Long-Term Debt (Scheduled Remaining Maturity Of Long-Term Debt) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
2015	$ 5,733
2016	12,225
2017	17,977
2018	10,296
2019	6,493
2020 and thereafter	12,804
Derivative, Amount of Hedged Item	324	$ 452
Long-term debt	65,852	66,558
Unsecured Debt [Member]
Debt Instrument [Line Items]
2015	1
2016	1,860
2017	4,312
2018	2,834
2019	1,591
2020 and thereafter	8,645
Derivative, Amount of Hedged Item	324	452
Long-term debt	19,567	22,415
Unsecured Debt [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
2015	34
2016	1,934
2017	4,398
2018	2,931
2019	1,625
2020 and thereafter	9,737
Derivative, Amount of Hedged Item	324
Long-term debt	20,983
Unsecured Debt [Member] | Original Issue Discount [Member]
Debt Instrument [Line Items]
2015	(33)
2016	(74)
2017	(86)
2018	(97)
2019	(34)
2020 and thereafter	(1,092)
Derivative, Amount of Hedged Item	0
Long-term debt	(1,416)
Secured Debt [Member]
Debt Instrument [Line Items]
Derivative, Amount of Hedged Item	0	0
Long-term debt	46,285	$ 44,143
Secured Debt [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
2015	5,732
2016	10,365
2017	13,665
2018	7,462
2019	4,902
2020 and thereafter	4,159
Derivative, Amount of Hedged Item	0
Long-term debt	$ 46,285