Schedule Of Unallocated Items and Eliminations (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Share-based plans	$ (50)	$ (51)
Earnings from operations	2,024	1,788
Pension Plans, Defined Benefit [Member]
Segment Reporting Information [Line Items]
Pension and Postretirement Expense	(334)	(629)
Other Postretirement Benefit Plan, Defined Benefit [Member]
Segment Reporting Information [Line Items]
Pension and Postretirement Expense	(85)	(88)
Unallocated items, eliminations and other [Member]
Segment Reporting Information [Line Items]
Share-based plans	(21)	(23)
Deferred compensation	(50)	16
Amortization of previously capitalized interest	(31)	(30)
Eliminations and other unallocated items	(180)	(129)
Sub-total	(282)	(166)
Pension and Postretirement Expense	315	94
Earnings from operations	33	(72)
Unallocated items, eliminations and other [Member] | Pension Plans, Defined Benefit [Member]
Segment Reporting Information [Line Items]
Pension and Postretirement Expense	255	45
Unallocated items, eliminations and other [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]
Segment Reporting Information [Line Items]
Pension and Postretirement Expense	$ 60	$ 49