Goodwill, Capitalized Software and Other Intangible Assets 1 (Details) - USD ($) $ in Millions	Dec. 31, 2016	Mar. 31, 2016
Capitalized software and other intangible assets
Gross amortizable assets	$ 8,408	$ 8,384
Less: Fully amortized assets	6,749	6,602
Remaining amortizable assets	1,659	1,782
Accumulated amortization on remaining amortizable assets	1,032	987
Net assets	627	795
Purchased Software Products
Capitalized software and other intangible assets
Gross amortizable assets	6,014	5,990
Less: Fully amortized assets	4,914	4,865
Remaining amortizable assets	1,100	1,125
Accumulated amortization on remaining amortizable assets	622	552
Net assets	478	573
Internally Developed Software Products
Capitalized software and other intangible assets
Gross amortizable assets	1,467	1,467
Less: Fully amortized assets	1,030	1,009
Remaining amortizable assets	437	458
Accumulated amortization on remaining amortizable assets	374	333
Net assets	63	125
Other Intangible Assets
Capitalized software and other intangible assets
Gross amortizable assets	927	927
Less: Fully amortized assets	805	728
Remaining amortizable assets	122	199
Accumulated amortization on remaining amortizable assets	36	102
Net assets	$ 86	$ 97