Long-Lived Assets 1 (Details) - USD ($) $ in Millions	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Property and equipment
Total property and equipment	$ 1,078	$ 1,074
Accumulated depreciation and amortization	(841)	(832)
Property and equipment, net	237	242	$ 252
Land and Buildings
Property and equipment
Total property and equipment	172	188
Equipment, Software Developed For Internal Use, Furniture and Leasehold Improvements
Property and equipment
Total property and equipment	$ 906	$ 886