Pension Benefits (Schedule Of Net Periodic Expense For Pension Plans) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost-benefits earned during the year	$ 1	$ 4	$ 4
Interest cost on projected benefit obligation	19	19	21
Expected return on assets	(21)	(20)	(20)
Amortization of unrecognized actuarial loss, prior service costs and net transitional obligation	19	32	28
Curtailment gain	0	0	0
Net periodic expense (income)	18	35	33
Foreign Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost-benefits earned during the year	16	6	3
Interest cost on projected benefit obligation	34	11	7
Expected return on assets	(30)	(12)	(8)
Amortization of unrecognized actuarial loss, prior service costs and net transitional obligation	3	4	4
Curtailment gain	6	(1)	0
Net periodic expense (income)	$ 29	$ 8	$ 6