Condensed Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Statements of Comprehensive Income [Abstract]
Net Income	$ 401	$ 296	$ 781	$ 582
Other Comprehensive Income (Loss), net of tax
Foreign Currency Translation Adjustments, Net of Income Tax Expense (Benefit) of ($2), $1, $2 and $8	71	(128)	30	(117)
Other, Net of Income Tax Expense of $2, $1, $5 and $4	5	4	11	9
Total Other Comprehensive Income (Loss)	76	(124)	41	(108)
Comprehensive Income	$ 477	$ 172	$ 822	$ 474