Condensed Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Statement of Comprehensive Income [Abstract]
Foreign currency translation adjustments, income tax expense of $2 and $4	$ 2	$ 4
Unrealized gains on cash flow hedges, income tax expense of nil and nil	0	0
Retirement related benefit plans, income tax expense of $4 and $3	$ 4	$ 3