Derivative Financial Instruments And Hedging Activities (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	$ 5,258	$ 5,369
Derivative Asset	41	16
Other Assets [Member] | Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	1,688	1,652
Derivative Asset	6	6
Other Assets [Member] | Interest Rate Cap [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	2,082	2,123
Derivative Asset	5	6
Other Assets [Member] | Foreign Currency Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	1,488	1,594
Derivative Asset	30	4
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	7,817	8,475
Derivative Liability	40	46
Other Liabilities [Member] | Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	5,114	5,627
Derivative Liability	35	39
Other Liabilities [Member] | Interest Rate Cap [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	1,764	1,804
Derivative Liability	4	6
Other Liabilities [Member] | Foreign Currency Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	939	1,044
Derivative Liability	$ 1	$ 1