Pension And Postretirement Benefits (Pension And Postretirement Benefit Costs Included In Operating Expenses) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Net (credit) cost	$ (149)	$ (206)	$ (297)	$ (413)
Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	278	300	556	599
Interest cost on benefit obligation	495	473	990	947
Expected return on assets	(780)	(826)	(1,558)	(1,652)
Amortization of prior service credit	(25)	(26)	(51)	(52)
Net (credit) cost	(32)	(79)	(63)	(158)
Postretirement Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	48	56	96	111
Interest cost on benefit obligation	243	241	486	483
Expected return on assets	(89)	(105)	(178)	(210)
Amortization of prior service credit	(319)	(319)	(638)	(639)
Net (credit) cost	$ (117)	$ (127)	$ (234)	$ (255)