Derivative Instruments and Hedging Activities Derivative Instruments and Hedging Activities (Ineffective Portion of Cash Flow Hedges) (Details) (Cash Flow Hedging, USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Losses) Recognized in Earnings, Ineffective Portion	$ (4)	$ 43	$ (4)
Interest Expense | Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Losses) Recognized in Earnings, Ineffective Portion	0	42	(2)
Interest Expense | Cross Currency Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Losses) Recognized in Earnings, Ineffective Portion	(1)	0	(1)
Net Equity In Earnings Of Affiliates | Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Losses) Recognized in Earnings, Ineffective Portion	(1)	1	(1)
Foreign Currency Gain (Loss) | Foreign Exchange Contract
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Losses) Recognized in Earnings, Ineffective Portion	$ (2)	$ 0	$ 0