Retirement Plans (Net Periodic Pension Expense For Qualified And Nonqualified U.S. Defined Benefit Plans) (Details) - USD ($) $ in Millions	3 Months Ended					12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	$ 424	$ 376
Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost						$ 153	$ 160	$ 158
Interest cost						467	536	580
Expected return on plan assets						(765)	(774)	(815)
Amortization of Gains (Losses)						337	339	400
Amortization of prior service cost						16	28	41
Recognized Net Gain (Loss) Due to Curtailments						0	23	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement			$ 3	$ 3	$ 439	424	383	445
Defined Benefit Plan, Other Cost (Credit)						0	22	0
Net periodic pension expense						632	717	809
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost						5	4	4
Interest cost						8	9	9
Expected return on plan assets						(11)	(11)	(10)
Amortization of Gains (Losses)						2	2	1
Amortization of prior service cost						0	0	0
Recognized Net Gain (Loss) Due to Curtailments						0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement						0	1	0
Defined Benefit Plan, Other Cost (Credit)						0	0	0
Net periodic pension expense						$ 4	$ 5	$ 4