Investment Securities (Summary) (Details) (USD $) In Millions	6 Months Ended	12 Months Ended
Jun. 30, 2011	Dec. 31, 2010
Securities available for sale, amortized cost	$ 49,851	$ 58,171
Securities available for sale, unrealized gains	1,199	1,115
Securities available for sale, unrealized losses	(1,383)	(1,976)
Securities available for sale, fair value	49,667	57,310
Held-to-maturity securities, amortized cost	9,747	6,952
Held-to-maturity securities, unrealized gains	180	230
Held-to-maturity securities, unrealized losses	(17)	(5)
Held-to-maturity securities, fair value	9,910	7,177
Commercial Mortgage-backed Non-agency [Member]
Securities available for sale, amortized cost	2,494	1,794
Securities available for sale, unrealized gains	63	73
Securities available for sale, unrealized losses	(12)	(11)
Securities available for sale, fair value	2,545	1,856
Held-to-maturity securities, amortized cost	4,027	4,316
Held-to-maturity securities, unrealized gains	147	178
Held-to-maturity securities, unrealized losses	(2)	(4)
Held-to-maturity securities, fair value	4,172	4,490
Asset backed [Member]
Held-to-maturity securities, amortized cost		2,626
Asset backed [Member]
Securities available for sale, amortized cost	3,839	2,780
Securities available for sale, unrealized gains	37	40
Securities available for sale, unrealized losses	(191)	(238)
Securities available for sale, fair value	3,685	2,582
Held-to-maturity securities, amortized cost	2,063
Held-to-maturity securities, unrealized gains	31	51
Held-to-maturity securities, unrealized losses	(2)	(1)
Held-to-maturity securities, fair value	2,092	2,676
Other Debt Securities [Member]
Securities available for sale, amortized cost		3,992
Other Debt Securities [Member]
Securities available for sale, amortized cost	3,343
Securities available for sale, unrealized gains	111	102
Securities available for sale, unrealized losses	(12)	(17)
Securities available for sale, fair value	3,442	4,077
Held-to-maturity securities, amortized cost	366	10
Held-to-maturity securities, unrealized gains		1
Held-to-maturity securities, unrealized losses	(3)
Held-to-maturity securities, fair value	363	11
Debt Securities [Member]
Securities available for sale, amortized cost	49,545	57,793
Securities available for sale, unrealized gains	1,199	1,115
Securities available for sale, unrealized losses	(1,383)	(1,976)
Securities available for sale, fair value	49,361	56,932
US Treasury and Government Agencies Securities [Member]
Securities available for sale, amortized cost	3,954	5,575
Securities available for sale, unrealized gains	188	157
Securities available for sale, unrealized losses	(12)	(22)
Securities available for sale, fair value	4,130	5,710
Residential Mortgage-backed Agency [Member]
Securities available for sale, amortized cost	25,126	31,697
Securities available for sale, unrealized gains	479	443
Securities available for sale, unrealized losses	(105)	(420)
Securities available for sale, fair value	25,500	31,720
Held-to-maturity securities, amortized cost	2,775
Held-to-maturity securities, unrealized gains	1
Held-to-maturity securities, unrealized losses	(8)
Held-to-maturity securities, fair value	2,768
Residential Mortgage-backed Non-agency [Member]
Securities available for sale, amortized cost	7,232	8,193
Securities available for sale, unrealized gains	220	230
Securities available for sale, unrealized losses	(998)	(1,190)
Securities available for sale, fair value	6,454	7,233
Commercial Mortgage-backed Agency [Member]
Securities available for sale, amortized cost	1,276	1,763
Securities available for sale, unrealized gains	28	40
Securities available for sale, unrealized losses	(1)	(6)
Securities available for sale, fair value	1,303	1,797
Held-to-maturity securities, amortized cost	508
Held-to-maturity securities, unrealized losses	(2)
Held-to-maturity securities, fair value	506
State and Municipal [Member]
Securities available for sale, amortized cost	2,281	1,999
Securities available for sale, unrealized gains	73	30
Securities available for sale, unrealized losses	(52)	(72)
Securities available for sale, fair value	2,302	1,957
Held-to-maturity securities, amortized cost	8
Held-to-maturity securities, unrealized gains	1
Held-to-maturity securities, fair value	9
Corporate Stocks and Other [Member]
Securities available for sale, amortized cost	306	378
Securities available for sale, fair value	$ 306	$ 378

For an unclassified balance sheet, this item represents investments in debt and equity securities which are categorized neither as held-to-maturity nor trading. Such securities are reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale Security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain or loss of an Available-for-sale Security that is designated as being hedged in a fair value hedge shall be recognized in earnings during the period of the hedge, as should other than temporary declines in fair value below costs basis.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 16

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 133
-Paragraph 22

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 12
-Subparagraph b

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 13

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 14

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Balance Type:	debit
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- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Staff Position (FSP)
-Number FAS115-1/124-1
-Paragraph 7
-Footnote 2

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 19

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- Definition

This item represents the gross unrealized gains for securities which are categorized neither as held-to-maturity nor trading securities. Such gross unrealized gains are the excess of the fair value of the Available-for-sale Securities over their carrying value as of the reporting date. Such gross unrealized gains are included in other comprehensive income in the statement of shareholders' equity, unless the Available-for-sale Security is designated as a hedge. All or a portion of the unrealized holding gain of an available-for-sale security that is designated as being hedged in a fair value hedge shall be recognized in earnings during the period of the hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 133
-Paragraph 22

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 13, 19

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- Definition

This item represents the gross unrealized losses for securities which are categorized neither as held-to-maturity nor trading securities. Such gross unrealized losses are the excess of the carrying value of the Available-for-sale Securities over their fair value as of the reporting date. Such gross unrealized losses are included in other comprehensive income in the statement of shareholders' equity, unless the Available-for-sale Security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding loss of an Available-for-sale Security that is designated as being hedged in a fair value hedge shall be recognized in earnings during the period of the hedge, as should other than temporary declines in fair value below costs basis.

+ References

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- Definition

For an unclassified balance sheet, this item represents investments in debt securities which are categorized as held-to-maturity; such investments are measured at amortized cost (carrying value). The held-to-maturity category is for those securities that the Entity has the positive intent and ability to hold until maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 43
-Chapter 3
-Section A
-Paragraph 4, 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 17

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 7, 8, 9, 10, 11

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

This item represents the aggregate fair value of investments in debt securities as of the balance sheet date and which are categorized as held-to-maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 19

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 137

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- Definition

As of the balance sheet date, the excess of fair value over carrying value (amortized cost) of a debt security categorized as held-to-maturity, exclusive of dividend or interest income recognized but not yet received and exclusive of any write-downs for other-than-temporary impairment. Such item represents the gross unrecognized holding gain.

+ References

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- Definition

As of the balance sheet date, the excess of carrying value (amortized cost) over fair value of a debt security categorized as held-to-maturity, exclusive of dividend or interest income recognized but not yet received and exclusive of any write-downs for other-than-temporary impairment. Such item represents the gross unrecognized holding loss.

+ References

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