Cover Page - USD ($)	12 Months Ended
	Mar. 31, 2020	May 11, 2020	Sep. 30, 2019
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	000-26251
Entity Registrant Name	NETSCOUT SYSTEMS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-2837575
Entity Address, Address Line One	310 Littleton Road
Entity Address, City or Town	Westford
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01886
City Area Code	978
Local Phone Number	614-4000
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	NTCT
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		72,220,906
Entity Public Float			$ 1,654,986,360
Documents Incorporated by Reference	Portions of the Registrant’s Proxy Statement for the fiscal year 2020 Annual Meeting of Stockholders, which will be made available on the Company's website at ir.netscout.com and at the SEC's website at www.sec.gov, are incorporated by reference into Part III of this Annual Report on Form 10-K. Except as expressly incorporated by reference, the proxy statement is not deemed to be part of this report.
Entity Central Index Key	0001078075
Current Fiscal Year End Date	--03-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false