Derivative Instruments and Hedging Activities Derivative Instruments and Hedging Activities (Ineffective Portion of Cash Flow Hedges) (Details) - Cash Flow Hedging - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Losses) Recognized in Earnings, Ineffective Portion	$ (6)	$ (4)	$ 43
Interest Expense | Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Losses) Recognized in Earnings, Ineffective Portion	(4)	0	42
Interest Expense | Cross Currency Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Losses) Recognized in Earnings, Ineffective Portion	1	(1)	0
Net Equity In Earnings Of Affiliates | Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Losses) Recognized in Earnings, Ineffective Portion	0	(1)	1
Foreign Currency Gain (Loss) | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Losses) Recognized in Earnings, Ineffective Portion	$ (3)	$ (2)	$ 0