Loans and Leases (Impaired Loans) (Details) (Commercial Real Estate, USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Financing Receivable, Impaired [Line Items]
Recorded investment with no related allowance	$ 130		$ 130		$ 197
Unpaid principal balance with no related allowance recorded	198		198		322
Average recorded investment	148	205	166	222
Interest revenue recognized	10	4	14	8
CRE - property development
Financing Receivable, Impaired [Line Items]
Recorded investment with no related allowance	130		130		197
Unpaid principal balance with no related allowance recorded	143		143		224
Average recorded investment	148	199	166	199
Interest revenue with related allowance recognized	10	4	14	8
CRE - property development - acquired credit impaired
Financing Receivable, Impaired [Line Items]
Recorded investment with no related allowance	0		0		0
Unpaid principal balance with no related allowance recorded	34		34		34
CRE - other - acquired credit impaired
Financing Receivable, Impaired [Line Items]
Recorded investment with no related allowance	0		0		0
Unpaid principal balance with no related allowance recorded	21		21		64
Average recorded investment	0	6	0	23
Interest revenue with related allowance recognized	0	0	0	0
Recorded investment with related allowance	0	0	0	0
Interest revenue with no related allowance recognized	$ 0	$ 0	$ 0	$ 0

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5258-111524

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Amount of interest income, recognized on accrual basis, on financing receivables that are recognized as impaired, for which there is no related allowance for credit losses.

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Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 14A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953550-111524

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