Loans And Leases (Schedule Of Activity In The Allowance For Loan Losses) (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
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, Beginning balance	$ 22	$ 80	$ 22	$ 100
Allowance for loan losses, Charge-offs	0	(28)	0	(47)
Allowance for loan losses, Provisions	(1)	2	(1)	1
Allowance for loan losses, Recoveries	1	0	1	0
Allowance for loan losses, Ending balance	22	54	22	54
Institutional [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, Beginning balance	22	31	22	31
Allowance for loan losses, Charge-offs	0	0	0	0
Allowance for loan losses, Provisions	0	(9)	0	(9)
Allowance for loan losses, Recoveries	0	0	0	0
Allowance for loan losses, Ending balance	22	22	22	22
Commercial Real Estate [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, Beginning balance		49		69
Allowance for loan losses, Charge-offs		(28)		(47)
Allowance for loan losses, Provisions	(1)	11	(1)	10
Allowance for loan losses, Recoveries	1	0	1	0
Allowance for loan losses, Ending balance	$ 0	$ 32	$ 0	$ 32

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A valuation allowance for financing receivables that are expected to be uncollectible.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-URI http://asc.fasb.org/extlink&oid=6965416&loc=SL6953423-111524

-Subparagraph (c)(1)

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- Definition

Reduction to the allowance for credit losses related to collections on financing receivables which have been partially or fully charged off as bad debts.

+ References

+ Details

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- Definition

Reduction to the allowance for credit losses related to financing receivables deemed uncollectible.

+ References

+ Details

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- Definition

The sum of the periodic provision charged to earnings, based on an assessment of uncollectibility from the counterparty on account of loan, lease or other credit losses, to reduce these accounts to the amount that approximates their net realizable value.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.11)

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 9

-Section 04

-Paragraph 11

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-DEP

-Chapter 5

-Paragraph 168, 169, 170

-IssueDate 2006-05-01

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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