Accumulated Other Comprehensive Income (Loss) - Reclassification out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Interest rate and currency swaps										$ (895)	$ (1,058)	$ (1,370)
Derivative loss recognized on termination of hedge relationship										(97)	(303)	145
Net income (loss)		$ (173)	$ (37)	$ (216)	$ (5)	$ 36	$ 152	$ 229	$ 106	(431)	523	536
Income (loss) from discontinued operations before income tax										(54)	(27)	(249)
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	[1]									(13)	(11)	(15)
Derivative loss recognized on termination of hedge relationship	[1]											(199)
Total before tax	[1]									(13)	(11)	(214)
Tax benefit	[1]									(5)	(4)	(76)
Net income (loss)	[1]									$ (8)	$ (7)	(138)
Accumulated Translation Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	[1]											(15)
Tax benefit	[1]											(9)
Net income (loss)	[1]											(6)
Sale of Insurance Business [Member] | Accumulated Translation Adjustment [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	[1]											(24)
Closure of Foreign Legal Entity [Member] | Accumulated Translation Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other Income	[1]											$ 9

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