Document and Entity Information	6 Months Ended
	Sep. 30, 2012	Oct. 26, 2012
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2012
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q2
Trading Symbol	NTCT
Entity Registrant Name	NETSCOUT SYSTEMS INC
Entity Central Index Key	0001078075
Current Fiscal Year End Date	--03-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		41,801,152