Liabilities, Commitments And Contingencies (Schedule Of Estimated Potential Funding Dates For Financing Commitments) (Details) (Financing Commitment [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Financing Commitment [Member]
Other Commitments, Fiscal Year Maturity [Line Items]
2013	$ 1,341
2014	2,591
2015	3,997
2016	3,457
2017	2,796
Thereafter	3,901
Total	$ 18,083	$ 15,866