Fair Value (Fair Value Measurement - Reconciliation of Level 3 Assets And Liabilities) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	$ 1	$ 0	$ 1	$ 0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Assets, Beginning balance	45	84	50	99
Net realized/unrealized gains (losses) included in earnings, Assets	5	4	8	5
Net realized/unrealized gains (losses) included in other comprehensive income, Assets	0	0	0	0
Purchases, Assets	0	0	0	0
Sales, Assets	0	0	0	0
Issuances, Assets	0	0	1	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	(14)	(14)	(23)	(33)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	0	0	3
Fair Value, Assets, Ending balance	36	74	36	74
Loans Held-for-Sale [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	1		1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Assets, Beginning balance	3		3
Net realized/unrealized gains (losses) included in earnings, Assets	1		1
Net realized/unrealized gains (losses) included in other comprehensive income, Assets	0		0
Purchases, Assets	0		0
Sales, Assets	0		0
Issuances, Assets	0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0		0
Fair Value, Assets, Ending balance	4		4
Retained Interest [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Assets, Beginning balance	42	84	47	100
Net realized/unrealized gains (losses) included in earnings, Assets	4	4	7	5
Net realized/unrealized gains (losses) included in other comprehensive income, Assets	0	0	0	0
Purchases, Assets	0	0	0	0
Sales, Assets	0	0	0	0
Issuances, Assets	0	0	1	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	(14)	(14)	(23)	(31)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	0	0	0
Fair Value, Assets, Ending balance	$ 32	74	$ 32	74
Interest Rate Contract [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)				0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Net Derivative Asset (Liability), Beginning balance				(1)
Gain (Loss) Included in Earnings, Net Derivative Asset (Liability)				0
Gain (Loss) Included in Other Comprehensive Income (Loss), Net Derivative Asset (Liability)				0
Purchases, Net Derivative Asset (Liability)				0
Sales, Net Derivative Asset (Liability)				0
Issuances, Net Derivative Asset (Liability)				0
Settlements, Net Derivative Asset (Liability)				(2)
Transfers out of Level 3, Net Derivative Asset (Liability)				3
Fair Value, Net Derivative Asset (Liability), Ending balance		$ 0		$ 0