Stock-Based Compensation (Schedule Of Stock-Based Compensation Expense Recognized In Our Condensed Consolidated Statements Of Income) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 28, 2012	Sep. 30, 2011	Sep. 28, 2012	Sep. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 45	$ 38	$ 83	$ 77
Tax benefit associated with stock-based compensation expense	(14)	(11)	(24)	(22)
Net stock-based compensation expense	31	27	59	55
Net stock-based compensation expense per share attributable to Symantec Corporation stockholders- basic	$ 0.04	$ 0.04	$ 0.08	$ 0.07
Net stock-based compensation expense per share attributable to Symantec Corporation stockholders- diluted	$ 0.04	$ 0.04	$ 0.08	$ 0.07
Cost of Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	4	3	8	8
Sales And Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	17	17	33	32
Research And Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	13	12	24	23
General And Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 11	$ 6	$ 18	$ 14