Postretirement Plans (Reconciliation Of Level 3 Assets Held) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Ending balance at fair value	$ 50,614	$ 48,886
Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance at fair value	6,468	4,667
Net Realized and Unrealized Gains/(Losses)	529	626
Net Purchases, Issuances and Settlements	778	1,179
Net Transfers Into/(Out of) Level 3	2	(4)
Ending balance at fair value	7,777	6,468
Corporate [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance at fair value	4	5
Net Purchases, Issuances and Settlements	6	(1)
Net Transfers Into/(Out of) Level 3	1
Ending balance at fair value	11	4
Mortgage Backed And Asset Backed [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance at fair value	33	23
Net Realized and Unrealized Gains/(Losses)	2	(1)
Net Purchases, Issuances and Settlements	(25)	15
Net Transfers Into/(Out of) Level 3	1	(4)
Ending balance at fair value	11	33
Other Debt Securities [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net Purchases, Issuances and Settlements	3
Ending balance at fair value	3
Private Equity [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance at fair value	2,626	2,291
Net Realized and Unrealized Gains/(Losses)	327	379
Net Purchases, Issuances and Settlements	(94)	(44)
Ending balance at fair value	2,859	2,626
Real Estate And Real Assets [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance at fair value	1,818	1,337
Net Realized and Unrealized Gains/(Losses)	246	157
Net Purchases, Issuances and Settlements	303	324
Ending balance at fair value	2,367	1,818
Global Strategies [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance at fair value	69
Net Realized and Unrealized Gains/(Losses)	6	(1)
Net Purchases, Issuances and Settlements		70
Ending balance at fair value	75	69
Hedge Funds [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance at fair value	1,918	1,011
Net Realized and Unrealized Gains/(Losses)	(52)	92
Net Purchases, Issuances and Settlements	585	815
Ending balance at fair value	$ 2,451	$ 1,918