Postretirement Plans (Reconciliation Of Level 3 Assets Held) (Details) (Pension Plans [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance at fair value	$ 58,131	$ 56,178
Net Realized and Unrealized Gains/(Losses)	5,893	3,316
Net Purchases, Issuances and Settlements	(640)	(103)
Ending balance at fair value	61,119	58,131
Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance at fair value	8,026	7,745
Net Realized and Unrealized Gains/(Losses)	761	1,066
Net Purchases, Issuances and Settlements	(298)	(870)
Net Transfers Into/(Out of) Level 3	(149)	85
Ending balance at fair value	8,340	8,026
Fixed Income Securities [Member] | Corporate [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance at fair value	17,488
Fixed Income Securities [Member] | Corporate [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance at fair value	19
Net Purchases, Issuances and Settlements	(7)
Net Transfers Into/(Out of) Level 3	(10)
Ending balance at fair value	2
Fixed Income Securities [Member] | Mortgage backed, Asset backed and other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance at fair value	1,207
Fixed Income Securities [Member] | Mortgage backed, Asset backed and other | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance at fair value	554
Net Realized and Unrealized Gains/(Losses)	14
Net Purchases, Issuances and Settlements	10
Net Transfers Into/(Out of) Level 3	33
Ending balance at fair value	611
Fixed Income Securities [Member] | Corporate and other [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance at fair value		15,262
Fixed Income Securities [Member] | Corporate and other [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance at fair value		3
Net Realized and Unrealized Gains/(Losses)
Net Purchases, Issuances and Settlements		16
Net Transfers Into/(Out of) Level 3		5
Ending balance at fair value		24
Fixed Income Securities [Member] | Mortgage backed and asset backed [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance at fair value		1,040
Fixed Income Securities [Member] | Mortgage backed and asset backed [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance at fair value		561
Net Realized and Unrealized Gains/(Losses)
Net Purchases, Issuances and Settlements		(11)
Net Transfers Into/(Out of) Level 3		(1)
Ending balance at fair value		549
Fixed Income Securities [Member] | Other [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance at fair value	498	484
Fixed Income Securities [Member] | Other [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance at fair value	255
Net Realized and Unrealized Gains/(Losses)	24
Net Purchases, Issuances and Settlements	(27)
Ending balance at fair value	252
Fixed Income Securities [Member] | Common Or Collective Or Pooled Funds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance at fair value	2,127	2,538
Fixed Income Securities [Member] | Municipal [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance at fair value	1,636	1,722
Fixed Income Securities [Member] | Municipal [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance at fair value		245
Net Realized and Unrealized Gains/(Losses)		37
Net Purchases, Issuances and Settlements		(27)
Net Transfers Into/(Out of) Level 3
Ending balance at fair value		255
Equity securities [Member] | Non United States Common And Preferred Stock [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance at fair value	7,151	7,722
Equity securities [Member] | Non United States Common And Preferred Stock [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance at fair value	1
Net Purchases, Issuances and Settlements	(1)
Net Transfers Into/(Out of) Level 3	1	1
Ending balance at fair value	1	1
Equity securities [Member] | Common Or Collective Or Pooled Funds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance at fair value	2,658	3,239
Equity securities [Member] | Common Or Collective Or Pooled Funds [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net Realized and Unrealized Gains/(Losses)	(24)
Net Purchases, Issuances and Settlements	193
Ending balance at fair value	169
Private Equity Funds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance at fair value	2,955
Private Equity Funds [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance at fair value	2,958
Net Realized and Unrealized Gains/(Losses)	415
Net Purchases, Issuances and Settlements	(446)
Ending balance at fair value	2,927
Real estate and real assets [Member] | Real Estate [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance at fair value	3,199	2,865
Real estate and real assets [Member] | Real Estate [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance at fair value	2,424	2,128
Net Realized and Unrealized Gains/(Losses)	336	232
Net Purchases, Issuances and Settlements	(107)	64
Ending balance at fair value	2,653	2,424
Real estate and real assets [Member] | Real assets [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance at fair value	1,567	1,506
Real estate and real assets [Member] | Real assets [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance at fair value	706	664
Net Realized and Unrealized Gains/(Losses)	32	78
Net Purchases, Issuances and Settlements	26	(36)
Ending balance at fair value	764	706
Hedge Funds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance at fair value	3,372	2,776
Hedge Funds [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance at fair value	1,109	1,473
Net Realized and Unrealized Gains/(Losses)	(36)	183
Net Purchases, Issuances and Settlements	61	(627)
Net Transfers Into/(Out of) Level 3	(173)	80
Ending balance at fair value	961	1,109
Private Equity and Other Funds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance at fair value		2,968
Private Equity and Other Funds [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance at fair value		2,671
Net Realized and Unrealized Gains/(Losses)		536
Net Purchases, Issuances and Settlements		(249)
Ending balance at fair value		$ 2,958