Commitments And Contingencies (Narrative) (Details) $ in Millions	Sep. 30, 2016 USD ($)
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation	$ 2,535
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals	1
Amount of potential cash payments that could result from unrecognized tax benefits	86
Unrecorded Unconditional Purchase Obligation Payable in Common Stock Per Year | Maximum
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation	10
Unrecorded Unconditional Purchase Obligation Payable in Common Stock | Maximum
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation	$ 32