Income Taxes (Schedule Of Reconciliation Of U.S. Federal Statutory Tax Rate To Our Effective Income Tax Rate) (Details) - USD ($) $ in Millions		3 Months Ended			12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Examination [Line Items]
U.S. federal statutory tax					35.00%	35.00%	35.00%
Research and development credits (1)	[1]				(3.40%)	(2.90%)	(4.90%)
Amendments to the R&E regulations (2)	[2]						(3.40%)
Tax basis adjustment (3)	[3]					(3.60%)
U.S. manufacturing activity tax benefit					(2.90%)	(1.20%)	(0.60%)
Tax on international activities					(0.60%)	(0.20%)	(0.10%)
Federal audit settlements (4)	[4]					(3.60%)
Other provision adjustments					(0.40%)	0.20%	0.40%
Effective income tax rate					27.70%	23.70%	26.40%
Tax benefits related to reinstatement of research tax credit		$ 235	$ 188
Tax benefit related to issuance of favorable regulations related to R&E expenditures							$ 212
Incremental tax benefit related to tax basis adjustment				$ 265
Tax Year 2007-2008 [Member]
Income Tax Examination [Line Items]
Tax benefit related to settlement of 2007-2008 and 2009-2010 federal tax audit				116
Tax Year 2009-2010 [Member]
Income Tax Examination [Line Items]
Tax benefit related to settlement of 2007-2008 and 2009-2010 federal tax audit				$ 143

[1] In the fourth quarter of 2015 and 2014, we recorded tax benefits of $235 and $188, respectively related to the reinstatement of the research tax credit. Research tax credits for the 2013 and 2012 tax years were both recorded in 2013.

[2] In 2013, we recorded $212 for the issuance of favorable regulations related to research and experimental (R&E) expenditures.

[3] In the second quarter of 2014 we recorded an incremental tax benefit of $265 related to the application of a 2012 Federal Court of Claims decision which held that the tax basis in certain assets could be increased and realized upon the assets' disposition (tax basis adjustment).

[4] In the second quarter of 2014, tax benefits of $116 and $143 were recorded as a result of the 2007-2008 and 2009-2010 federal tax audit settlements.