Fair Value (Quantitative Information) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Fair Value Derivative Assets Liabilities Measured On Recurring Basis Unobservable Inputs [Abstract]
Fair Value	$ (73)	$ (60)	$ (4)	$ (8)	$ 16	$ (341)
Interest rate derivatives [Member]
Fair Value Derivative Assets Liabilities Measured On Recurring Basis Unobservable Inputs [Abstract]
Fair Value	(180)	(183)	(101)	(103)	(63)	(412)
Interest rate derivatives [Member] | Minimum [Member]
Fair Value Derivative Assets Liabilities Measured On Recurring Basis Unobservable Inputs [Abstract]
Subsidiaries' credit risk	3.75%
Interest rate derivatives [Member] | Maximum [Member]
Fair Value Derivative Assets Liabilities Measured On Recurring Basis Unobservable Inputs [Abstract]
Subsidiaries' credit risk	6.98%
Interest rate derivatives [Member] | Weighted Average [Member]
Fair Value Derivative Assets Liabilities Measured On Recurring Basis Unobservable Inputs [Abstract]
Subsidiaries' credit risk	5.51%
Foreign Currency Embedded Derivative Argentine Peso [Member]
Fair Value Derivative Assets Liabilities Measured On Recurring Basis Unobservable Inputs [Abstract]
Fair Value	102
Foreign Currency Embedded Derivative Argentine Peso [Member] | Minimum [Member]
Fair Value Derivative Assets Liabilities Measured On Recurring Basis Unobservable Inputs [Abstract]
Argentine Peso to U.S. Dollar currency exchange rate after 1 year	8.84
Foreign Currency Embedded Derivative Argentine Peso [Member] | Maximum [Member]
Fair Value Derivative Assets Liabilities Measured On Recurring Basis Unobservable Inputs [Abstract]
Argentine Peso to U.S. Dollar currency exchange rate after 1 year	36.40
Foreign Currency Embedded Derivative Argentine Peso [Member] | Weighted Average [Member]
Fair Value Derivative Assets Liabilities Measured On Recurring Basis Unobservable Inputs [Abstract]
Argentine Peso to U.S. Dollar currency exchange rate after 1 year	22.12
Foreign Currency Embedded Derivative Euro [Member]
Fair Value Derivative Assets Liabilities Measured On Recurring Basis Unobservable Inputs [Abstract]
Fair Value	(7)
Subsidiaries' credit risk	6.98%
Commodity And Other Derivative Other [Member]
Fair Value Derivative Assets Liabilities Measured On Recurring Basis Unobservable Inputs [Abstract]
Fair Value	$ 12