Document And Entity Information - USD ($)	12 Months Ended
	Mar. 31, 2017	Apr. 28, 2017	Sep. 30, 2016
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY
Entity Registrant Name	SYMANTEC CORP
Entity Central Index Key	0000849399
Current Fiscal Year End Date	--03-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		608,240,301
Entity Public Float			$ 15,559,432,822
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No