Commitments And Contingencies (Narrative) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Mar. 31, 2013
Loss Contingencies [Line Items]
Amount of potential cash payments that could result from unrecognized tax benefits	$ 256
Maximum additional consideration payable for business acquisition	560	566
Accrued contingent consideration	47
Estimated litigation liability	27
Compensatory Damages [Member]
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss	4
Prejudgment Interest [Member]
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss	$ 8