Loans and Leases (Narrative) (Details) (USD $)	9 Months Ended	12 Months Ended
Sep. 30, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, allowance for losses	$ 22,000,000	$ 22,000,000
Aggregate short-duration advances	4,650,000,000	3,300,000,000
Loans modified in troubled debt restructurings	0	0
Commercial and Financial
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, allowance for losses	0
Institutional
Financing Receivable, Recorded Investment [Line Items]
Amount of loan losses related to institutional loans collectively evaluated for impairment	22,000,000	22,000,000
Institutional \| Senior Secured Bank Loans
Financing Receivable, Recorded Investment [Line Items]
Commercial and financial	375,000,000	0
Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Amount of loan losses related to institutional loans collectively evaluated for impairment	22,000,000	22,000,000
Loan modification, recorded investment	130,000,000	197,000,000
Impairment loss recognized	$ 0	$ 0

Carrying value as of the balance sheet date of payments made in excess of existing cash balances, which will be honored by the bank but reflected as a loan to the entity. Overdrafts generally have a very short time frame for correction or repayment and are therefore more similar to short-term bank financing than trade financing.

+ References+ Details

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(d))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph d

-Article 9

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 114

-Paragraph 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 8, 9

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph a(ii)

-Chapter V

-Subsection I

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

+ Details

- Definition

Amount before allowance of loans issued to financial institutions, including, but not limited to, real estate investment trusts, mortgage companies, and banks. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

+ References+ Details