Fair Value (Schedule Of Fair Value Measurements, Assets, Using Significant Unobservable Inputs) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets	$ 6,820	$ 6,859	$ 8,691	$ 5,761
Transfers into Level 3, Assets	95	114	116	114
Transfers out of Level 3, Assets	(1,188)	(1,220)	(4,218)	(2,047)
Recorded in Revenue, Assets	3	172	108	247
Recorded in Other Comprehensive Income, Assets	(3)	4	12	59
Purchases, Assets	1,691	1,876	3,094	3,995
Issuances, Assets	0	0	0	0
Sales, Assets	0	(2)	(73)	(3)
Settlements, Assets	(487)	(402)	(799)	(725)
Fair Value, ending balance, Assets	6,931	7,401	6,931	7,401
Change in Unrealized Gains (Losses) Related to Financial Instruments, Assets, Held at Period End	(52)	(30)	(73)	(51)
Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets	6,693	6,624	8,513	5,507
Transfers into Level 3, Assets	95	114	116	114
Transfers out of Level 3, Assets	(1,188)	(1,220)	(4,218)	(2,047)
Recorded in Revenue, Assets	80	210	226	354
Recorded in Other Comprehensive Income, Assets	(3)	4	12	59
Purchases, Assets	1,534	1,780	2,896	3,831
Issuances, Assets
Sales, Assets			(74)
Settlements, Assets	(440)	(320)	(700)	(626)
Fair Value, ending balance, Assets	6,771	7,192	6,771	7,192
US Treasury and Federal Agencies, Direct Obligations [Member] | Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Purchases, Assets		17		17
Fair Value, ending balance, Assets		17		17
US Treasury and Federal Agencies, Mortgage-backed Securities [Member] | Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets	912	898	1,189	673
Transfers into Level 3, Assets	50		50
Transfers out of Level 3, Assets			(251)	(404)
Recorded in Other Comprehensive Income, Assets				1
Purchases, Assets		62		699
Settlements, Assets	(29)	(28)	(55)	(37)
Fair Value, ending balance, Assets	933	932	933	932
Asset-backed Securities, Student Loans [Member] | Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets	511	1,308	860	1,234
Transfers into Level 3, Assets			0
Transfers out of Level 3, Assets		(308)	(341)	(341)
Recorded in Revenue, Assets	1	1	1	3
Recorded in Other Comprehensive Income, Assets	(8)	(1)	(10)	0
Purchases, Assets		300		421
Settlements, Assets	(20)	(11)	(26)	(28)
Fair Value, ending balance, Assets	484	1,289	484	1,289
Asset-backed Securities, Credit Cards [Member] | Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets	119	75	91	43
Transfers into Level 3, Assets	0		21
Transfers out of Level 3, Assets		(15)	0	(16)
Recorded in Revenue, Assets	2	1	3	2
Recorded in Other Comprehensive Income, Assets	(4)	0	(3)	(2)
Purchases, Assets	157	19	224	51
Sales, Assets			(62)
Settlements, Assets	0	(1)	0	1
Fair Value, ending balance, Assets	274	79	274	79
Asset-backed Securities, Other [Member] | Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets	3,090	2,248	2,798	2,000
Transfers into Level 3, Assets	0	114	0	114
Transfers out of Level 3, Assets		(135)	0	(135)
Recorded in Revenue, Assets	11	9	21	16
Recorded in Other Comprehensive Income, Assets	9	3	25	49
Purchases, Assets	213	295	569	570
Sales, Assets			(12)
Settlements, Assets	(229)	(4)	(307)	(84)
Fair Value, ending balance, Assets	3,094	2,530	3,094	2,530
Asset-backed Securities [Member] | Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets	3,720	3,631	3,749	3,277
Transfers into Level 3, Assets	0	114	21	114
Transfers out of Level 3, Assets		(458)	(341)	(492)
Recorded in Revenue, Assets	14	11	25	21
Recorded in Other Comprehensive Income, Assets	(3)	2	12	47
Purchases, Assets	370	614	793	1,042
Issuances, Assets
Sales, Assets			(74)
Settlements, Assets	(249)	(16)	(333)	(111)
Fair Value, ending balance, Assets	3,852	3,898	3,852	3,898
Non-US Debt Securities, Mortgage-Backed Securities [Member] | Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets	469	682	1,457	396
Transfers into Level 3, Assets	0			0
Transfers out of Level 3, Assets	(338)	(506)	(1,495)	(702)
Recorded in Revenue, Assets	0	0	0	0
Recorded in Other Comprehensive Income, Assets	3	0	4	0
Purchases, Assets	147	182	306	653
Issuances, Assets
Sales, Assets			0
Settlements, Assets	(8)	3	1	14
Fair Value, ending balance, Assets	273	361	273	361
Non-US Debt Securities, Asset-Backed Securities [Member] | Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets	1,035	1,125	1,768	740
Transfers into Level 3, Assets	0			0
Transfers out of Level 3, Assets	(483)	(60)	(1,568)	(120)
Recorded in Revenue, Assets	0	0	0	0
Recorded in Other Comprehensive Income, Assets	1	1	0	12
Purchases, Assets	840	761	1,207	1,253
Issuances, Assets
Sales, Assets			0
Settlements, Assets	(31)	(78)	(45)	(136)
Fair Value, ending balance, Assets	1,362	1,749	1,362	1,749
Non-US Debt Securities, Government Securities [Member] | Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets				1
Transfers into Level 3, Assets				0
Transfers out of Level 3, Assets				0
Recorded in Revenue, Assets				0
Recorded in Other Comprehensive Income, Assets				0
Purchases, Assets				0
Issuances, Assets
Sales, Assets
Settlements, Assets				(1)
Fair Value, ending balance, Assets		0		0
Non-US Debt Securities, Other [Member] | Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets	314	6	71	8
Transfers into Level 3, Assets	0			0
Transfers out of Level 3, Assets	(308)	0	(372)	0
Recorded in Revenue, Assets	0	0		0
Recorded in Other Comprehensive Income, Assets	(4)	0	(4)	(1)
Purchases, Assets	0	0	308	0
Issuances, Assets
Sales, Assets			0
Settlements, Assets	(1)	0	(2)	(1)
Fair Value, ending balance, Assets	1	6	1	6
Non U S Debt Securities [Member] | Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets	1,818	1,813	3,296	1,145
Transfers into Level 3, Assets	0			0
Transfers out of Level 3, Assets	(1,129)	(566)	(3,435)	(822)
Recorded in Revenue, Assets	0	0	0	0
Recorded in Other Comprehensive Income, Assets	0	1	0	11
Purchases, Assets	987	943	1,821	1,906
Issuances, Assets
Sales, Assets			0
Settlements, Assets	(40)	(75)	(46)	(124)
Fair Value, ending balance, Assets	1,636	2,116	1,636	2,116
State And Political Subdivisions [Member] | Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets	50	51	50	50
Transfers into Level 3, Assets			0	0
Transfers out of Level 3, Assets		0	0	0
Recorded in Revenue, Assets	0	0	0	0
Recorded in Other Comprehensive Income, Assets	0	1	0	2
Purchases, Assets	0	2	0	2
Sales, Assets			0
Settlements, Assets	(1)	0	(1)	0
Fair Value, ending balance, Assets	49	54	49	54
Collateralized Mortgage Obligations [Member] | Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets	193	228	227	359
Transfers into Level 3, Assets	45		45	0
Transfers out of Level 3, Assets	(59)	(196)	(191)	(329)
Recorded in Revenue, Assets	66	199	201	333
Recorded in Other Comprehensive Income, Assets	0	0	0	(2)
Purchases, Assets	177	142	282	165
Sales, Assets			0
Settlements, Assets	(121)	(200)	(263)	(353)
Fair Value, ending balance, Assets	301	173	301	173
Other U.S. Debt Securities [Member] | Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets		3	2	3
Transfers into Level 3, Assets			0	0
Transfers out of Level 3, Assets		0	0	0
Recorded in Revenue, Assets		0	0	0
Recorded in Other Comprehensive Income, Assets		0	0	0
Purchases, Assets		0	0	0
Sales, Assets			0
Settlements, Assets		(1)	(2)	(1)
Fair Value, ending balance, Assets	0	2	0	2
Foreign Exchange Contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets	127	227	168	254
Transfers into Level 3, Assets			0	0
Transfers out of Level 3, Assets		0	0	0
Recorded in Revenue, Assets	(77)	(37)	(108)	(104)
Recorded in Other Comprehensive Income, Assets	0	0	0	0
Purchases, Assets	157	96	198	154
Sales, Assets		(2)	0	(3)
Settlements, Assets	(47)	(82)	(98)	(99)
Fair Value, ending balance, Assets	160	202	160	202
Change in Unrealized Gains (Losses) Related to Financial Instruments, Assets, Held at Period End	(52)	(29)	(73)	(59)
Interest Rate Contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets		8	10	0
Transfers into Level 3, Assets			0	0
Transfers out of Level 3, Assets		0	0	0
Recorded in Revenue, Assets		(1)	(10)	(3)
Recorded in Other Comprehensive Income, Assets		0	0
Purchases, Assets		0	0	10
Sales, Assets		0	1	0
Settlements, Assets		0	(1)	0
Fair Value, ending balance, Assets	0	7	0	7
Change in Unrealized Gains (Losses) Related to Financial Instruments, Assets, Held at Period End		(1)	0	8
Derivative Financial Instruments, Assets [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning balance, Assets		235	178	254
Transfers into Level 3, Assets			0
Transfers out of Level 3, Assets		0	0	0
Recorded in Revenue, Assets		(38)	(118)	(107)
Recorded in Other Comprehensive Income, Assets		0	0	0
Purchases, Assets		96	198	164
Issuances, Assets
Sales, Assets		(2)	1	(3)
Settlements, Assets		(82)	(99)	(99)
Fair Value, ending balance, Assets	160	209	160	209
Change in Unrealized Gains (Losses) Related to Financial Instruments, Assets, Held at Period End		$ (30)	$ (73)	$ (51)