Accumulated Other Comprehensive Income (Loss) - Reclassification out of Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Interest rate and currency swaps									$ (1,370)		$ (1,777)	$ (2,346)
Derivative loss recognized on termination of hedge relationship									145		(207)	(1,146)
Income (loss) from discontinued operations before income tax	(19)	(29)	(51)	(78)	(99)	55	1,254	350	(249)		2,521	1,380
Other income									(54)		31	101
Net income (loss)	(77)	167	220	226	(295)	(137)	(258)	(155)	536		(845)	(1,408)
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									(15)	[1]
Derivative loss recognized on termination of hedge relationship									(199)	[1]
Total before tax									(214)	[1]
Tax expense (benefit)									(76)	[1]
Net income (loss)									(138)	[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									(15)	[1]
Tax expense (benefit)									(9)	[1]
Net income (loss)									(6)	[1]
Foreign currency translation adjustments [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Sale of Insurance Business [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from discontinued operations before income tax									(24)	[1]
Foreign currency translation adjustments [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Closure of Foreign Legal Entity [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other income									$ 9	[1]

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