Long-Lived Assets 3 (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Depreciation and amortization expense
Depreciation	$ 58	$ 62	$ 71
Total depreciation and amortization expense	320	362	402
Purchased Software Products
Depreciation and amortization expense
Amortization of intangible assets	164	146	124
Internally Developed Software Products
Depreciation and amortization expense
Amortization of intangible assets	79	110	149
Other Intangible Assets
Depreciation and amortization expense
Amortization of intangible assets	$ 19	$ 44	$ 58