Fair Value (Fair Value Measurement - Reconciliation of Level 3 Assets And Liabilities) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Assets, Beginning balance	$ 31	$ 45	$ 40	$ 50
Net realized/unrealized gains (losses) included in earnings, Assets	1	5	3	8
Net realized/unrealized gains (losses) included in other comprehensive income, Assets	0	0	0	0
Purchases, Assets	0	0	0	0
Sales, Assets	2	0	6	0
Issuances, Assets	0	0	0	1
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	(3)	(14)	(18)	(23)
Fair Value, Assets, Ending balance	31	36	31	36
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	1	0	1
Retained Interest [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Assets, Beginning balance	31	42	40	47
Net realized/unrealized gains (losses) included in earnings, Assets	1	4	3	7
Net realized/unrealized gains (losses) included in other comprehensive income, Assets	0	0	0	0
Purchases, Assets	0	0	0	0
Sales, Assets	2	0	6	0
Issuances, Assets	0	0	0	1
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	(3)	(14)	(18)	(23)
Fair Value, Assets, Ending balance	31	32	31	32
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	$ 0	0	$ 0	0
Mortgage Loans Held-for-Sale, Net [Member]
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, Assets, Ending balance		4		4
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)		$ 1		$ 1