Long-Lived Assets 2 (Details) - USD ($) $ in Millions	Mar. 31, 2017	Mar. 31, 2016
Capitalized software and other intangible assets
Gross amortizable assets	$ 9,156	$ 8,384
Less: Fully amortized assets	6,755	6,602
Remaining amortizable assets	2,401	1,782
Accumulated amortization on remaining amortizable assets	1,094	987
Net assets	1,307	795
Purchased Software Products
Capitalized software and other intangible assets
Gross amortizable assets	6,496	5,990
Less: Fully amortized assets	4,914	4,865
Remaining amortizable assets	1,582	1,125
Accumulated amortization on remaining amortizable assets	667	552
Net assets	915	573
Internally Developed Software Products
Capitalized software and other intangible assets
Gross amortizable assets	1,467	1,467
Less: Fully amortized assets	1,029	1,009
Remaining amortizable assets	438	458
Accumulated amortization on remaining amortizable assets	391	333
Net assets	47	125
Other Intangible Assets
Capitalized software and other intangible assets
Gross amortizable assets	1,193	927
Less: Fully amortized assets	812	728
Remaining amortizable assets	381	199
Accumulated amortization on remaining amortizable assets	36	102
Net assets	$ 345	$ 97