Pension Benefits (Schedule Of Other Changes In Accumulated Other Comprehensive Income) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ (31)
Prior service (cost) credit	7
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	58	(31)	59
Prior service credit	0	(8)	0
Net actuarial loss	(27)	(32)	(27)
Prior service (cost) credit	8	0	(1)
Foreign exchange impact and other	0	(1)	0
Total recognized in net periodic benefit cost and other comprehensive loss (income)	39	(72)	31
Foreign Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	117	12	11
Prior service credit	(8)	0	0
Net actuarial loss	(5)	(4)	(4)
Prior service (cost) credit	2	2	0
Foreign exchange impact and other	(8)	4	(4)
Total recognized in net periodic benefit cost and other comprehensive loss (income)	$ 98	$ 14	$ 3