Document and Entity Information - USD ($)	12 Months Ended
	Mar. 31, 2016	May. 16, 2016	Sep. 30, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	NETSCOUT SYSTEMS INC
Trading Symbol	NTCT
Entity Central Index Key	0001078075
Current Fiscal Year End Date	--03-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		93,757,507
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 3,413,523,295