Goodwill, Capitalized Software and Other Intangible Assets 1 (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Mar. 31, 2013
Capitalized software and other intangible assets
Gross amortizable assets	$ 8,086	$ 7,941
Less: Fully amortized assets	5,820	5,825
Remaining amortizable assets	2,266	2,116
Accumulated amortization on remaining amortizable assets	973	885
Net assets	1,293	1,231
Purchased Software Products [Member]
Capitalized software and other intangible assets
Gross amortizable assets	5,707	5,597
Less: Fully amortized assets	4,735	4,735
Remaining amortizable assets	972	862
Accumulated amortization on remaining amortizable assets	337	309
Net assets	635	553
Internally Developed Software Products [Member]
Capitalized software and other intangible assets
Gross amortizable assets	1,552	1,528
Less: Fully amortized assets	656	661
Remaining amortizable assets	896	867
Accumulated amortization on remaining amortizable assets	373	327
Net assets	523	540
Other Intangible Assets [Member]
Capitalized software and other intangible assets
Gross amortizable assets	827	816
Less: Fully amortized assets	429	429
Remaining amortizable assets	398	387
Accumulated amortization on remaining amortizable assets	263	249
Net assets	$ 135	$ 138