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		9 Months Ended	12 Months Ended
		Dec. 31, 2017	Sep. 30, 2016	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Examination [Line Items]
U.S. federal statutory tax					21.00%	35.00%	35.00%
Foreign derived intangible income	[1]				(4.70%)
Federal audit settlements	[2]				(3.60%)		(3.10%)
Research and development credits					(1.80%)	(1.60%)	(5.00%)
Excess tax benefits	[3]				(1.60%)	(2.10%)	(1.80%)
Other provision adjustments					1.30%	(0.20%)	(0.30%)
Impact of Tax Cuts and Jobs Act	[4]				(1.00%)	(12.60%)
Tax on non-US activities					0.30%	(0.90%)	(0.50%)
Tax basis adjustment	[5]						(7.60%)
U.S. manufacturing activity tax benefit						(1.30%)	(3.70%)
Effective income tax rate					9.90%	16.30%	13.00%
Effective Income Tax Reconciliation change in tax benefit due to TCJA					$ 549
Excess tax benefits related to employee share-based payments					181	$ 207	$ 105
Effective Income Tax Rate Reconciliation, Impact of tax reform legislation, Amount		$ 1,271
Incremental tax benefit related to tax basis adjustment			$ 440
Tax Year 2013-2014 [Member]
Income Tax Examination [Line Items]
Tax benefit related to settlement of federal tax audit				$ (412)
Tax Year 2011-2012 [Member]
Income Tax Examination [Line Items]
Tax benefit related to settlement of federal tax audit			$ (177)
Reduction in Taxes [Member]
Income Tax Examination [Line Items]
Effective Income Tax Rate Reconciliation, Impact of tax reform legislation, Amount		$ 1,430
Foreign Tax Authority [Member] | Reduction in Taxes [Member]
Income Tax Examination [Line Items]
Effective Income Tax Rate Reconciliation, Impact of tax reform legislation, Amount					$ (159)

[1] On December 22, 2017, the Tax Cuts and Jobs Act (TCJA) was enacted. The TCJA revised the U.S. corporate income tax by, among other things, lowering the rate from 35% to 21% effective January 1, 2018, implementing a territorial tax system and imposing a one-time tax on deemed repatriated earnings of non-U.S. subsidiaries. The TCJA also enacted provisions which effectively apply a lower U.S. tax rate to intangible income derived from serving non-U.S. markets. In 2018, we recorded a $549 tax benefit related to foreign derived intangible income.

[2] In the third quarter of 2018, we recorded a tax benefit of $412 related to the settlement of the 2013-2014 federal tax audit. In the third quarter of 2016, a tax benefit of $177 was recorded related to the settlement of the 2011-2012 federal tax audit.

[3] In 2018, 2017 and 2016, we recorded excess tax benefits related to employee share-based payments of $181, $207 and $105.

[4] In accordance with U.S. Securities and Exchange Commission Staff Accounting Bulletin No. 118 (SAB 118), in the fourth quarter of 2017, we recorded provisional tax benefits of $1,430 related to the remeasurement of our net U.S. deferred tax liabilities to reflect the reduction in the corporate tax rate and a provisional tax expense of $159 related to tax on non-U.S. activities resulting from the TCJA. During the fourth quarter of 2018 and in accordance with SAB 118, the Company completed its accounting for the provisional amounts recognized at December 31, 2017 and recorded an incremental benefit related to refinements to these provisional amounts which was not significant.

[5] In the third quarter of 2016, we recorded incremental tax benefits of $440 related to the application of a 2012 Federal Court of Claims decision which held that the tax basis in certain assets could be increased (tax basis adjustment).