Document and Entity Information - shares	3 Months Ended
	Jun. 30, 2018	Jul. 27, 2018
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, 2018
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Trading Symbol	NTCT
Amendment Flag	false
Entity Common Stock, Shares Outstanding		80,535,277