Derivative Financial Instruments And Hedging Activities (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	$ 5,394	$ 5,369
Derivative Asset	10	16
Other Assets [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	2,845	1,652
Derivative Asset	6	6
Other Assets [Member] | Interest Rate Caps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	2,549	2,123
Derivative Asset	4	6
Other Assets [Member] | Foreign Currency Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	0	1,594
Derivative Asset	0	4
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	9,525	8,475
Derivative Liability	44	46
Other Liabilities [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	5,961	5,627
Derivative Liability	24	39
Other Liabilities [Member] | Interest Rate Caps [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	2,197	1,804
Derivative Liability	3	6
Other Liabilities [Member] | Foreign Currency Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	1,367	1,044
Derivative Liability	$ 17	$ 1