Divestitures 1 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Income (loss) from the discontinued components
Income from discontinued operations, net of taxes	$ 0	$ 0	$ 0	$ 13
Internet Security Business [Member]
Income (loss) from the discontinued components
Subscription and maintenance revenue				15
Total revenue				15
Loss from operations of discontinued components, net of tax benefit of $6 million				(10)
Gain on disposal of discontinued components, net of taxes				23
Income from discontinued operations, net of taxes				$ 13