Derivative Financial Instruments And Hedging Activities (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	$ 9,025	$ 5,369
Derivative Asset	36	16
Other Assets [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	3,166	1,652
Derivative Asset	6	6
Other Assets [Member] | Interest Rate Caps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	4,380	2,123
Derivative Asset	8	6
Other Assets [Member] | Foreign Currency Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	1,479	1,594
Derivative Asset	22	4
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	10,756	8,475
Derivative Liability	32	46
Other Liabilities [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	6,775	5,627
Derivative Liability	24	39
Other Liabilities [Member] | Interest Rate Caps [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	3,981	1,804
Derivative Liability	8	6
Other Liabilities [Member] | Foreign Currency Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	0	1,044
Derivative Liability	$ 0	$ 1