Derivative Instruments And Hedging Activities (Fair Value Amounts Of Derivative Instruments Reported On Our Condensed Consolidated Balance Sheet) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 214	$ 263
Derivative Liability, Fair Value, Gross Liability	181	252
Notional amount	79,914	81,200
Accrued Interest [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	41	50
Derivative Liability, Fair Value, Gross Liability	15	17
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	87	118
Derivative Liability, Fair Value, Gross Liability	24	7
Notional amount	16,968	18,764
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	81	118
Derivative Liability, Fair Value, Gross Liability	24	7
Notional amount	16,756	18,554
Hedge notional amount associated with debt maturing in five or more years	2,200
Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	6	0
Derivative Liability, Fair Value, Gross Liability	0	0
Notional amount	212	210
Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Receive-fixed Swaps, Fair Value, Gross Asset	75	97
Receive-fixed Swaps, Fair Value, Gross Liability	19	1
Receive-fixed Swaps, Notional Amount	5,300	4,700
Pay-fixed Swaps, Fair Value, Gross Asset	6	21
Pay-fixed Swaps, Fair Value, Gross Liability	5	6
Pay-fixed Swaps, Notional Amount	11,400	13,900
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	126	138
Derivative Liability, Fair Value, Gross Liability	150	161
Notional amount	62,741	60,847
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	1	5
Derivative Liability, Fair Value, Gross Liability	0	78
Notional amount	150	1,514
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	7	6
Notional amount	55	75
Interest Rate Swap [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	37	40
Derivative Liability, Fair Value, Gross Liability	55	65
Notional amount	8,668	11,979
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	5
Derivative Liability, Fair Value, Gross Liability	0	4
Notional amount	150	304
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	4
Derivative Liability, Fair Value, Gross Liability	9	2
Notional amount	18,288	18,886
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	86	94
Notional amount	17,817	14,823
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	2	3
Notional amount	1	1
Purchased Options [Member] | Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	86	94
Derivative Liability, Fair Value, Gross Liability	0	0
Notional amount	17,968	15,159
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
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	5	3
Notional amount	54	74
Swap [Member] | Foreign Exchange 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	74
Notional amount	0	1,210
Other Trading [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	127	145
Derivative Liability, Fair Value, Gross Liability	157	245
Notional amount	$ 62,946	$ 62,436