Pension Benefits (Schedule Of Changes In Benefit Obligations And Plan Assets) (Details) (Defined Pension Benefit Plans [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2012		Mar. 31, 2011		Mar. 31, 2010
Defined Pension Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of period	$ 625	[1]	$ 593
Service cost	7		6		4
Interest cost	31		31		35
Actuarial loss	42		21
Benefit payments	(34)		(32)
Foreign exchange impact and other	(1)		6
Benefit obligation at end of period	670	[1]	625	[1]	593
Fair value of plan assets at beginning of period	416		391
Actual return on plan assets	12		40
Employer and participant contributions	17		11
Benefits paid	(34)		(32)
Foreign exchange impact and other	(1)		6
Fair value of plan assets at end of period	410		416		391
Funded status at end of period	(260)		(209)
Long-term assets	0		4
Current liabilities	(13)		(4)
Long-term liabilities	(247)		(209)
Total	$ (260)		$ (209)

[1] The benefit obligation is the projected benefit obligation.