Condensed Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Statements of Comprehensive Income [Abstract]
Net Income	$ 298	$ 300	$ 1,079	$ 882
Other Comprehensive Income (Loss), net of tax
Foreign Currency Translation Adjustments, Net of Income Tax Expense (Benefit) of ($4), ($6), ($2) and $2	(16)	20	14	(97)
Other, Net of Income Tax Expense of $3, $3, $8 and $7	5	3	16	12
Total Other Comprehensive Income (Loss)	(11)	23	30	(85)
Comprehensive Income	$ 287	$ 323	$ 1,109	$ 797