Accumulated Other Comprehensive Income (Loss) Accumulated Other Compreensive Income (Loss) - Reclassification out of Accumulated OTher Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012	Jun. 30, 2013		Jun. 30, 2012
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Interest rate and currency swaps	$ (353)		$ (467)	$ (732)		$ (966)
Derivative loss recognized on termination of hedge relationship	186		(424)	86		(219)
Income (loss) from discontinued operations before income tax	(76)		2,164	(195)		2,721
Other income (loss)	(55)		5	(78)		(8)
Tax expense (benefit)	(25)		910	(66)		1,117
Net of tax	(51)		1,254	(129)		1,604
Unrealized gains (losses) on cash flow hedging instruments [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Interest rate and currency swaps	(3)	[1]		(9)	[1]
Derivative loss recognized on termination of hedge relationship	0	[1]		(199)	[1]
Total before tax	3	[1]		208	[1]
Tax expense (benefit)	(1)	[1]		(74)	[1]
Net of tax	2	[1]		134	[1]
Foreign currency translation adjustments [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(9)	[1]				15	[1]
Tax expense (benefit)	0	[1]				(9)	[1]
Net of tax	(9)	[1]				6	[1]
Foreign currency translation adjustments [Member] | Sale of Insurance Business [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from discontinued operations before income tax	0	[1]				(24)	[1]
Foreign currency translation adjustments [Member] | Closure of Foreign Legal Entity [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other income (loss)	$ 9	[1]				$ 9	[1]

[1] Amounts in parenthesis indicate expenses recognized in the consolidated statement of income (loss).