Goodwill, Capitalized Software and Other Intangible Assets 1 (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Mar. 31, 2012
Capitalized software and other intangible assets
Gross Amortizable Assets	$ 7,887	$ 7,808
Less: Fully Amortized Assets	5,784	5,719
Remaining Amortizable Assets	2,103	2,089
Accumulated Amortization on Remaining Amortizable Assets	791	700
Net Assets	1,312	1,389
Purchased Software Products [Member]
Capitalized software and other intangible assets
Gross Amortizable Assets	5,631	5,628
Less: Fully Amortized Assets	4,740	4,733
Remaining Amortizable Assets	891	895
Accumulated Amortization on Remaining Amortizable Assets	275	228
Net Assets	616	667
Internally Developed Software Products [Member]
Capitalized software and other intangible assets
Gross Amortizable Assets	1,444	1,366
Less: Fully Amortized Assets	615	574
Remaining Amortizable Assets	829	792
Accumulated Amortization on Remaining Amortizable Assets	293	258
Net Assets	536	534
Other Intangible Assets [Member]
Capitalized software and other intangible assets
Gross Amortizable Assets	812	814
Less: Fully Amortized Assets	429	412
Remaining Amortizable Assets	383	402
Accumulated Amortization on Remaining Amortizable Assets	223	214
Net Assets	$ 160	$ 188