Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Other Comprehensive Income (Loss), Tax, Parenthetical Disclosures [Abstract]
Foreign currency translation adjustments arising during period, tax expense (benefit) of $24, ($2) and $2	$ 24	$ (2)	$ 2
Unrealized losses on cash flow hedges arising during period, tax benefit of nil, nil and nil	0	0	0
Retirement related benefits plans, net of income tax expense (benefit) of $29, ($10) and ($9)	$ 29	$ (10)	$ (9)