Goodwill, Capitalized Software and Other Intangible Assets 1 (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Mar. 31, 2013
Capitalized software and other intangible assets
Gross amortizable assets	$ 8,094	$ 7,941
Less: Fully amortized assets	5,934	5,825
Remaining amortizable assets	2,160	2,116
Accumulated amortization on remaining amortizable assets	946	885
Net assets	1,214	1,231
Purchased Software Products [Member]
Capitalized software and other intangible assets
Gross amortizable assets	5,703	5,597
Less: Fully amortized assets	4,779	4,735
Remaining amortizable assets	924	862
Accumulated amortization on remaining amortizable assets	323	309
Net assets	601	553
Internally Developed Software Products [Member]
Capitalized software and other intangible assets
Gross amortizable assets	1,559	1,528
Less: Fully amortized assets	675	661
Remaining amortizable assets	884	867
Accumulated amortization on remaining amortizable assets	396	327
Net assets	488	540
Other Intangible Assets [Member]
Capitalized software and other intangible assets
Gross amortizable assets	832	816
Less: Fully amortized assets	480	429
Remaining amortizable assets	352	387
Accumulated amortization on remaining amortizable assets	227	249
Net assets	$ 125	$ 138