Document and Entity Information	3 Months Ended
	Jun. 30, 2014	Jul. 24, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	NETSCOUT SYSTEMS INC
Entity Central Index Key	0001078075
Current Fiscal Year End Date	--03-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2014
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	NTCT
Amendment Flag	false
Entity Common Stock, Shares Outstanding		41,052,266