Pension Benefits (Schedule Of Sensitivity To Changes In Weighted-Average Discount Rate For Pension Plans) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
One percentage point increase on projected benefit obligation	$ (41)
One percentage point decrease on projected benefit obligation		48
One percentage point increase on net periodic pension cost	(3)
One percentage point decrease on net periodic pension cost		4
Foreign Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
One percentage point increase on projected benefit obligation	(149)
One percentage point decrease on projected benefit obligation		180
One percentage point increase on net periodic pension cost	(2)
One percentage point decrease on net periodic pension cost		$ 5