Commitments and Contingencies 2 (Details) - USD ($) $ in Millions				12 Months Ended
	Mar. 10, 2017	Oct. 24, 2016	May 29, 2014	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Rent expense, net				$ 138	$ 142	$ 144
Future purchase commitments				217
Future purchase commitments due within five years				198
Alleged damages suffered			excess of $100 million
Litigation settlement, Amount		$ (45)
Payment of litigation settlement	$ 45
Payment of attorneys' fees and litigation expenses	$ 4
Maximum
Loss Contingencies [Line Items]
Loss contingency, Estimate of possible loss				$ 20