Employee Benefit Plans (Schedule Of Level 3 Reconciliation) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Balance as of December 31	$ 16,284	$ 14,288
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of December 31	2,096	1,895
Other Benefits [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of December 31	387	362
Other Benefits [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of December 31	1,604	1,440
Other Benefits [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of January 1	93	78
Relating to assets still held at the reporting date	6	7
Relating to assets sold during the period	0	0
Purchases	7	34
Settlements	(1)	(26)
Balance as of December 31	105	93
Pension Plans Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of December 31	14,188	12,393
Pension Plans Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of December 31	3,958	3,203
Pension Plans Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of December 31	8,340	7,467
Pension Plans Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of January 1	1,723	1,409
Relating to assets still held at the reporting date	101	87
Relating to assets sold during the period	4	1
Purchases	79	372
Settlements	(17)	(146)
Balance as of December 31	1,890	1,723
Real Estate [Member] | Other Benefits [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of January 1	38	28
Relating to assets still held at the reporting date	4	3
Relating to assets sold during the period	0	0
Purchases	7	21
Settlements	0	(14)
Balance as of December 31	49	38
Real Estate [Member] | Pension Plans Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of January 1	544
Relating to assets still held at the reporting date	54	49
Relating to assets sold during the period	0	(3)
Purchases	78	352
Settlements	(1)	(139)
Balance as of December 31	675	544
Absolute Return [Member] | Other Benefits [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of January 1	53	49
Relating to assets still held at the reporting date	2	4
Relating to assets sold during the period	0	0
Purchases	0	12
Settlements	0	(12)
Balance as of December 31	55	53
Absolute Return [Member] | Pension Plans Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of January 1		513
Relating to assets still held at the reporting date	23	37
Relating to assets sold during the period	0	4
Purchases	0	0
Settlements	0	0
Balance as of December 31	577
Corporate Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of December 31	1,219
Corporate Fixed Income Securities [Member] | Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of December 31		1,075
Corporate Fixed Income Securities [Member] | Other Benefits [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of December 31	163	137
Corporate Fixed Income Securities [Member] | Other Benefits [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of December 31	1,055	936
Corporate Fixed Income Securities [Member] | Other Benefits [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of January 1	2	1
Relating to assets still held at the reporting date	0	0
Relating to assets sold during the period	0	0
Purchases	0	1
Settlements	(1)	0
Balance as of December 31	1	2
Corporate Fixed Income Securities [Member] | Pension Plans Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of December 31	8,424	7,177
Corporate Fixed Income Securities [Member] | Pension Plans Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of December 31	2,068	1,448
Corporate Fixed Income Securities [Member] | Pension Plans Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of December 31	5,718	5,104
Corporate Fixed Income Securities [Member] | Pension Plans Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance as of January 1	625	611
Relating to assets still held at the reporting date	24	1
Relating to assets sold during the period	4	0
Purchases	1	20
Settlements	(16)	(7)
Balance as of December 31	$ 638	$ 625