Derivative Instruments And Hedging Activities (Fair Value Amounts Of Derivative Instruments Reported On Our Condensed Consolidated Balance Sheet) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 224	$ 233
Derivative Liability, Fair Value, Gross Liability	124	145
Derivative, Notional Amount	53,036	59,116
Accrued Interest [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	15	46
Derivative Liability, Fair Value, Gross Liability	5	12
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	154	126
Derivative Liability, Fair Value, Gross Liability	24	10
Derivative, Notional Amount	10,920	14,340
Interest Rate Swap [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	154	126
Derivative Liability, Fair Value, Gross Liability	18	9
Derivative, Notional Amount	10,698	14,151
Hedge notional amount associated with debt maturing in five or more years	2,100
Foreign Exchange Forward [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	6	1
Derivative, Notional Amount	222	189
Fair Value Hedging [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Receive-fixed Swaps, Fair Value, Gross Asset	142	112
Receive-fixed Swaps, Fair Value, Gross Liability	0	3
Receive-fixed Swaps, Notional Amount	3,900	6,800
Pay-fixed Swaps, Fair Value, Gross Asset	1	13
Pay-fixed Swaps, Fair Value, Gross Liability	18	3
Pay-fixed Swaps, Notional Amount	6,000	6,800
Interest Rate Contract [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	69	105
Derivative Liability, Fair Value, Gross Liability	91	125
Derivative, Notional Amount	41,932	44,466
Foreign Exchange Contract [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	1	0
Derivative Liability, Fair Value, Gross Liability	3	0
Derivative, Notional Amount	159	278
Equity Contract [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	2
Derivative Liability, Fair Value, Gross Liability	6	10
Derivative, Notional Amount	25	32
Interest Rate Swap [Member] \| Interest Rate Contract [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	33	30
Derivative Liability, Fair Value, Gross Liability	55	51
Derivative, Notional Amount	4,979	6,101
Foreign Exchange Forward [Member] \| Foreign Exchange Contract [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	1	0
Derivative Liability, Fair Value, Gross Liability	3	0
Derivative, Notional Amount	159	278
Futures and Forwards [Member] \| Interest Rate Contract [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	3	2
Derivative Liability, Fair Value, Gross Liability	3	2
Derivative, Notional Amount	1,875	1,905
Written Options [Member] \| Interest Rate Contract [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	33	72
Derivative, Notional Amount	17,539	18,220
Written Options [Member] \| Equity Contract [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	0	1
Derivative, Notional Amount	0	0
Purchased Options [Member] \| Interest Rate Contract [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	33	73
Derivative Liability, Fair Value, Gross Liability	0	0
Derivative, Notional Amount	17,539	18,240
Purchased Options [Member] \| Equity Contract [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	2
Derivative Liability, Fair Value, Gross Liability	0	0
Derivative, Notional Amount	0	0
Forward Contracts [Member] \| Equity Contract [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	6	9
Derivative, Notional Amount	25	32
Other Trading [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	70	107
Derivative Liability, Fair Value, Gross Liability	100	135
Derivative, Notional Amount	42,116	44,776
Secured Debt [Member] \| Fair Value Hedging [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Receive-fixed Swaps, Fair Value, Gross Asset	11	1
Receive-fixed Swaps, Fair Value, Gross Liability	0	2
Receive-fixed Swaps, Notional Amount	$ 700	$ 500

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- Definition

Pay-fixed Swaps on portfolios of held-for-investment automotive loan assets, Fair Value, Gross Asset

+ References

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Pay-fixed Swaps on portfolios of held-for-investment automotive loan assets, Fair Value, Gross Liability

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Pay-fixed Swaps on portfolios of held-for-investment automotive loan assets, Fair Value, Notional Amount

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Receive-fixed Swaps on Fixed-rate Debt Obligations, Fair Value, Gross Asset

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Receive-fixed Swaps on Fixed-rate Debt Obligations, Notional Amount

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- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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