Segment and Revenue Information (Schedule Of Revenue from External Customers Attributed to Foreign Countries by Geographic Area) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 28,341	$ 25,146	$ 24,258	$ 23,382	$ 24,770	$ 24,223	$ 23,051	$ 21,961	$ 101,127	$ 94,005	$ 93,496
Non-U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									56,451	50,299	53,189
Asia, Other Than China
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									12,141	9,195	9,892
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									12,976	11,240	13,018
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									13,764	11,932	10,289
Middle East
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									9,745	11,433	12,251
Oceania
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									2,298	1,931	1,693
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									2,583	2,212	2,084
Africa
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									1,486	815	1,990
Latin America, Caribbean And Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									1,458	1,541	1,972
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									$ 44,676	$ 43,706	$ 40,307