Lease Obligations (Schedule Of Future Minimum Rental Payments For Operating Leases) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012
Lease Obligations [Abstract]
2013	$ 188
2014	157
2015	123
2016	92
2017	75
Thereafter	233
Total minimum lease payments	868	[1]
Minimum sublease rentals, due under future noncancelable subleases	$ 74

[1] Minimum lease payments have not been reduced by minimum sublease rentals of $74 million due under future noncancelable subleases.