Goodwill And Acquisition-Related Intangibles, Net (Schedule Of Amortization Of Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	$ 30	$ 43	$ 57
Cost Of Product [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	55	35	9
Cost Of Service And Other [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	38	17	3
Research and development [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	30	43	57
Total Amortization Included In Cost Of Revenue And Opertating Expense [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	$ 123	$ 95	$ 69