ACQUISITIONS - Schedule of Pro Forma Results of Consolidated Statement of Operations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Business Acquisition, Pro Forma Information [Abstract]
Pro forma revenue	$ 1,131,626	$ 1,177,938
Pro forma net income (loss)	$ (58,806)	$ (2,323)
Pro forma income (loss) per share:
Basic (in dollars per share)	$ (0.59)	$ (0.02)
Diluted (in dollars per share)	$ (0.59)	$ (0.02)
Pro forma shares outstanding
Basic (in shares)	99,687	103,573
Diluted (in shares)	99,687	103,573

Business Acquisition, Pro Forma Earnings Per Share, Basic and Diluted [Abstract]

No definition available.

Name:	ntct_BusinessAcquisitionProFormaEarningsPerShareBasicandDilutedAbstract
Namespace Prefix:	ntct_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Pro Forma Weighted Average Shares Outstanding, Basic and Diluted [Abstract]

+ References

No definition available.

+ Details

Name:	ntct_ProFormaWeightedAverageSharesOutstandingBasicandDilutedAbstract
Namespace Prefix:	ntct_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1392-128463

+ Details

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

- Definition

The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

+ Details

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

- References

No definition available.

+ Details

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

- Definition

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

+ Details

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

- Definition

The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

+ References

+ Details

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

- Definition

The weighted average number of shares or units and dilutive common stock or unit equivalents outstanding in the calculation of proforma diluted earnings per share (earnings per unit), which is commonly presented in initial public offerings based on the terms of the offering.

+ References

No definition available.

+ Details

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

- Definition

The weighted average number of shares (units) outstanding in the calculation of pro forma basic earnings per share (earnings per unit), which is commonly presented in initial public offerings based on the terms of the offering.

+ References

No definition available.

+ Details

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