Investment Securities (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Held-to-maturity
Amortized Cost	$ 16,269	$ 1,469
Unrealized Gains	390	14
Unrealized Losses Other than Temporary		(1)
Unrealized Losses Other	(46)	(63)
Fair Value	16,613	1,419
Available-for-sale securities
Amortized Cost	51,492	51,855
Unrealized Gains	1,263	866
Unrealized Losses Other Than Temporary	(277)	(334)
Unrealized Losses Other	(369)	(878)
Fair Value	52,109	51,509
Commercial Mortgage Backed Securities [Member] \| Non-agency [Member]
Held-to-maturity
Amortized Cost	5	10
Unrealized Losses Other	(2)	(5)
Fair Value	3	5
Non-agency [Member] \| Commercial Mortgage Backed Securities [Member]
Available-for-sale securities
Amortized Cost	43	47
Unrealized Gains	2	3
Fair Value	45	50
Residential [Member] \| Agency [Member]
Held-to-maturity
Amortized Cost	13,400	847
Unrealized Gains	339
Unrealized Losses Other	(4)	(4)
Fair Value	13,735	843
Agency [Member] \| Residential [Member]
Available-for-sale securities
Amortized Cost	38,767	37,144
Unrealized Gains	992	718
Unrealized Losses Other	(21)	(159)
Fair Value	39,738	37,703
Agency [Member] \| Commercial Mortgage Backed Securities [Member]
Available-for-sale securities
Amortized Cost	140	194
Unrealized Gains	7	5
Unrealized Losses Other		(2)
Fair Value	147	197
Non-agency Prime [Member] \| Residential [Member]
Available-for-sale securities
Amortized Cost	950	1,216
Unrealized Gains	6	12
Unrealized Losses Other Than Temporary	(48)	(86)
Unrealized Losses Other	(49)	(39)
Fair Value	859	1,103
Residential [Member] \| Non-agency Non-prime [Member]
Held-to-maturity
Amortized Cost	2	3
Unrealized Losses Other	(1)
Fair Value	1	3
Non-agency Non-prime [Member] \| Residential [Member]
Available-for-sale securities
Amortized Cost	1,076	1,193
Unrealized Gains	17	15
Unrealized Losses Other Than Temporary	(224)	(243)
Unrealized Losses Other	(12)	(18)
Fair Value	857	947
Asset backed Securities [Member]
Held-to-maturity
Amortized Cost	84
Asset backed Securities [Member]
Available-for-sale securities
Amortized Cost	882
Collateralized Debt Obligations [Member]
Held-to-maturity
Amortized Cost	60	157
Unrealized Gains	13	13
Unrealized Losses Other	(3)	(18)
Fair Value	70	152
Collateralized Debt Obligations [Member]
Available-for-sale securities
Amortized Cost	189	204
Unrealized Gains	34	23
Unrealized Losses Other Than Temporary	(2)	(2)
Unrealized Losses Other	(3)	(1)
Fair Value	218	224
Other [Member]
Held-to-maturity
Amortized Cost	24	127
Unrealized Gains	1
Unrealized Losses Other than Temporary		(1)
Unrealized Losses Other	(7)	(7)
Fair Value	18	119
Other [Member]
Available-for-sale securities
Amortized Cost	693	709
Unrealized Gains	19	23
Unrealized Losses Other Than Temporary	(3)	(3)
Unrealized Losses Other	(23)	(9)
Fair Value	686	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
Obligations of state and political subdivisions [Member]
Available-for-sale securities
Amortized Cost	6,409	6,835
Unrealized Gains	130	3
Unrealized Losses Other	(40)	(421)
Fair Value	6,499	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	2,623	165
Unrealized Gains	36
Unrealized Losses Other		(1)
Fair Value	2,659	164
U.S. Treasury and agency [Member]
Available-for-sale securities
Amortized Cost	1,477	2,559
Unrealized Gains	12	6
Unrealized Losses Other		(28)
Fair Value	1,489	2,537
Other Debt Securities [Member]
Held-to-maturity
Amortized Cost	124	126
Unrealized Losses Other	(28)	(27)
Fair Value	96	99
Other Investments [Member]
Available-for-sale securities
Amortized Cost	178	183
Unrealized Gains	13	17
Unrealized Losses Other	(1)	(1)
Fair Value	190	199
Corporate Debt Securities [Member]
Available-for-sale securities
Amortized Cost	1,109	1,109
Unrealized Losses Other	(140)	(151)
Fair Value	969	958
Perpetual preferred securities [Member]
Available-for-sale securities
Amortized Cost	455	456
Unrealized Gains	31	41
Unrealized Losses Other	(80)	(49)
Fair Value	$ 406	$ 448

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