	408,097	320,572
Shares repurchased during the period, value \| $				$ 11,900	$ 13,600	$ 9,600
Dealer one
Equity, Class of Treasury Stock [Line Items]
Shares repurchased during the period, value \| $	$ 150,000
Dealer two
Equity, Class of Treasury Stock [Line Items]
Shares repurchased during the period, value \| $	$ 150,000
Line of credit \| Senior secured revolving credit facility
Equity, Class of Treasury Stock [Line Items]
Amount outstanding under credit facility \| $		$ 300,000		$ 550,000
Share repurchase program, May 2015
Equity, Class of Treasury Stock [Line Items]
Stock authorized to repurchase under stock repurchase program (in shares)									20,000,000
Shares repurchased during the period (in shares)		970,650			6,773,438	3,148,426
Shares repurchased during the period, value \| $		$ 27,600			$ 227,600	$ 80,000
Common stock available to be purchased (in shares)					0
ASR Agreements
Equity, Class of Treasury Stock [Line Items]
Shares repurchased during the period (in shares)			11,067,809	3,679,947	7,387,862
Shares repurchased during the period, value \| $		$ 300,000		$ 96,800
Number of third-party financial institutions (the Dealers) \| dealer		2
Shares repurchased during the period from each of the dealers (in shares)	3,693,931
Shares repurchased as percentage of total expected to be repurchased	70.00%
Average cost per share (in dollars per share) \| $ / shares			$ 27.11
Share repurchase program, October 2017
Equity, Class of Treasury Stock [Line Items]
Stock authorized to repurchase under stock repurchase program (in shares)								25,000,000
Shares repurchased during the period (in shares)		6,417,212		543,251
Shares repurchased during the period, value \| $		$ 182,400		$ 14,500
Common stock available to be purchased (in shares)				14,359,590