Investment Securities (Details) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Held-to-maturity
Amortized Cost	$ 13,280	$ 1,469
Unrealized Gains	200	14
Unrealized Losses Other than Temporary		(1)
Unrealized Losses Other	(49)	(63)
Fair Value	13,431	1,419
Available-for-sale securities
Amortized Cost	51,870	51,855
Unrealized Gains	1,116	866
Unrealized Losses Other Than Temporary	(254)	(334)
Unrealized Losses Other	(433)	(878)
Fair Value	52,299	51,509
Non-agency [Member] \| Commercial Mortgage Backed Securities [Member]
Held-to-maturity
Amortized Cost	5	10
Unrealized Losses Other	(3)	(5)
Fair Value	2	5
Non-agency [Member] \| Commercial Mortgage Backed Securities [Member]
Available-for-sale securities
Amortized Cost	48	47
Unrealized Gains	3	3
Unrealized Losses Other	(1)
Fair Value	50	50
Agency [Member] \| Residential [Member]
Held-to-maturity
Amortized Cost	10,635	847
Unrealized Gains	162
Unrealized Losses Other	(4)	(4)
Fair Value	10,793	843
Agency [Member] \| Residential [Member]
Available-for-sale securities
Amortized Cost	38,217	37,144
Unrealized Gains	901	718
Unrealized Losses Other	(46)	(159)
Fair Value	39,072	37,703
Agency [Member] \| Commercial Mortgage Backed Securities [Member]
Available-for-sale securities
Amortized Cost	154	194
Unrealized Gains	4	5
Unrealized Losses Other		(2)
Fair Value	158	197
Non agency Prime [Member] \| Residential [Member]
Available-for-sale securities
Amortized Cost	985	1,216
Unrealized Gains	8	12
Unrealized Losses Other Than Temporary	(51)	(86)
Unrealized Losses Other	(46)	(39)
Fair Value	896	1,103
Non agency Non Prime [Member] \| Residential [Member]
Held-to-maturity
Amortized Cost	2	3
Fair Value	2	3
Non agency Non Prime [Member] \| Residential [Member]
Available-for-sale securities
Amortized Cost	1,108	1,193
Unrealized Gains	21	15
Unrealized Losses Other Than Temporary	(198)	(243)
Unrealized Losses Other	(36)	(18)
Fair Value	895	947
Asset backed Securities [Member]
Held-to-maturity
Amortized Cost	119
Available-for-sale securities
Amortized Cost	893
Collateralized Debt Obligations [Member]
Held-to-maturity
Amortized Cost	94	157
Unrealized Gains	15	13
Unrealized Losses Other	(9)	(18)
Fair Value	100	152
Collateralized Debt Obligations [Member]
Available-for-sale securities
Amortized Cost	194	204
Unrealized Gains	37	23
Unrealized Losses Other Than Temporary	(2)	(2)
Unrealized Losses Other	(2)	(1)
Fair Value	227	224
Others [Member]
Held-to-maturity
Amortized Cost	25	127
Unrealized Gains	1
Unrealized Losses Other than Temporary		(1)
Unrealized Losses Other	(7)	(7)
Fair Value	19	119
Others [Member]
Available-for-sale securities
Amortized Cost	699	709
Unrealized Gains	25	23
Unrealized Losses Other Than Temporary	(3)	(3)
Unrealized Losses Other	(9)	(9)
Fair Value	712	720
Obligations of state and political subdivisions [Member]
Held-to-maturity
Amortized Cost	24	27
Unrealized Gains	1	1
Unrealized Losses Other	(1)	(1)
Fair Value	24	27
Available-for-sale securities
Amortized Cost	6,809
Obligations of state and political subdivisions [Member]
Available-for-sale securities
Amortized Cost	6,809	6,835
Unrealized Gains	38	3
Unrealized Losses Other	(165)	(421)
Fair Value	6,682	6,417
Obligations of foreign governments [Member]
Held-to-maturity
Amortized Cost	7	7
Fair Value	7	7
Obligations of foreign governments [Member]
Available-for-sale securities
Amortized Cost	6	6
Fair Value	6	6
U.S. Treasury and agency [Member]
Held-to-maturity
Amortized Cost	2,363	165
Unrealized Gains	21
Unrealized Losses Other		(1)
Fair Value	2,384	164
Available-for-sale securities
Amortized Cost	1,870
U.S. Treasury and agency [Member]
Available-for-sale securities
Amortized Cost	1,870	2,559
Unrealized Gains	7	6
Unrealized Losses Other	(4)	(28)
Fair Value	1,873	2,537
Other Debt Securities [Member]
Held-to-maturity
Amortized Cost	125	126
Unrealized Losses Other	(25)	(27)
Fair Value	100	99
Available-for-sale securities
Amortized Cost	1,436
Other Investments [Member]
Available-for-sale securities
Amortized Cost	216	183
Unrealized Gains	15	17
Unrealized Losses Other		(1)
Fair Value	231	199
Corporate Debt Securities [Member]
Available-for-sale securities
Amortized Cost	1,109	1,109
Unrealized Gains	1
Unrealized Losses Other	(88)	(151)
Fair Value	1,022	958
Perpetual preferred securities [Member]
Available-for-sale securities
Amortized Cost	455	456
Unrealized Gains	56	41
Unrealized Losses Other	(36)	(49)
Fair Value	$ 475	$ 448

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